The Psychosocial Factors Influencing Aggressive Driving ...Brien_Thesis.pdf · behaviour. Study One (n = 48) examined aggressive driving behaviour from the perspective of young drivers

The Psychosocial Factors Influencing Aggressive Driving Behaviour

Sharon Rosemary O’Brien

Bachelor of Social Science, Bachelor of Psychology (Honours)

A thesis submitted as fulfilment for the Degree of Doctor of Philosophy

Queensland University of Technology

Centre for Accident Research and Road Safety – Queensland (CARRS-Q)

School of Psychology & Counselling

Brisbane, Australia.

2011

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Key Words

Aggressive driving, road rage, aggression, young drivers, driving, road safety, stress,

psychopathology, emotions, threat, negative attributions.

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Abstract

Many drivers in highly motorised countries believe that aggressive driving is

increasing. While the prevalence of the behaviour is difficult to reliably identify, the

consequences of on-road aggression can be severe, with extreme cases resulting in

property damage, injury and even death. This research program was undertaken to

explore the nature of aggressive driving from within the framework of relevant

psychological theory in order to enhance our understanding of the behaviour and to

inform the development of relevant interventions.

To guide the research a provisional ‘working’ definition of aggressive driving

was proposed encapsulating the recurrent characteristics of the behaviour cited in the

literature. The definition was: “aggressive driving is any on-road behaviour adopted

by a driver that is intended to cause physical or psychological harm to another road

user and is associated with feelings of frustration, anger or threat”. Two main

theoretical perspectives informed the program of research. The first was Shinar’s

(1998) frustration-aggression model, which identifies both the person-related and

situational characteristics that contribute to aggressive driving, as well as proposing

that aggressive behaviours can serve either an ‘instrumental’ or ‘hostile’ function.

The second main perspective was Anderson and Bushman’s (2002) General

Aggression Model. In contrast to Shinar’s model, the General Aggression Model

reflects a broader perspective on human aggression that facilitates a more

comprehensive examination of the emotional and cognitive aspects of aggressive

behaviour.

Study One (n = 48) examined aggressive driving behaviour from the

perspective of young drivers as an at-risk group and involved conducting six focus

groups, with eight participants in each. Qualitative analyses identified multiple

situational and person-related factors that contribute to on-road aggression.

Consistent with human aggression theory, examination of self-reported experiences

of aggressive driving identified key psychological elements and processes that are

experienced during on-road aggression. Participants cited several emotions

experienced during an on-road incident: annoyance, frustration, anger, threat and

excitement. Findings also suggest that off-road generated stress may transfer to the

on-road environment, at times having severe consequences including crash

involvement. Young drivers also appeared quick to experience negative attributions

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about the other driver, some having additional thoughts of taking action.

Additionally, the results showed little difference between males and females in the

severity of behavioural responses they were prepared to adopt, although females

appeared more likely to displace their negative emotions. Following the self-

reported on-road incident, evidence was also found of a post-event influence, with

females being more likely to experience ongoing emotional effects after the event.

This finding was evidenced by ruminating thoughts or distraction from tasks.

However, the impact of such a post-event influence on later behaviours or

interpersonal interactions appears to be minimal.

Study Two involved the quantitative analysis of n = 926 surveys completed

by a wide age range of drivers from across Queensland. The study aimed to explore

the relationships between the theoretical components of aggressive driving that were

identified in the literature review, and refined based on the findings of Study One.

Regression analyses were used to examine participant emotional, cognitive and

behavioural responses to two differing on-road scenarios whilst exploring the

proposed theoretical framework. A number of socio-demographic, state and trait

person-related variables such as age, pre-study emotions, trait aggression and

problem-solving style were found to predict the likelihood of a negative emotional

response such as frustration, anger, perceived threat, negative attributions and the

likelihood of adopting either an instrumental or hostile behaviour in response to

Scenarios One and Two. Complex relationships were found to exist between the

variables, however, they were interpretable based on the literature review findings.

Factor analysis revealed evidence supporting Shinar’s (1998) dichotomous

description of on-road aggressive behaviours as being instrumental or hostile.

The second stage of Study Two used logistic regression to examine the

factors that predicted the potentially hostile aggressive drivers (n = 88) within the

sample. These drivers were those who indicated a preparedness to engage in direct

acts of interpersonal aggression on the road. Young, male drivers 17–24 years of age

were more likely to be classified as potentially hostile aggressive drivers. Young

drivers (17–24 years) also scored significantly higher than other drivers on all

subscales of the Aggression Questionnaire (Buss & Perry, 1992) and on the ‘negative

problem orientation’ and ‘impulsive careless style’ subscales of the Social Problem

Solving Inventory – Revised (D’Zurilla, Nezu & Maydeu-Olivares, 2002). The

potentially hostile aggressive drivers were also significantly more likely to engage in

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speeding and drink/drug driving behaviour. With regard to the emotional, cognitive

and behavioural variables examined, the potentially hostile aggressive driver group

also scored significantly higher than the ‘other driver’ group on most variables

examined in the proposed theoretical framework. The variables contained in the

framework of aggressive driving reliably distinguished potentially hostile aggressive

drivers from other drivers (Nagalkerke R2 = .39).

Study Three used a case study approach to conduct an in-depth examination

of the psychosocial characteristics of n = 10 (9 males and 1 female) self-confessed

hostile aggressive drivers. The self-confessed hostile aggressive drivers were aged

24–55 years of age. A large proportion of these drivers reported a Year 10 education

or better and average–above average incomes. As a group, the drivers reported

committing a number of speeding and unlicensed driving offences in the past three

years and extensive histories of violations outside of this period. Considerable

evidence was also found of exposure to a range of developmental risk factors for

aggression that may have contributed to the driver’s on-road expression of

aggression. These drivers scored significantly higher on the Aggression

Questionnaire subscales and Social Problem Solving Inventory Revised subscales,

‘negative problem orientation’ and ‘impulsive/careless style’, than the general

sample of drivers included in Study Two. The hostile aggressive driver also scored

significantly higher on the Barrett Impulsivity Scale – 11 (Patton, Stanford & Barratt,

1995) measure of impulsivity than a male ‘inmate’, or female ‘general psychiatric’

comparison group. Using the Carlson Psychological Survey (Carlson, 1982), the

self-confessed hostile aggressive drivers scored equal or higher scores than the

comparison group of incarcerated individuals on the subscale measures of chemical

abuse, thought disturbance, anti-social tendencies and self-depreciation. Using the

Carlson Psychological Survey personality profiles, seven participants were profiled

‘markedly anti-social’, two were profiled ‘negative-explosive’ and one was profiled

as ‘self-centred’.

Qualitative analysis of the ten case study self-reports of on-road hostile

aggression revealed a similar range of on-road situational factors to those identified

in the literature review and Study One. Six of the case studies reported off-road

generated stress that they believed contributed to the episodes of aggressive driving

they recalled. Intense ‘anger’ or ‘rage’ were most frequently used to describe the

emotions experienced in response to the perceived provocation. Less frequently

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‘excitement’ and ‘fear’ were cited as relevant emotions. Notably, five of the case

studies experienced difficulty articulating their emotions, suggesting emotional

difficulties. Consistent with Study Two, these drivers reported negative attributions

and most had thoughts of aggressive actions they would like to take. Similarly, these

drivers adopted both instrumental and hostile aggressive behaviours during the self-

reported incident. Nine participants showed little or no remorse for their behaviour

and these drivers also appeared to exhibit low levels of personal insight.

Interestingly, few incidents were brought to the attention of the authorities. Further,

examination of the person-related characteristics of these drivers indicated that they

may be more likely to have come from difficult or dysfunctional backgrounds and to

have a history of anti-social behaviours on and off the road.

The research program has several key theoretical implications. While many

of the findings supported Shinar’s (1998) frustration-aggression model, two key

areas of difference emerged. Firstly, aggressive driving behaviour does not always

appear to be frustration driven, but can also be driven by feelings of excitation

(consistent with the tenets of the General Aggression Model). Secondly, while the

findings supported a distinction being made between instrumental and hostile

aggressive behaviours, the characteristics of these two types of behaviours require

more examination. For example, Shinar (1998) proposes that a driver will adopt an

instrumental aggressive behaviour when their progress is impeded if it allows them

to achieve their immediate goals (e.g. reaching their destination as quickly as

possible); whereas they will engage in hostile aggressive behaviour if their path to

their goal is blocked. However, the current results question this assertion, since many

of the hostile aggressive drivers studied appeared prepared to engage in hostile acts

irrespective of whether their goal was blocked or not. In fact, their behaviour

appeared to be characterised by a preparedness to abandon their immediate goals

(even if for a short period of time) in order to express their aggression.

The use of the General Aggression Model enabled an examination of the three

components of the ‘present internal state’ comprising emotions, cognitions and

arousal and how these influence the likelihood of a person responding aggressively

to an on-road situation. This provided a detailed insight into both the cognitive and

emotional aspects of aggressive driving that have important implications for the

design of relevant countermeasures. For example, the findings highlighted the

potential value of utilising Cognitive Behavioural Therapy with aggressive drivers,

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particularly the more hostile offenders. Similarly, educational efforts need to be

mindful of the way that person-related factors appear to influence one’s perception of

another driver’s behaviour as aggressive or benign. Those drivers with a

predisposition for aggression were more likely to perceive aggression or ‘wrong

doing’ in an ambiguous on-road situation and respond with instrumental and/or

hostile behaviour, highlighting the importance of perceptual processes in aggressive

driving behaviour.

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Table of Contents

Key Words .................................................................................................................... i Abstract ....................................................................................................................... iii Table of Contents ........................................................................................................ ix Appendices ............................................................................................................... xvii List of Tables............................................................................................................. xix List of Figures ......................................................................................................... xxiii Glossary of Terms and Acronyms............................................................................ xxv Statement of Original Authorship ........................................................................... xxix Acknowledgements ................................................................................................. xxxi

Chapter One: Introduction ................................................................................... 1 1.1 Introductory Comments ...................................................................................... 3 1.2 Research Focus to Date ...................................................................................... 4 1.3 Theoretical Approach for the Research .............................................................. 6 1.4 Who are the Main Perpetrators? ......................................................................... 7 1.5 Research Objectives and Rationale .................................................................... 8 1.6 Scope of this Research ........................................................................................ 9 1.7 Methodological Approaches Used .................................................................... 10 1.8 Outline of the Thesis ......................................................................................... 10 1.9 Chapter Summary ............................................................................................. 12 Chapter Two: Aggressive Driving Literature Review ...................................... 13 2.1 Introduction....................................................................................................... 15 2.2 Defining Aggressive Driving ............................................................................ 15 2.2.1 The Distinction Between Aggressive Driving and ‘Road Rage’, and Other Ambiguities ....................................................................... 15 2.2.2 Emotional Catalysts for Aggressive Driving ...................................... 17 2.2.3 Aberrant Driving Behaviours to be Considered ................................. 18 2.2.4 Distinguishing Victims from Perpetrators .......................................... 18 2.2.5 Recurring Themes .............................................................................. 19 2.2.5.1 Emotion ................................................................................ 19 2.2.5.2 Behaviour ............................................................................. 19 2.2.5.3 Intentionality ........................................................................ 20 2.3 The Scope and Nature of Aggressive Driving .................................................. 23 2.3.1 Prevalence of Aggressive Driving ...................................................... 23 2.3.1.1 International Studies ............................................................. 23 2.3.1.2 Australian Studies ................................................................ 24 2.3.2 Types of Aggression on the Roads ..................................................... 25 2.4 Factors Contributing to Aggressive Driving..................................................... 27 2.4.1 Empirical Evidence ............................................................................ 27 2.4.2 Theoretical Perspective ...................................................................... 29 2.5 Person-Related Contributors to Aggressive Driving ........................................ 33 2.5.1 Age, Gender and Aggressive Driving ................................................ 33 2.5.2 Personality and Psychopathology ....................................................... 34 2.5.3 Trait Aggression ................................................................................. 37 2.5.4 Driving Anger ..................................................................................... 39 2.5.5 Impulsivity .......................................................................................... 41

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2.5.6 Sensation-Seeking .............................................................................. 41 2.5.7 Self-Esteem ......................................................................................... 42 2.5.8 Transfer of Stress to and from the On-Road Environment ................. 43 2.5.8.1 The Experience of Stress on the Road .................................. 44 2.5.8.2 Effect of Gender and Age on the Experience of Stress ........ 45 2.5.8.3 Driver Trait Stress Measures ................................................ 45 2.5.8.4 Individual Mood and Daily Hassles ..................................... 47 2.5.8.5 Life Event Stress................................................................... 48 2.5.8.6 Work Stress .......................................................................... 48 2.5.8.7 Fatigue .................................................................................. 49 2.6 Situational Contributors to Aggressive Driving ............................................... 49 2.6.1 On-Road Situational Factors .............................................................. 50

2.6.1.1 Type of Road ........................................................................ 50 2.6.1.2 Congestion ............................................................................ 51 2.6.1.3 Interim Summary .................................................................. 52

2.7 Issues Specific to At-Risk Drivers .................................................................... 53 2.7.1 Lifestyle .............................................................................................. 53 2.7.2 Education Attained ............................................................................. 54 2.7.3 Driving Experience ............................................................................. 54 2.7.4 Passenger Effect ................................................................................. 55 2.7.5 Motivation .......................................................................................... 56 2.7.6 Drugs and Alcohol .............................................................................. 57 2.8 Focus of Emerging Interventions ...................................................................... 58 2.8.1 Coping Styles in General .................................................................... 59 2.8.2 Driver Coping Strategies .................................................................... 62 2.9 Research Questions ........................................................................................... 63 2.10 Chapter Summary ............................................................................................. 65

Chapter Three: Aggression Literature Review .................................................... 67 3.1 Introduction ....................................................................................................... 69 3.1.1 Types of Human Aggression .............................................................. 69 3.2 Developmental Risk Factors for Aggression .................................................... 71 3.2.1 Historical Factors ................................................................................ 73 3.2.1.1 Personal History of Violence and Delinquency ................... 73 3.2.1.2 Family of Origin ................................................................... 73 3.2.1.3 Victims of Abuse .................................................................. 74 3.2.1.4 Negative Peer Relations ....................................................... 75 3.2.1.5 Schooling Problems .............................................................. 75 3.2.2 Clinical Factors ................................................................................... 76 3.2.2.1 Substance Abuse ................................................................... 76 3.2.2.2 Attitudes ............................................................................... 77 3.2.2.3 Emotional Regulation Difficulties ........................................ 78 3.2.2.4 High Impulsivity ................................................................... 80 3.2.2.5 General Life Stressors .......................................................... 82 3.2.3 Psychological Impact of Risk Factors ................................................ 83 3.3 Psychological Theories Relevant to Aggressive Driving ................................. 84 3.3.1 Frustration-Aggression Theory ........................................................... 84 3.3.2 Cognitive Neo-Associationistic Model .............................................. 85 3.3.3 Social Cognition Perspective .............................................................. 87 3.3.3.1 Social Learning ..................................................................... 87

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3.3.3.2 Causal Attribution – Fundamental Attribution Error ........... 90 3.3.4 Excitation Transfer Theory ................................................................. 90 3.3.5 Social Interaction Theory ................................................................... 92 3.4 Interim Summary .............................................................................................. 92 3.5 General Aggression Model ............................................................................... 93 3.5.1 Schemas and Script Theory ................................................................ 95 3.5.2 Situation and Person Factors as ‘Inputs’ for the GAM ...................... 95 3.5.3 The Process of Aggression According to the GAM ........................... 96 3.5.4 The Cognitive Appraisal Process in the GAM ................................... 98 3.5.5 Behavioural Outcomes According to the GAM ................................. 98 3.5.6 Applying Relevant Theory to the Phenomenon of Aggressive Driving ................................................................................................ 99 3.6 Additional Research Questions....................................................................... 101 3.7 Chapter Summary ........................................................................................... 102

Chapter Four: A Qualitative Study of Young Drivers as a High-risk Group 103 4.1 Introduction..................................................................................................... 105 4.2 Method ............................................................................................................ 106 4.2.1 Participants ....................................................................................... 106 4.2.2 Procedure .......................................................................................... 106 4.2.3 Materials ........................................................................................... 106 4.2.4 Analysis ............................................................................................ 108 4.3 Results and Exploration of the Qualitative Data ............................................ 108 4.3.1 Socio-Demographics and Driving Exposure .................................... 108 4.3.2 What is Considered Aggressive Driving? ........................................ 109 4.3.3 Perceived Causes of Aggressive Driving ......................................... 109 4.3.4 Situational factors ............................................................................. 110 4.3.4.1 Behaviours .......................................................................... 110 4.3.4.2 Facilitating Factors ............................................................. 112 4.3.4.2.1 Type of Vehicle ............................................... 113 4.3.4.2.2 Type of Road ................................................... 114 4.3.4.2.3 Vehicles On-Road and Pace of Living ............ 116 4.3.4.2.4 Time Pressure .................................................. 117 4.3.4.2.5 Passenger Effect .............................................. 118 4.3.4.2.6 Temperature ..................................................... 119 4.3.4.2.7 Music ............................................................... 119 4.3.5 Person-Related Factors ..................................................................... 119 4.3.5.1 State Factors ....................................................................... 119 4.3.5.1.1 Mood ............................................................... 119 4.3.5.1.2 Life-Stress ....................................................... 120 4.3.5.1.3 Job Stress ......................................................... 121 4.3.5.1.4 Driving Stress .................................................. 122 4.3.5.2 Trait Factors ....................................................................... 122 4.3.5.2.1 Age and Gender ............................................... 122 4.3.5.2.2 Personality ....................................................... 123 4.3.5.2.3 Prior Learning .................................................. 124 4.3.5.2.4 General Attitudes About Other Drivers ........... 125 4.3.5.3 General Transfer of Emotion to the On-Road Environment ....................................................................... 125

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4.3.5.4 Transfer of On-Road Generated Stress to the Off-road Environment ....................................................................... 127

4.3.6 Personal Experiences with Aggressive Driving ............................... 128 4.3.6.1 Victims or Perpetrators ....................................................... 129 4.3.6.2 Type of Road ...................................................................... 129 4.3.6.3 On-road Behavioural Causes .............................................. 130 4.3.6.4 Pre-event Emotional State .................................................. 132 4.3.6.5 Range of Emotions Experienced ........................................ 133 4.3.6.6 Cognitions During the Incident .......................................... 134 4.3.6.7 Behavioural Responses to On-Road Provocation............... 136 4.3.6.8 Post-Event State.................................................................. 138 4.3.6.9 Personal Accounts of Off-Road Stress Brought to the On-Road Environment........................................................ 139 4.4 Discussion ....................................................................................................... 141 4.4.1 Situational Factors ............................................................................ 141 4.4.2 State and Trait, Person-Related Causes ............................................ 142 4.4.3 Range of Emotions During an On-Road Incident ............................ 143 4.4.4 Cognitions During an On-Road Incident .......................................... 144 4.4.5 Behavioural Responses to On-Road Provocation ............................. 145 4.4.6 ‘Post Event State’ or Transfer to the Off-Road Environment .......... 146 4.4.7 Transfer of Emotions to the On-Road Environment ........................ 146 4.4.8 Coping Strategies Adopted by Young Drivers ................................. 147 4.4.9 Addressing the Research Questions ................................................. 148 4.4.10 Strengths and Limitations of the Study ............................................ 150 4.4.11 Implications of Findings for the Development of a Psychosocial Framework for Aggressive Driving .................................................. 151 4.4.12 Chapter Summary ............................................................................. 154

Chapter Five: A Quantitative Study of Aggressive Driving in Queensland .. 157 5.1 Introduction ..................................................................................................... 161 5.1.1 Overview of Research Questions and Relevant Hypotheses ............ 161 5.2 Method ............................................................................................................ 166 5.2.1 Participants ....................................................................................... 166 5.2.2 Design ............................................................................................... 167 5.2.3 Procedure .......................................................................................... 169 5.2.3.1 Scenarios............................................................................. 170 5.2.4 Materials ........................................................................................... 171 5.2.4.1 Standardised Measures Used .............................................. 171 5.2.4.1.1 Aggression Questionnaire................................ 171 5.2.4.1.2 Social Problem Solving Inventory – Revised .. 172 5.2.4.2 Research Specific Measures ............................................... 172

5.2.4.2.1 Pre-Study Emotional State............................... 173 5.2.4.2.2 Negative Emotional Response ......................... 173 5.2.4.2.3 Negative Attributions ...................................... 173 5.2.4.2.4 Behavioural Responses .................................... 174 5.2.4.2.5 Post-Event Influence........................................ 175

5.2.5 Statistical Analysis ........................................................................... 175 5.3 Results .......................................................................................................... 179 5.3.1 Data Cleaning and Testing Assumptions .......................................... 179 5.3.2 Psychometric Properties of the Standardised Measures ................... 179

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5.3.3 Factor Analysis of Research Specific Measures .............................. 180 5.3.3.1 Negative Emotions ............................................................. 180 5.3.3.2 Negative Attributions ......................................................... 181 5.3.3.3 Behavioural Responses ...................................................... 182 5.3.3.4 Post-Event Influence .......................................................... 184 5.3.4 Check of Pre-Study Emotions .......................................................... 184 5.3.5 Sample Characteristics ..................................................................... 185 5.3.5.1 Age and Gender of the Study Participants ......................... 185 5.3.5.2 Self-reported Driving Behaviour and Behavioural Intentions of the Sample ..................................................... 185 5.3.5.3 Trait Characteristics of the Sample .................................... 188 5.3.6 Emotional, Cognitive and Behavioural Responses to On-Road Incidents ........................................................................................... 189 5.3.7 Examination of the Components Proposed in the Theoretical Framework of Aggressive Driving ................................................... 190 5.3.7.1 Bi-variate Correlations of Variables for Consideration in the Examination of the Components of the Framework .... 191 5.3.7.1.1 Driving Exposure and Socio-Demographic Variables .......................................................... 191 5.3.7.1.2 Negative Emotions .......................................... 192 5.3.7.1.3 Perceived Threat .............................................. 192 5.3.7.1.4 Negative Attributions ...................................... 193 5.3.7.1.5 Instrumental Behavioural Response ................ 193 5.3.7.1.6 Hostile Aggressive Behavioural Response ...... 195 5.3.7.1.7 Post-Event Influence ....................................... 195 5.3.7.1.8 Self-Reported Measures for the Two Scenarios ......................................................... 196 5.3.7.2 Regression Analyses of Socio-Demographic, Trait and State Person-Related Variables on Participant Emotional, Cognitive and Behavioural Responses ............ 197 5.3.7.2.1 Negative Emotions .......................................... 198 5.3.7.2.2 Perceived Threat .............................................. 200 5.3.7.2.3 Negative Attributions ...................................... 202 5.3.7.3 Regression of Socio-Demographic, Trait and State Person-Related and Emotional and Cognitive Response Variables on Participant Behavioural Responses ............... 205 5.3.7.3.1 Likelihood of an Instrumental Behavioural Response .......................................................... 205 5.3.7.3.2 Likelihood of a Hostile Behavioural Response .......................................................... 208 5.3.7.4 Regression of Socio-Demographic, Trait and State Person-Related, Emotional and Cognitive Response and Behavioural Response Variables on the Likelihood of a Post-Event Influence .......................................................... 212 5.3.8 Exploratory Analyses of Potentially Hostile Aggressive Drivers .... 215 5.3.8.1 Rationale ............................................................................. 215 5.3.8.2 PHA Driver Selection ......................................................... 215 5.3.8.3 Socio-demographic and Driving Characteristics of the PHA Drivers ....................................................................... 216 5.3.8.4 PHA Driver Differences in Trait Characteristics ............... 217

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5.3.8.5 PHA Driver Self Reported Driving Behaviour and Behavioural Intentions........................................................ 218 5.3.8.6 PHA Driver Emotional, Cognitive and Behavioural Responses ........................................................................... 219 5.3.8.7 Ability of Variables to Predict PHA Driver Group Membership ........................................................................ 221 5.4 Discussion ....................................................................................................... 222 5.4.1 Response Differences to On-Road Scenarios ................................... 223 5.4.2 Exploration of the Components of the Proposed Theoretical Framework of Aggressive Driving ................................................... 225 5.4.3 The Nature and Purpose of Aggressive Driving Behaviours ........... 236 5.4.4 Exploration of the PHA Driver Findings .......................................... 236 5.4.4.1 Socio-Demographic and Driving Characteristics of the PHA Driver ......................................................................... 236 5.4.4.2 PHA Driver History of Driving Offences in the Previous Three Years ......................................................... 238 5.4.4.3 PHA Driver Self-reported Driving Behaviour ................... 238 5.4.4.4 Differences in Psychological Characteristics ..................... 239 5.4.4.5 PHA Driver Emotional, Cognitive and Behavioural Responses ........................................................................... 240 5.4.4.6 Prediction of PHA Group Membership .............................. 241 5.4.5 Implications for the Proposed Theoretical Framework of Aggressive Driving ........................................................................... 241 5.4.6 Overview of Findings and Theoretical Implications ........................ 243 5.4.7 Study Limitations ............................................................................. 244 5.4.8 Chapter Summary ............................................................................. 246 Chapter Six: Examination of the Psychosocial Characteristics of Self- Reported Hostile Aggressive Drivers ....................................... 249 6.1 Introduction ..................................................................................................... 253 6.1.1 Relevant Research Questions and Areas to be Explored .................. 254 6.2 Method .......................................................................................................... 255 6.2.1 Design ............................................................................................... 255 6.2.2 Procedure .......................................................................................... 257 6.2.3 Participants ....................................................................................... 257 6.2.4 Statistical Analysis ........................................................................... 258 6.2.5 Measures ........................................................................................... 258 6.2.5.1 Stressful Life Experiences Screening ................................. 258 6.2.5.2 Aggression Questionnaire .................................................. 259 6.2.5.3 Social Problem Solving Inventory – Revised ..................... 259 6.2.5.4 Carlson Psychological Survey ............................................ 259 6.2.5.5 Barratt Impulsiveness Scale – Version 11 (BIS-11) ........... 261 6.3 Results .......................................................................................................... 263 6.3.1 Socio-Demographics ........................................................................ 263 6.3.2 Driving Characteristics ..................................................................... 263 6.3.3 History of Driving Offences and Charges ........................................ 264 6.3.4 Historical Background ...................................................................... 264 6.3.4.1 Familial Backgrounds ......................................................... 264 6.3.4.2 Victims of Abuse/Neglect .................................................. 264

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6.3.4.3 History of Delinquency and/or Violence ........................... 265 6.3.4.4 Negative Peer Associations ................................................ 265 6.3.4.5 History of School Conduct Problems ................................. 266 6.3.4.6 Clinical History .................................................................. 266 6.3.5 Clinical Background ......................................................................... 266 6.3.5.1 Trait Aggression ................................................................. 268 6.3.5.2 Social Problem Solving ...................................................... 268 6.3.5.3 Impulsivity ......................................................................... 268 6.3.5.4 Carlson Psychological Survey (CPS) ................................. 269 6.3.5.4.1 Chemical Abuse (CA) ..................................... 269 6.3.5.4.2 Thought Disturbance (TD) and Validity (VAL) ................................................ 270 6.3.5.4.3 Anti-Social Tendencies (AT) .......................... 271 6.3.5.4.4 Self-Deprecation (SD) ..................................... 272 6.3.5.5 CPS Typing ........................................................................ 272 6.3.6 Qualitative Analysis of Hostile Aggressive Driving Incidents ........................................................................................... 273 6.3.6.1 Situational On-Road Triggers ............................................ 273 6.3.6.1.1 Road Characteristics ........................................ 273 6.3.6.1.2 Passenger Effect .............................................. 273 6.3.6.1.3 Gender of the Other Driver ............................. 273 6.3.6.1.4 Reference to the Other Driver's Vehicle.......... 273 6.3.6.1.5 Behavioural Triggers ....................................... 274 6.3.6.1.6 Range of 'Other Driver' Behaviours ................ 274 6.3.6.1.7 Perceived Attitude of 'Other Driver' ................ 275 6.3.6.2 Situational Off-Road Triggers ............................................ 276 6.3.6.3 Emotional Responses ......................................................... 276 6.3.6.4 Cognitive Responses .......................................................... 278 6.3.6.5 Physiological Arousal ........................................................ 279 6.3.6.6 Behaviours Engaged by Hostile Aggressive Driver Group ...................................................................... 279 6.3.6.7 Consequences of the Hostile Aggressive Driver Behaviour ................................................................ 281 6.3.6.8 General Attitudes of the Hostile Aggressive Driver .......... 282 6.3.6.9 Lack of Personal Insight ..................................................... 283 6.3.6.10 Other Experiences as the Perpetrator ................................. 283 6.4 Discussion ....................................................................................................... 283 6.4.1 Case Study Experiences as a Hostile Aggressive Driver ................. 284 6.4.1.1 On-road situational factors ................................................. 284 6.4.1.2 Situational Off-Road Triggers ............................................ 285 6.4.1.3 Emotional Responses ......................................................... 286 6.4.1.4 Cognitive Responses .......................................................... 286 6.4.1.5 Physiological Arousal ........................................................ 287 6.4.1.6 Behaviours Adopted by the Hostile Aggressive Driver ..... 288 6.4.1.7 Consequences of the Hostile Aggressive Driver Behaviour ........................................................................... 288 6.4.1.8 General Attitude of the Hostile Aggressive Driver ............ 289 6.4.1.9 Levels of Personal Insight in the Hostile Aggressive Driver ................................................................................. 289 6.4.1.10 Other Experiences as the Perpetrator ................................. 290

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6.4.2 Person-Related Characteristics of the Hostile Aggressive Driver Group ..................................................................................... 290 6.4.3 Exposure to Developmental Risk Factors for Aggression ................ 292 6.4.4 Trait Person-Related Characteristics ................................................ 295 6.4.5 General Psychological Characteristics ............................................. 296 6.4.6 Hostile Aggressive Drivers and the Theoretical Framework of Aggressive Driving ........................................................................... 299 6.4.7 Strengths and Limitations of the Research ....................................... 302 6.4.8 Recommendations for Future Research ............................................ 303 6.4.9 Chapter Summary ............................................................................. 304 Chapter Seven: Discussion.................................................................................... 305 7.1 Introduction ..................................................................................................... 307 7.2 Review of Findings ......................................................................................... 307 7.3 Review of the Provisional Definition ............................................................. 315 7.4 Theoretical Implications ................................................................................. 316 7.5 Implications for Road Safety .......................................................................... 318 7.5.1 Public Intervention Implications ...................................................... 319 7.5.2 Targeting Young Drivers .................................................................. 320 7.5.3 Targeting Professional Drivers ......................................................... 321 7.5.4 Targeting Convicted Aggressive Drivers ......................................... 321 7.5.5 Evaluation of Strategies .................................................................... 322 7.5.6 Penalties and Sanctions Associated with Aggressive Driving ......... 323 7.6 Strengths and Limitations of the Research ..................................................... 323 7.7 Recommendations for Future Research .......................................................... 325 7.8 Concluding Remarks ....................................................................................... 326 References ................................................................................................................ 327 Appendices ............................................................................................................... 357

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Appendices

A Participant Information and Consent Package – Study One ...................................... 358 B Socio-Demographic questionnaire – Study One ........................................................ 360 C Focus Group Protocols – Study One ......................................................................... 363 D SPSS Output Socio-Demographic and Driving Exposure Data-Study One .............. 367 E RACQ Sample Details ............................................................................................... 371 F Study Two Questionnaire .......................................................................................... 372 G Questionnaire Coverpage – RACQ participants ........................................................ 381 H Questionnaire Coverpage – QUT participants ........................................................... 382 I Internal Reliability Measures for Measures in the Study Two Questionnaire ........... 385 J Analyses of Driving Behaviour Characteristics and Behavioural Intentions of the Study Two Sample .......................................................................................... 393 K Differences in Trait Characteristics of the Study Two Sample ................................. 395 L PHA Driver results from the Study Two Sample ...................................................... 399 M Semi-structured Questionnaire – Study Three ........................................................... 405 N Interview Protocols – Study Three ............................................................................ 421 O Advertisement for Recruiting – Men’s Information and Support Association .......... 423 P Participant Consent Package – Study Three .............................................................. 424 Q Published M and SD associated with CPS and BIS 11 Measures .............................. 426 R Range of CPS Subscale Scores by Offender Type .................................................... 428 S Brief Descriptor of CPS Offender Type .................................................................... 438 T Individual Participant Scores on the AQ and SPSI-R and Significance Levels – Study Three ................................................................................................. 439 U Individual Participant Scores on the BIS-11 and CPS and Significance Levels – Study Three ................................................................................................. 440 V Individual Participant Case Studies – Study Three ................................................... 441

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List of Tables Table 4.1 References made to vehicle characteristics ...................................... 113 Table 4.2 Types of vehicles identified as being more likely to be involved in aggressive driving......................................................................... 114 Table 4.3 Type of road characteristics identified as typically associated with aggressive driving..................................................................... 115 Table 4.4 Perceived increase in number of vehicles on the road and increased pace of living .................................................................... 117 Table 4.5 Role of time pressure ........................................................................ 117 Table 4.6 The influence of passengers upon driving behaviour ....................... 118 Table 4.7 Influence of music upon driving behaviour...................................... 119 Table 4.8 Participant responses relating to influence of mood upon driving behaviour .......................................................................................... 120 Table 4.9 Life-stress and potential impacts upon aggressive driving ............... 121 Table 4.10 Participant responses relating to job stress ....................................... 121 Table 4.11 Participant responses relating to driving stress ................................ 122 Table 4.12 Perceptions of young drivers and other road users ........................... 123 Table 4.13 Participant references to personality tendencies for aggressive driving behaviour.............................................................................. 124 Table 4.14 Prior exposure to aggression cited by participants ........................... 124 Table 4.15 General attitudes of the ‘other driver’ .............................................. 125 Table 4.16 Sources of off-road emotion transferred to the on-road environment ...................................................................................... 126 Table 4.17 Coping strategies adopted following an aggressive driving incident ............................................................................................. 128 Table 4.18 On-road precipitating behaviours from personal experiences with aggressive driving..................................................................... 130 Table 4.19 Frustrating or anger-provoking behaviour of other drivers .............. 132 Table 4.20 Above average positive emotions reported prior to the event .......... 133 Table 4.21 Range of primary emotions experienced .......................................... 134 Table 4.22 Participant comments associated with range of emotions ................ 134 Table 4.23 Cognitions associated with reported aggressive driving incidents ... 135 Table 4.24 Behavioural responses adopted by participants in response to perceived provocation in recalled aggressive driving incidents ....... 136 Table 4.25 Outwardly aggressive behavioural responses to personal experiences with aggressive driving ................................................. 137 Table 5.1 Breakdown of individual variables into broader subject categories .......................................................................................... 169 Table 5.2 Items in the negative attribution scale .............................................. 174 Table 5.3 Questionnaire behavioural response set ........................................... 174 Table 5.4 Items in post-event experiences........................................................ 175 Table 5.5 Means and standard deviations of trait characteristics (n=926) ....... 180 Table 5.6 Factor loadings for negative emotional response for Scenarios One and Two .................................................................................... 181 Table 5.7 Factor loadings for negative attribution factor for Scenarios One and Two ............................................................................................ 181 Table 5.8 Factor loadings of behavioural response set for Scenarios One and Two ............................................................................................ 183

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Table 5.9 Factor loadings of items onto likelihood of post-event influence for Scenarios One and Two .............................................................. 184 Table 5.10 Age and gender of the participants by source ................................... 185 Table 5.11 Driving behaviour characteristics and behavioural intentions of the sample ..................................................................................... 187 Table 5.12 Pairwise t-tests of mean emotional, cognitive and behavioural responses to Scenarios One and Two ............................................... 190 Table 5.13 Bivariate correlations of the person-related, driving exposure, emotional, cognitive and behavioural responses, and post-event influence variables – Scenario One (S1) and Scenario Two (S2) (N=926) ............................................................................................ 194 Table 5.14 Bivariate correlations of participant negative emotion, threat, negative attributions, likelihood of behavioural response and post-event influence - Scenarios One and Two ................................ 197 Table 5.15 Hierarchical regression of socio-demographic, trait and state person-related variables on participant negative emotion responses to Scenario One (n=926) .................................................. 198 Table 5.16 Hierarchical regression of socio-demographic, trait and state person-related variables on participant negative emotion responses to Scenario Two (n=926) ................................................. 199 Table 5.17 Hierarchical regression of socio-demographic, trait and state person-related variables on participant perceived threat responses to Scenario One (n=926) .................................................. 201 Table 5.18 Hierarchical regression of socio-demographic, trait and state person-related variables on participant perceived threat responses to Scenario Two (n=926) ................................................. 202 Table 5.19 Hierarchical regression of socio-demographic, trait and state person-related variables on participant negative attributions in response to Scenario One (n=926) .................................................... 203 Table 5.20 Hierarchical regression of socio-demographic, trait and state person-related variables on participant negative attributions in response to Scenario Two (n=926) ................................................... 204 Table 5.21 Hierarchical regression of socio-demographic, trait and state

person-related and emotional and cognitive response variables on participant instrumental response to Scenario One (n=926) ....... 206

Table 5.22 Hierarchical regression of socio-demographic, trait and state person-related and emotional and cognitive response variables on participant instrumental response to Scenario Two (n=926) ....... 207 Table 5.23 Hierarchical regression of socio-demographic, trait and state person-related and emotional and cognitive response variables on participant hostile response to Scenario One (n=926) ................. 210 Table 5.24 Hierarchical regression of socio-demographic, trait and state person-related and emotional and cognitive response variables on participant hostile response to Scenario Two (n=926) ................ 211 Table 5.25 Hierarchical regression of socio-demographic, trait and state person-related, emotional, cognitive and behavioural response variables on the likelihood of a post-event influence to Scenario One (n=926) ...................................................................................... 213

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Table 5.26 Hierarchical regression of socio-demographic, trait and state person-related, emotional, cognitive and behavioural response variables on the likelihood of a post-event influence to Scenario Two (n=926) ..................................................................................... 214 Table 5.27 Breakdown of Gender by Age for the PHA Driver Group (n=88) ... 216 Table 6.1 Independent sample t-tests of self-reported hostile aggressive Drivers on AQ and SPSI-R subscales compared to overall study two sample (n = 926) .............................................................. 267 Table 6.2 Independent sample t-tests of self-reported hostile aggressive Drivers on AQ and SPSI-R subscales compared to the PHA drivers identified in study two (n = 88) ............................................ 267 Table 6.3 References made about the vehicles of the ‘other drivers’ ............... 274 Table 6.4 Examples of primary behavioural trigger for aggressive driving incidents ............................................................................................ 274 Table 6.5 Subsequent behaviours adopted by the ‘other driver’ ...................... 275 Table 6.6 References to the perceived attitudes of the other drivers ................ 275 Table 6.7 Pre-event off-road stressors cited by participants ............................ 276 Table 6.8 Examples of range of emotions experienced by participants ........... 277 Table 6.9 Examples of the negative cognitions associated with hostile aggressive drivers ............................................................................. 278 Table 6.10 Range of physiological changes identified by the case studies ........ 279 Table 6.11 Range of behaviours adopted by the hostile aggressive driver group ................................................................................................. 280 Table 6.12 Examples of real or perceived consequences ................................... 281 Table 6.13 General attitudes of the hostile aggressive driver group .................. 282 Table 6.14 Comments illustrating difficulty with personal insight .................... 283

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List of Figures Figure 2.1 Relationship of risky driving behaviours to aggressive driving behaviours........................................................................................... 22 Figure 2.2 Conditions influencing driver behaviour ............................................ 28 Figure 2.3 Frustration-Aggression Model of Aggressive Driving ....................... 30 Figure 3.1 The General Aggression Model.......................................................... 94 Figure 3.2 Expanded appraisal and decision-making processes of the GAM ..... 97 Figure 4.1 Map of concepts explored in accordance with the GAM ................. 107 Figure 4.2 Participant responses to the causes of aggressive driving behaviour by major themes identified .............................................. 111 Figure 4.3 Theoretical framework of psychosocial processes underpinning aggressive driving ............................................................................. 151 Figure 5.1 Diagrammatic presentation of the three stage exploration of theoretical components ..................................................................... 177

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Glossary of Terms and Acronyms

Aberrant Driving Behaviour Aberrant driving behaviours are those that deviate from normal, law-abiding behaviours. Anger Anger is an emotional state, a strong feeling of annoyance, displeasure, or hostility. Behavioural Factors This term is used to refer collectively to both the instrumental and hostile behaviours identified in Study Two. BIS – 11 Barratt Impulsiveness Scale – Version 11 (BIS-11) (Patton & Barratt, 1995), a measure of the first order personality trait, impulsivity. This measure consists of three main components: motor impulsiveness, attentional impulsiveness, and non-planning. Catharsis In lay terms refers to any cleansing or purging of emotions (Reber & Reber, 2001). When considered in the context of Frustration-Aggression Theory (Dollard et al., 1939), ‘catharsis’ or the expression of feelings such as frustration or anger serves to return the frustration threshold to the ‘normal’ or ‘baseline’ level. CBT Cognitive-behaviour therapy. CPS The Carlson Psychological Survey (CPS) (Carlson, 1982) is primarily designed for use with individuals who have been accused or convicted of crimes, or otherwise referred for socially deviant behaviour. Decision Making Model The decision making model is a component of the GAM (Anderson & Bushman, 2002). This part of the model involves an individual’s appraisal of a given situation and the decision making that will result in either thoughtful or impulsive behavioural responses.

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Emotional and Cognitive Response An ‘emotional and cognitive response’ in this thesis refers to the immediate emotional, cognitive and physiological response following exposure to an anger-provoking scenario. Frustration Frustration is an emotional response to circumstances, resulting in feeling dissatisfied or unfulfilled when prevented from progressing or succeeding with one’s plans or actions. GAM The General Aggression Model (Anderson & Bushman, 2002). Impulsivity A term used to refer to the trait tendency for an individual to react quickly on the basis of the first thing that comes to mind (Reber & Reber, 2001). Negative Attributions A term used in social psychology concerning perception. Negative attributions involve the making of negative inferences about the intention and motivation of another individual’s behaviour. Negative Emotions This term was used to collectively refer to emotions that are likely to precede frustration/anger. Person-related Factors A term used to refer to those factors that originate from within an individual. For example, trait factors such as personality, and state factors such as stress are considered person-related factors. Post-event Influence This term refers to the possible post-event influence that may result from an on-road encounter considered aggressive. This influence was measured in terms of the likelihood of the incident influencing a person during the rest of their journey, in the performance of other tasks or in dealings with others. Potentially Hostile Aggressive Driver A term used to refer to those drivers identified in Study Two (n = 88) as having a greater preparedness to perpetrate hostile aggressive behaviours on the road.

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Present Internal State The ‘present internal state’ is a component of the General Aggression Model (Anderson & Bushman 2002). This component consists of social cognitions, affect and arousal as a result of exposure to a potentially provocative incident. Reactive Aggression Reactive aggression is used as a general term to refer to the aggression adopted in response to real or perceived on-road provocation. Situational Factors A general term used to refer to all the characteristics of a situation to which one is exposed whilst driving. This may include indirect characteristics such as the type of road, level of on-road congestion, as well as more direct causes such as on-road provocative behaviour. SLES-S Stressful Life Experiences Screening – Short Form (SLES-S) (Hudnall & Stamm, 1996). This is a survey that screens for major life events that may be considered stressful and significant in a person’s life. Social Information Processing Social information processing is a term that refers to the processing of information within any given social setting. This process relies on the principles of computer logic focusing on the inputs, internalised processes and outcomes of a social encounter (Reber & Reber, 2001; Zelli, Dodge, Lochman & Laird, 1999). SPSI-R The Social Problem Solving Inventory – Revised (SPSI-R) (D’Zurilla, Nezu & Maydeu-Olivares, 2002), is a measure of trait social problem solving style. Three of the five subscales were used as measures in this thesis: NPO – negative problem orientation; ICS – impulsive/careless style; and RPS – rational problem solving. State Stress Stress or anxiety that is relatively short-term, resulting from situational stressors such as driving. Stereotypes Stereotypes are a set of relatively fixed, simplistic over-generalisations about a group or class of people (Reber & Reber, 2001).

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Trait stress Trait stress is feelings of stress or anxiety stemming from personality traits that are relatively enduring.

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Statement of Original Authorship

The work contained in this thesis has not been previously submitted for a degree or

diploma at any other higher education institution. To the best of my knowledge and

belief, this thesis contains no material previously published or written by another

person except where due reference is made.

Signed: ……………………………………

Date: ………………………………………

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Acknowledgements

There are a number of people I would like to thank for their varied

contributions towards the completion of this thesis. Firstly, I would like to thank

CARRS-Q for the scholarship that I received during the first three years of this

process. Without funding it would not have been possible for me to undertake the

research project. Secondly, I wish to thank my Supervisor Dr Barry Watson for his

patience and guidance throughout the project. Other professionals that at some stage

have been identified as Associate-Supervisors include Dr Gavan Palk, Mrs Cynthia

Schonfeld, Dr Graham Fraine and Professor Richard Tay. I would like to thank these

individuals for their varied and valued contributions to the research program. I

would also like to thank Professor Mary Sheehan and Dr Robert Schweitzer for their

time and advice concerning the articulation of this research from a Masters to a PhD

and their further advice concerning the methodology for Study Three. I would also

like to take the opportunity to thank my fellow post-graduate students who have

given me tremendous support over the four years.

Finally, but most importantly, I wish to thank my family. The completion of

the project was only possible due to every contribution of childcare and/or assistance

made by my elderly parents. Also critical to my success is the fact that I have two

terrific children. Without their many personal sacrifices, most of the sacrifices made

in a good natured way, the completion of the project would not have been possible.

Psychosocial Characteristics of Aggressive Drivers 1

Chapter One: Introduction

1.1 Introductory Comments ............................................................................................. 3

1.2 Research Focus to Date .............................................................................................. 4

1.3 Theoretical Approach for the Research...................................................................... 6

1.4 Who are the Main Perpetrators? ................................................................................. 7

1.5 Research Objectives and Rationale ............................................................................ 8

1.6 Scope of this Research ............................................................................................... 9

1.7 Methodological Approaches Used ........................................................................... 10

1.8 Outline of the Thesis ................................................................................................ 10

1.9 Chapter Summary..................................................................................................... 12



1.1 Introductory Comments

Many drivers in highly motorised countries including those in the United

Kingdom, American, Canada and Israel believe that aggressive driving behaviour is on

the increase (AAMI, 2001, 2002, 2003; Deffenbacher, Oetting, & Lynch, 1994;

Lajunen, Parker, & Stradling, 1999; Shinar, 1998; Wiesenthal & Hennessy, 1999).

Some researchers have suggested that this perceived increase in aggressive driving may

be due to increasing numbers of vehicles competing for limited road infrastructure,

which results in an increase in congestion and competition for road space, and a sense of

pressure for the greater economic use of time impacting on driver frustration levels

(Connell & Joint, 1996; IIHS, 1997; Lajunen, Parker, & Summala, 1999; Mizell, 1997;

Shinar, 1998).

In a recent Victorian Parliamentary inquiry into the violence associated with

motor vehicle use, the Drugs and Crime Prevention Committee (DCPC) acknowledged

the growing concern of general motorists about the issue (DCPC, 2005). They also

acknowledged the pivotal influence of the media in the formulation of public

perceptions about the phenomenon. Despite the power of the media to inflate public

perceptions about aggressive driving, they report numerous acts of extreme on-road

aggression that are worthy of public attention. The Committee analysed 55 reports that

mentioned ‘road rage’ in The Age and The Herald Sun newspapers between 1999 and

2004. Of the 35 individuals that reportedly sustained physical injuries, the injuries

included serious head injuries, being knocked unconscious (one in a coma), bullet

wounds, fractures, various levels of bruising, and death. Although such extreme

instances are rare they can result in serious physical assault and sometimes death.

Further to concerns for the physical safety of the general road-user, there is also an

increasing concern for public liability costs and the costs associated with damage to

vehicles that may result from aggressive driving behaviour. In the final report by the

DCPC (2005), the committee attempted to review the costs associated with aggressive

driving in Victoria by accessing police statistics, road safety and insurance agencies,

though it was acknowledged that many aggressive driving incidents fail to be reported.

Victorian Police statistics revealed that of 1,524 incidents recorded the cost of property

damage ranged from zero to $28,000 (mean value $174.24). When insurance agency


data was examined it became obvious that most agencies do not identify claims as

resulting from aggressive driving or ‘road-rage’. Therefore, the cost was difficult to

quantify. Notwithstanding this, in 1997 the AAMI reported that more than 50% of its

claims were attributable to aggressive driving behaviour and the resultant vehicle

damage, the estimated total cost being $1.7 billion (VCCAV, 1999, p. 17, citing Herald

Sun, 12 April 1997). Therefore, the negative economic implications of aggressive

driving also appear to be real and further research is required to clarify the reasons some

drivers adopt aggressive, and sometimes lethal, behaviours whilst driving.

While aggressive driving appears to have real implications in terms of physical

harm and financial costs, road traffic researchers have identified a number of difficulties

hampering our understanding of the problem. When attempting to examine this issue

researchers have had considerable difficulty defining the phenomenon. Should it be

termed ‘road rage’ or ‘aggressive driving’? What is the difference between the two

terms? Hence, the beginning of Chapter Two will discuss these issues in greater depth

in order to formulate a working definition for the purpose of this research.

1.2 Research Focus to Date

A small number of researchers have focussed on the contextual/situational

factors that contribute to on-road aggressive behaviours (Shinar, 1998; O’Brien, Tay, &

Watson, 2005) while others have focussed on the individual driver characteristics

brought to the on-road environment (Deffenbacher et al., 1994; Lajunen & Parker, 2001;

Shinar, 1998). Much of this research has been conducted utilising psychological theory

relevant to the single contextual or person-related factors under investigation. For

instance, the study by O’Brien and colleagues (2004) examined two person-related

factors that were found to influence aggressive driving outcomes, namely the age and

gender of the ‘offending driver’. This study was based upon social information

processing theory (Zelli, Dodge, Lochman, & Laird, 1999) and examined the use of

negative attributions in the context of driving. Further, research suggests that the

availability and/or adoption of such thoughts can be the result of developmental

exposure to aggressive or negative role models. These factors are generally known as

risk factors for aggression.


General aggression research has identified a number of risk factors for

aggression that appear to increase the likelihood of aggressive tendencies and the

adoption of aggressive behaviours in response to provocation. These risk factors are

discussed in more detail in Chapter Three. The results indicate that such factors may

have a negative influence upon an individual at a trait, person-related level. Also,

between provocation and an aggressive behavioural response, an individual is required

to initially perceive and interpret his/her environment (or situation) as aggressive. Thus

perception and interpretation, mediated by such risk factors, appear to influence the

likelihood of adopting an aggressive response to one’s environment. Hence, there is a

need to examine psychological theories that have been used to explain aggression in the

wider context.

A wide range of psychological theories have been used to explain general human

aggression including social cognition theories, frustration-aggression theory, cognitive

neo-associationistic and excitation transfer theory (Bandura, 1977; Berkowitz, 1993;

Zillmann, 1988). This thesis also acknowledges the important role of the biological

contributors to aggression such as serotonin and genetics, although they are beyond the

scope of this research. Of the psychosocial theories above, to date only social cognition

theories and frustration-aggression theory have been used to examine aggressive driving

behaviour (Shinar, 1998; Yagil, 2001).

To date, few pieces of research have investigated the whole phenomenon of

aggressive driving from within a framework that has been based upon psychological

theory i.e. frustration-aggression theory (Dollard, Doob, Mowrer, Miller, & Sears, 1939;

Shinar, 1998). Although frustration-aggression theory is highly relevant to aggressive

driving, research has found that high levels of frustration/anger do not necessarily lead

to outward expressions of aggression, in either the on or off-road environments

(Berkowitz, 1993; Lajunen & Parker, 2001). As such, some aggression researchers

would suggest that the resultant effect is the displacement of such built-up frustration or

aggression to another, subsequent point in time (Dollard et al., 1939; Shinar, 1998).

Therefore, there appears to be some other ‘process’ or personal characteristics

underlying the likelihood of expressing aggression at a particular point in time that may

be better explained through other psychological theories of aggression. Consideration of


other theories may also assist in identifying groups that are at high risk of participating

in such behaviour.

Despite the commendable, though somewhat piece-meal, nature of research to

date, a number of papers proposing interventions for aggressive driving behaviour have

started to emerge (Deffenbacher, Filetti, Lynch, Dahlen, & Oetting, 2002; Galovski,

Blanchard, Malta, & Freidenberg, 2003). Although, some of these interventions are

based in well-established therapeutic methods, such as cognitive behaviour therapy

(CBT), the multiple causes of aggressive driving behaviour have not been explored in

terms of the underlying psychological components that contribute to the phenomenon.

Indeed, there appears to be a lack of data concerning the psychological processes that

characterise aggressive driving.

Examination of these processes would help clarify the type and extent of

countermeasures required for various levels of intervention. For instance, it is likely that

more serious offenders who face criminal charges would require a somewhat more

intensive ‘intervention’ than that possible through mainstream driver education

programs. Additionally, examination of these processes may assist in highlighting

psychological differences between those drivers who are more likely to adopt extreme

forms of aggression on the road than general road users.

1.3 Theoretical Approach for the Research

The General Aggression Model (GAM) (Anderson & Bushman, 2002),

encapsulates a number of human aggression theories with potential relevance for

aggressive driving research. The GAM also emphasises the cognitive elements and

decision-making processes involved in human aggression. Consequently, the GAM was

selected as the theoretical framework for this research, with the hope that it would

provide a deeper understanding about the psychosocial processes involved in the

expression of aggression on the roads, thus enabling the development of research-based

recommendations for intervention and rehabilitation. Moreover, because it encapsulates

the major theories of human aggression, it may facilitate a more thorough understanding

of why certain drivers, in particular, are prepared to adopt aggressive driving behaviour.

The GAM is discussed in greater detail in Chapter Three.


1.4 Who are the Main Perpetrators?

In a comprehensive review of the characteristics of aggressive drivers and

Australian media reports of ‘road-rage’, the DCPC (2005) reported that although

younger drivers appear to be the most common perpetrators of lesser acts of on-road

aggression, driver age is less of an issue in the perpetration of more extreme acts of on-

road aggression. Hence, drivers of a wide age range appear capable of perpetrating acts

of extreme aggression or violence on the road, similar to the incidence of other violent

crimes (DCPC, 2005).

Other research has identified young drivers as a specific at-risk group for

aggressive driving behaviour. For instance, Shinar (1998) has found that as driver age

increases, aggressive driving seems to decrease. Lajunen and colleague (1999) also

reported that aggressive driving was more common among men than women,

particularly the more severe expressions of aggressive driving. These results are

consistent with the findings of VCCAV (1999), which found that people aged 18–34

years, particularly males, were significantly more likely to participate in ‘mild’ ‘road

rage’ than other drivers. In ‘severe’ cases of ‘road rage’ males aged 18–24 years were

more likely to display severe behavioural responses. Young males have also been found

to be over-represented in a study of New South Wales police records of reported

aggressive driving incidents (Harding, Morgan, Indermaur, Ferrante, & Blagg, 1998). In

contrast, other research suggests that an increasing number of young female drivers are

actively participating in acts of aggressive driving (Lajunen & Parker, 2001; Lawton &

Nutter, 2002). Specifically, females appear to be more likely to adopt displaced or

suppressed aggression, whilst males were found to report higher levels of outwardly

expressed aggression (Lawton & Nutter, 2002).

Research has also shown that the likelihood of aggressive driving behaviour can

be exacerbated by other risk-taking behaviours such as alcohol/drug driving by reducing

driver inhibitions and the subsequent desire/need to conform to cultural norms that

dictate appropriate on-road behaviour (Mann, Smart, Stoduto, Adlaf, & Ialomiteanu,

2003; James & Nahl, 2000). In light of the foregoing findings, the early stage of this

research will focus on the involvement of young drivers, as a high-risk group for

aggressive driving behaviour.


1.5 Research Objectives and Rationale

The foregoing overview suggests a need for further research into aggressive

driving as a phenomenon, and the need to examine why some drivers are more likely to

engage in such behaviours than others. Questions remain concerning what should be

classed as aggressive driving, the nature of aggressive driving behaviour and which

particular behaviours should be considered to constitute acts of aggressive driving. In

addition to exploring some of the contextual factors that contribute to aggressive driving,

this research will emphasise influences outside the confines of the on-road, or contextual

environment. For instance, perhaps there are other experiential or person-related

differences between drivers that may contribute to aggressive driving. For example, the

first study will investigate young driver person-related characteristics and how these off-

road influences may influence their on-road driving behaviour. Perhaps, partly as a

function of where and when they drive, it would seem logical that the on-road contextual

characteristics (or triggers) young drivers are exposed to would not differ greatly from

those that trigger aggressive behaviour in older drivers.

This research will examine aggressive driving behaviours from both the

perspective of high-risk groups and the general driving population. The principle

research objectives of the research program are to:

1. Integrate relevant theory from human aggression studies and traffic psychology

to more fully understand aggressive driving behaviour.

This research objective will be addressed progressively in each of the studies. As

highlighted above, it is timely to examine this phenomenon from the perspective of a

wide range of psychological aggression theories. The GAM (Anderson & Bushman,

2002), which contains a number of potentially relevant theories, will be used to

guide the examination of the phenomenon in each of the studies (refer to Section 1.3

and Chapter Three).

2. Explore the scope and nature of aggressive driving.

Little research has been conducted into the nature and extent of aggressive driving in

Australia (DCPC, 2005; AAMI, 2002, 2003). For instance, what behaviours do

Queensland drivers believe constitute aggressive driving? How common are these

behaviours and do they all constitute the same level of risk?


3. Examine the contribution of person-related and contextual factors to aggressive

driving.

As outlined in Section 1.2 it is clear that person-related and contextual factors, or a

combination of them, contribute to the likelihood of aggressive driving behaviour.

However, do person-related characteristics have a greater influence on the likelihood

of adopting aggressive driving behaviour than contextual factors? In particular, what

factors can be associated with an increased likelihood of expressing aggression on

the roads.

4. Examine whether some drivers are more likely to engage in aggressive driving

than other drivers.

In consideration of the influence of certain risk factors upon the development of

aggressive, person-related tendencies, and the increasing number of psychological

interventions that are being recommended for court referred aggressive drivers, it is

appropriate to examine the characteristics of high-risk drivers. Are drivers more

likely to engage in aggressive driving identifiable by any particular driving-related or

person-related characteristics?

5. Inform the development of more effective educational and rehabilitation

initiatives designed to reduce the incidence of aggressive driving.

By addressing the foregoing research objectives it is anticipated that the research

will contribute to a fuller understanding of the nature of aggressive driving and the

psychological processes involved. It is anticipated that these findings will contribute

to the development of appropriate educational and rehabilitation initiatives that have

been informed by theory-based research.

1.6 Scope of this Research

The following is a brief outline of the remaining issues concerning the scope of this

research. As noted above, the research examines aggressive driving behaviours from the

perspective of Queensland drivers, both high-risk drivers and the general driving

population. Study One focuses on young drivers (17–24 years of age) who have

previously been identified as being over-represented in aggressive driving incidents.

Study Two adopts a more general perspective examining aggressive driving among a

general sample of drivers. However, a specific high-risk subgroup of drivers is


identified within the sample, who are prepared to engage in more extreme acts of driver

aggression. The theme of high-risk offenders is further examined in Study Three, which

reports an in-depth analysis of ten self-confessed hostile drivers. It should be noted that

all three studies were conducted in the State of Queensland. However, the findings

should remain generalisable to the driving populations in other Australian states, due to

the random selection of participants and the substantial cultural similarities between

states.

1.7 Methodological Approaches Used

This research will utilise a wide range of psychological and traffic-related research

methods that are both qualitative and quantitative in nature. Study One utilises a

qualitative approach to explore the aggressive driving experiences and perceptions of

young drivers. Focus groups were used to facilitate this process. In a quantitative

approach, Study Two uses self-report measures to explore aggressive driving from

within a psychological framework based on the literature review and Study One

findings. Additionally, Study Two explores the psychosocial differences between

younger and older drivers. The study also tested for differences between low and high

anger drivers in order to examine the characteristics of the potentially hostile aggressive

driver. Finally, contingent upon the findings of Study Two, Study Three was designed

to assist in the exploration of self-confessed highly aggressive drivers capable of

extremely hostile on-road behaviour. As noted above, using a case study approach this

study examined more intimate person-related details of the self-reported, highly

aggressive driver.

1.8 Outline of the Thesis

Chapter Two provides a foundation for the program of research by proposing a

‘working’ definition of aggressive driving to guide the research and reviewing the

empirical evidence relating to the phenomenon of aggressive driving, with specific

reference to high-risk groups, such as young drivers. This chapter then reviews the key

contextual and person-related factors that have been empirically found to influence the

likelihood of aggressive driving behaviour, though it is acknowledged that greater

emphasis is given to the relevant person-related characteristics. A brief review of the


psychology of younger drivers will be conducted with specific reference to previous

studies concerning young driver behaviours.

Chapter Three reviews current theories of human aggression and their potential

significance to aggressive driving behaviours. In particular, the General Aggression

Model (GAM) is examined (Anderson & Bushman, 2002) as the aggression theories

contained within it appear to provide insight to the processes involved in aggressive

driving. Consideration of these theories will be guided by their influence upon person-

related contributing factors to aggressive driving outcomes. In keeping with previous

research, this thesis will focus on the trait and state person-related characteristics of the

younger driving population. Consistent with the psychosocial approach to this research,

this chapter will also provide a review of key developmental risk factors for aggression.

Chapter Four details Study One which is an investigation into the nature of

aggressive driving from the perspective of young drivers aged 17–24 years. This

qualitative study utilised focus groups with young drivers to explore the theoretical

issues highlighted by the review of relevant human aggression theories, particularly the

GAM (Anderson & Bushman, 2002). Based upon these theoretical considerations and

the findings of this study, a psychosocial framework for aggressive driving is proposed.

Chapter Five is a quantitative study assessing the validity of the proposed factors

considered psychologically relevant in aggressive driving behaviour. Additionally, the

data was used to compare young drivers with a cross section of the general driving

population. The close examination of a large age range of drivers will facilitate the age-

related incidence of such behaviour and give greater insight to the contributing

psychological and contextual factors involved in on-road aggression. From within the

chosen theoretical framework, the findings highlight differences between age groups

which may assist in explaining young driver overrepresentation in aggressive driving.

In an extension of the data collected in Study Two, Chapter Five will also detail

findings concerning those drivers that have been identified as potentially capable of

highly aggressive on-road behaviour. To further explore this issue, Study Three

examines the personal characteristics of self-reported highly aggressive drivers in

greater depth, utilising a qualitative case study approach (Chapter Six). Finally, Chapter


Seven provides a synthesis of the research across the three studies. Recommendations

for further research and the possible implications of the findings are discussed.

1.9 Chapter Summary

This chapter has outlined the rationale and structure underlying this thesis. To

date, aggressive driving research in Australia has been limited by its focus upon the

frequency and nature of acts of on-road aggression (VCCAV, 1999; AAMI, 2003)

reflecting a failure to investigate the issue in a holistic way. Although this information

has assisted researchers in understanding the scale of the problem, the underlying causes

and internal processes have not been thoroughly investigated in terms of an Australian

sample (AAMI, 2003; DCPC, 2005; VCCAV, 1999). Additionally, the literature review

indicates that no Australian studies have been conducted from within a framework of

psychological theory, which would assist in better understanding the fundamental

processes underpinning the phenomenon.


Chapter Two: Aggressive Driving Literature Review 2.1 Introduction............................................................................................................. 15 2.2 Defining Aggressive Driving ................................................................................. 15 2.2.1 The Distinction Between Aggressive Driving and ‘Road Rage’, and Other Ambiguities ................................................................................... 15 2.2.2 Emotional Catalysts for Aggressive Driving ........................................... 17 2.2.3 Aberrant Driving Behaviours to be Considered ...................................... 18 2.2.4 Distinguishing Victims from Perpetrators ............................................... 18 2.2.5 Recurring Themes ................................................................................... 19 2.2.5.1 Emotion ...................................................................................... 19 2.2.5.2 Behaviour ................................................................................... 19 2.2.5.3 Intentionality .............................................................................. 20 2.3 The Scope and Nature of Aggressive Driving ........................................................ 23 2.3.1 Prevalence of Aggressive Driving ............................................................ 23 2.3.1.1 International Studies ................................................................... 23 2.3.1.2 Australian Studies ...................................................................... 24 2.3.2 Types of Aggression on the Roads ........................................................... 25 2.4 Factors Contributing to Aggressive Driving........................................................... 27 2.4.1 Empirical Evidence .................................................................................. 27 2.4.2 Theoretical Perspective ............................................................................ 29 2.5 Person-Related Contributors to Aggressive Driving .............................................. 33 2.5.1 Age, Gender and Aggressive Driving ...................................................... 33 2.5.2 Personality and Psychopathology ............................................................. 34 2.5.3 Trait Aggression ....................................................................................... 37 2.5.4 Driving Anger ........................................................................................... 39 2.5.5 Impulsivity ................................................................................................ 41 2.5.6 Sensation-Seeking .................................................................................... 41 2.5.7 Self-Esteem............................................................................................... 42 2.5.8 Transfer of Stress to and from the On-Road Environment ....................... 43 2.5.8.1 The Experience of Stress on the Road........................................ 44 2.5.8.2 Effect of Gender and Age on the Experience of Stress .............. 45 2.5.8.3 Driver Trait Stress Measures ...................................................... 45 2.5.8.4 Individual Mood and Daily Hassles ........................................... 47 2.5.8.5 Life Event Stress ........................................................................ 48


2.5.8.6 Work Stress ................................................................................ 48 2.5.8.7 Fatigue ........................................................................................ 49 2.6 Situational Contributors to Aggressive Driving ..................................................... 49 2.6.1 On-Road Situational Factors .................................................................... 50 2.6.1.1 Type of Road .............................................................................. 50 2.6.1.2 Congestion .................................................................................. 51 2.6.1.3 Interim Summary ........................................................................ 52 2.7 Issues Specific to At-Risk Drivers .......................................................................... 53 2.7.1 Lifestyle .................................................................................................... 53 2.7.2 Education Attained ................................................................................... 54 2.7.3 Driving Experience ................................................................................... 54 2.7.4 Passenger Effect ....................................................................................... 55 2.7.5 Motivation ................................................................................................ 56 2.7.6 Drugs and Alcohol .................................................................................... 57 2.8 Focus of Emerging Interventions ............................................................................ 58 2.8.1 Coping Styles in General .......................................................................... 59 2.8.2 Driver Coping Strategies .......................................................................... 62 2.9 Research Questions ................................................................................................. 63 2.10 Chapter Summary ................................................................................................... 65


2.1 Introduction

This chapter integrates the existing literature concerning aggressive driving in

relation to drivers in general and high-risk groups such as young drivers. Consistent

with the objectives of this research, person-related and situational factors that may

influence the transfer of aggression to and from the road environment are also

emphasised.

For the purpose of the research it is necessary to determine a working definition of

aggressive driving. A review of the literature reveals little consensus regarding a

universal definition of aggressive driving. Some existing definitions have been

formulated in response to public demand for appropriate legislation governing

aggressive driving behaviours (Jarred, 2002; NSW Road Transport [Safety &

Management] Act 1999; Section 328A, Transport Operations [Road Use Management]

{TORUM} Act, 1995). Alternatively, some researchers have resisted formulating a

definition, as their main focus has been to understand the underlying processes involved

in specific aberrant driving behaviours. However, as this research examines the

phenomenon as a whole a working definition was considered necessary. As illustrated

in the following discussion, there is a range of considerations when determining what

behaviours constitute aggressive driving.

2.2 Defining Aggressive Driving

2.2.1 The Distinction Between Aggressive Driving and ‘Road Rage’, and Other

Ambiguities

Aggressive driving research is a complex issue hampered by many ambiguities.

The ambiguities are most apparent in the terminology used to describe the phenomenon.

‘Road rage’ is a term often used by both the media and the general population to

describe a wide variety of on-road incidents that involve acts of aggression or violence.

However, the media often focus on the more extreme cases of on-road violence, some of

which arguably represent cases of assault that happen to occur on the road (Elliott,

1999). As such, while the terms ‘road rage’ and ‘aggressive driving’ are often used

interchangeably by the media, and hence the general community, the term ‘road rage’ is

generally associated with more extreme acts of on-road violence.


In contrast, traffic researchers have generally adopted a broader perspective to

explaining on-road aggression, which has involved focusing on both milder and more

severe acts of aggression (Deffenbacher, Oetting, & Lynch, 1994; Elliott, 1999;

Harding, Morgan, Indermau, Ferrante, & Blagg, 1998; Lajunen, Parker, & Stradling,

1999). Nonetheless, the terms ‘road rage’ and ‘aggressive driving’ are sometimes used

interchangeably by road safety researchers. For example, a recent meta-analysis of

aggressive driving research suggests that many on-road behaviours relevant to

aggressive driving have been labelled in the literature as “risky, aggressive, or road

rage” (Dula & Geller, 2003; Tasca, 2001).

A common perspective among many traffic researchers is that aggressive driving

behaviour occurs on a continuum ranging from relatively benign acts of ‘swearing under

one’s breath’ to open, deliberate acts of physical violence (Lajunen & Parker, 2001;

Shinar, 1998). Among these researchers, the term ‘road rage’ is sometimes used to

embody the more extreme acts of on-road aggression on this continuum (e.g. Shinar,

1998). However, other researchers (e.g. Elliott, 1999) have argued that the term ‘road

rage’ adds little to the understanding of the phenomenon and should be abandoned, or at

least reserved for describing acts of assault that happen to occur on the road.

Over and above Elliott’s (1999) concerns about the use of the term ‘road rage’, it

would appear important to acknowledge that aggressive driving behaviours can vary in

severity. Hence, this program of research will explore the extent to which aggressive

driving can be conceptualised as a continuum of behaviours. However, to avoid

confusion, the term ‘aggressive driving’, rather than ‘road rage’, will be used in a

generic sense in this thesis to describe the full range of on-road behaviours that have

typically been identified as aggressive in the literature. Furthermore, it should be noted

that it is not an aim of this research to determine whether there is a conceptually distinct

class of aggressive on-road behaviours that warrant being referred to as ‘road rage’.

Rather, ‘road rage’ will be simply treated in this thesis as a label that is applied by some

researchers to either aggressive driving as a whole, or a particular class of aggressive

driving behaviours.

A further ambiguity that has hampered research in this area has been the

tendency of some researchers to define aggressive driving in terms of a list of


behaviours that are deemed to be aggressive, rather than develop a distinct conceptual

definition of the phenomenon. Such an approach is inherently circular in nature,

contributing to the inconsistent operationalisation of the concept (Deffenbacher, Oetting,

& Lynch, 1994; Mathews, Dorn, & Glendon, 1991; Parker, Lajunen, & Stradling,

1998).

Finally, there has historically been a wide range of variability in the actual

definitions of aggressive driving that have been proposed by different researchers

(NHTSA, 2002; Elliott, 1999; Goehring, 2000; James & Nahl, 2000 Jarred, 2002). The

following examples illustrate the diversity of current definitions:

“aggressive driving…as the operation of a motor vehicle in a manner which

endangers or is likely to endanger persons or property.”(NHTSA, 2002)

“aggressive driving…the operation of a motor vehicle without regard to

others’ safety.”(AAA, 2008)

“aggressive driving is…an incident in which an angry or impatient motorist or

passenger intentionally injures or kills another motorist, passenger or

pedestrian…or…intentionally drives his or her vehicle into a building or other

structure or property…in response to a traffic dispute, altercation, or

grievance.”(Mizell, 1997, p. 5)

“aggressive driving…a syndrome of frustration-driven behaviours which are

manifested in…inconsiderateness towards or annoyance of other drivers and,

deliberate dangerous driving to save time at the expense of others.”(Shinar, 1998, p.

139)

Together, the above ambiguities have plagued much of the aggressive driving

research undertaken to date. Accordingly, the following sections will review some of

the key conceptual themes characterising previous definitions of aggressive driving, in

order to identify a working, provisional definition to underpin this program of research.

2.2.2 Emotional Catalysts for Aggressive Driving

Most aggressive driving research has adopted the view that immediately

preceding the expression of on-road aggression, an individual must experience a

negative emotional state, such as high levels of frustration or anger (Deffenbacher et al.,

1994; Lajunen & Parker, 2001; Shinar, 1998). Aggression research indicates that


‘frustration’ increases levels of arousal, possibly energising an individual’s response to a

situation (Geen, 1990). Whether or not the resultant road behaviour is outwardly hostile

or instrumental is believed to be dependent on the individual’s trait/state predisposition

for aggression (Lajunen & Parker, 2001). In addition to frustration and aggression,

perhaps it should also be considered that behaviours that may be interpreted as

aggressive may also result from heightened arousal as a result of other emotions such as

excitation (Zillman, 1988). For example, young drivers may experience heightened

arousal as a result of ‘hooning’ or driving with peers. Further, researchers have also

identified perceived ‘threat’ to one’s safety or wellbeing as an emotional catalyst for

aggression (Berkowitz, 1993).

Therefore, due consideration needs to be given to the ‘emotion’ and ‘arousal’

levels experienced by drivers. Furthermore, there is a need to investigate on and off-

road sources that may trigger changes in emotional and arousal levels culminating in the

potential to influence the likelihood of on-road aggression.

2.2.3 Aberrant Driving Behaviours to be Considered

Within some definitions of aggressive driving, there is a trend to include aberrant

driving behaviours that can directly or indirectly endanger other road users, such as

speeding (Beirness, Simpson, Mayhew, & Pak, 2001; Goehring, 2000; Shinar, 1998).

Traditionally, behaviours such as speeding and ‘hooning’ were studied in terms of thrill-

seeking and/or risk-taking behaviours, however, little attention has been paid to the role

of the cognitive/emotional processes associated with these behaviours and the

subsequent emotions experienced should these tendencies be blocked/impeded from

expression on the road. It is reasonable to anticipate that should these behaviours be

blocked, frustration/anger may result (Dollard, Doob, Mowrer, Miller & Sears, 1939).

Hence, particularly for young drivers, these on-road behaviours may contribute to

society’s perception of them as highly aggressive. Consequently, this thesis will initially

include such behaviours as potentially ‘aggressive’.

2.2.4 Distinguishing Victims from Perpetrators

In the study of aggressive driving, it is often difficult to distinguish the

perpetrators from the victims (VCCAV, 1999). In part, this is due to the desire to

preserve a positive image of oneself: it being easier to accuse, or blame others for


aggressive incidents than accept responsibility for our own aggressive contribution

(Lamb, 1996). Instrumental on-road behaviours can also be misinterpreted by other road

users as aggressive. Indeed, attempting to merge onto a freeway may require decisive

action, however, this behaviour is not necessarily motivated by ‘anger’. In this instance,

if the attempt to merge is interpreted as ‘cutting-off’ by another road user, an on-road

incident may escalate in a ‘tit for tat’ manner. This example highlights the difficulties

inherent in distinguishing victims from perpetrators and also illustrates the difficulty of

distinguishing acts of intentional behaviour from mere on-road errors. It also illustrates

the need for behaviours such as speeding to be considered in aggressive driving research

due to its direct influence upon other subsequent road behaviours, such as weaving in

and out of traffic as a result of speeding.

2.2.5 Recurring Themes

Despite differences in definitions, a recent meta-review of aggressive driving

research (Dula & Geller, 2003) identified three common themes characterising previous

attempts at a definition of aggressive driving: emotion, behaviour and intention.

2.2.5.1 Emotion

Several researchers suggest that aggressive driving behaviour always appears to

be emotion driven, involving negative emotions such as anger, rage, sadness or

discontent (Dula & Geller, 2003; Tasca, 2001). Shinar’s (2001) Frustration-Aggression

model of aggressive driving also suggests that aggressive driving behaviour is driven by

frustration and/or anger. However, both views do not acknowledge that other emotions

may also lead to aggressive acts (Zillmann, 1971). For example, younger drivers in

particular may at times drive at higher speeds for exhilaration, engaging in on-road

behaviours that may be considered aggressive by others. Therefore, whilst negative

emotion is commonly associated with aggressive driving behaviour, this is an issue

requiring further investigation.

2.2.5.2 Behaviour

Traditionally, a wide range of behaviours has been considered to be

representative of aggressive driving research, including tailgating, weaving in and out of

traffic, cutting-off other vehicles, vehicle following and horn-honking. In light of the

commonalities identified across aggressive driving research, Dula and Geller (2003)


identified a range of behaviours to be considered in defining ‘aggressive driving’. They

propose that certain on-road ‘risk-taking’ behaviours as defined by other researchers

(Arnett, Offer, & Fine, 1997; Jonah, 1997; Smith & Heckert, 1998), not only include

behaviours such as speeding and tailgating, but also include lapses in concentration,

using a mobile phone, eating, drinking or adjusting a stereo whilst driving (Dula &

Geller, 2003). Tasca (2001), however, asserts the importance of including all on-road

risk-taking behaviours when discussing aggressive driving, but only when such

behaviours are combined with emotion and intention as then they have the potential to

‘endanger others’. However, Dula & Geller (2003) assert that all such ‘risky’

behaviours may occur in the absence of negative emotion or the ‘intent’ to harm another

driver and therefore cannot be included in aggressive driving behaviours (Dula & Geller,

2003). Although lapses in concentration and attendance to other tasks such as adjusting

one’s radio could hardly be considered aggressive, it is arguable that there are some

risky driving behaviours that need to be considered within the domain of aggressive

driving. For example, given intentionality and emotion, speeding, tailgating and

weaving through traffic may be considered aggressive as these behaviours may be used

deliberately to gain an advantage over, or to intimidate, other road users.

Further, Mizell’s (1997) research found that the precursory events associated

with aggressive driving incidents often appeared rather trivial. The disputes escalated

to extreme levels of aggressive driving over such issues as car parking spaces, cutting

off other drivers, minor collisions, obscene gestures, loud music, slow driving, and

tailgating (Mizell, 1997). The findings highlight the potential for benign road incidents

to escalate into violence, indicating that perhaps the experience of high level anger is not

necessarily the only precursor emotion to aggressive driving behaviour. Mizell (1997)

noted also that the disputes were rarely the result of one event, but rather an

accumulation of factors that increase the likelihood of an aggressive act. Therefore, the

context in which such behaviours occur appears important if it is to be considered

aggressive driving behaviour.

2.2.5.3 Intentionality

Under existing legislation in Queensland, aberrant/risky driving behaviours, in

general, need not be purposefully or deliberately aimed at another specific driver in


order to be considered dangerous on-road behaviour (Jarred, 2002). Consistent with this

thinking, researchers argued that aggressive driving is more closely associated with risk-

taking behaviour regardless of whether it is intentionally perpetrated or not

(Deffenbacher, Kemper, & Richards, 2007). This position appears to be based on the

view that certain risk-taking behaviours are generally considered by the community and

law enforcement agencies to be inherently aggressive, regardless of the ‘intent’ or

desired outcome of the driver. These behaviours would include speeding, tailgating, or

weaving in and out of traffic. However, other researchers have argued that an on-road

behaviour should only be classed as aggressive if it is perpetrated with the ‘intent’ to

physically or psychological harm another driver (Dula & Geller, 2003; Mizell, 1997;

Tasca, 2001). In this regard, a behaviour like tailgating would only be categorised as

aggressive if it was intended to cause some form of discomfort or distress to another

driver. Tailgating for other reasons would be better viewed as an example of careless

driving or risk-taking. In effect, this position holds that it is the intentions of the

perpetrator rather than the perceptions of the victim that most reliably and objectively

define aggressive driving. Consequently, the inclusion of ‘intent’ within a definition of

aggressive driving more clearly provides a means to distinguish what types of risk-

taking behaviours constitute examples of aggressive driving (Dula & Geller, 2003;

Tasca, 2001).

Once the central role of intent in aggressive driving is acknowledged, it becomes

evident that it and risk-taking are arguably overlapping concepts as shown in Figure 2.1.

While some aggressive behaviours (such as flashing lights and horn-honking) would not

be generally classed as risk-taking, others such as tailgating do increase crash risk.

However, those risk-taking behaviours which are not intended to harm other drivers,

such as using a hand-held phone, should arguably not be classed as aggressive.

Similarly, tailgating due to carelessness or inattention would represent an example of

risk-taking behaviour, but not an aggressive driving behaviour.


Figure 2.1 Relationship of risky driving behaviours to aggressive driving behaviours

In keeping with the foregoing considerations, this research will therefore utilise a

‘provisional’ definition of aggressive driving that includes the elements of emotion,

behaviour and intent suggested by the foregoing research (Dula & Geller, 2003;

Tasca, 2001). This ‘provisional’ definition is:

“Aggressive driving is any on-road behaviour adopted by a driver that is

intended to cause physical or psychological harm to another road user and is

associated with feelings of frustration, anger or threat.”

It should be noted that the concept of ‘harm’ inherent in the definition will be

interpreted in a broad manner ranging from attempts to cause discomfort to other drivers

through to more serious distress or physical harm.

Being consistent with available literature, this definition facilitates the scientific

investigation of the phenomenon of aggressive driving (Dula & Geller, 2003; Tasca,

2001). Additionally, it allows the concept of aggressive driving to be investigated more

fully from the perspective of popular perceptions of the phenomenon, which may allow

a more practical understanding of the behaviour. As a ‘provisional’ definition, the above

definition of aggressive driving will be used to guide the program of research and to

formulate relevant research questions and hypotheses. However, the final acceptability

of the definition will be subject to the findings of the research.

On-Road Risk-Taking Behaviour

Aggressive Driving

Behaviours that are intended to negatively impact on other road users.

Behaviours that increase the crash risk of drivers.


2.3 The Scope and Nature of Aggressive Driving

2.3.1 Prevalence of Aggressive Driving

The following discussion of international and Australian prevalence rates of

aggressive driving behaviour does not utilise the above provisional definition of

aggressive driving, rather it assumes the various definitions adopted by the original

researchers. The measure of actual prevalence rates of aggressive driving in Australia

and overseas has been problematic in that there are a large number of variations in the

definition used. Accurate measure has also been thwarted by the number of drivers that

fail to report all but the most serious of incidents. Therefore, Section 2.3.1.1 and 2.3.1.2

below combine the discussion of actual prevalence rates with perceived rates. While the

following review will utilise the definitions adopted in each particular study, they will be

considered relative to the provisional definition provided at Section 2.2.5.3.

2.3.1.1 International Studies

In a large study by the American Automobile Association Foundation for Traffic

Safety (Mizell, 1997), 10,037 separate incidents of aggressive driving reported in police

records and newspaper articles between 1990–1996 were examined. Review of the case

data revealed that 12,610 people were injured and 218 killed, highlighting the potential

danger of aggressive driving.

Additionally, in 2000, a Traffic Injury Research Foundation survey of 1,207

Canadian drivers revealed that 65% of participants perceived aggressive driving to be a

serious problem (Beirness et al, 2001). This project aimed to identify the road safety

issues which most concerned Canadians and participants were queried on their

observation of aggressive on-road behaviours. The aggressive behaviours most

frequently observed were speeding, tailgating, failing to signal, weaving in traffic,

unsafe passing, too slow in a fast lane, failure to stop, and running red lights (Beirness et

al., 2001).

Similarly, a survey of 6,000 American drivers conducted by the National

Highway Traffic Safety Administration (2002) explored the incidence of unsafe driving

practices. In the survey, 62% of participants reported that the behaviour of another

driver had posed a threat to their safety in the last 12 months. The participants also


identified certain road behaviours that they considered unsafe or aggressive: cutting-in,

speeding, and tailgating.

2.3.1.2 Australian Studies

In Australia, a police database search of 797 driving incidents deemed to be

aggressive by Harding and colleagues (1998) reported a steady increase in the number of

aggressive driving incidents reported over the period 1991–1995. Subsequent

aggressive driving research conducted by Elliott (1999) acknowledged the existence of

‘road violence’ in Australia, but suggested that so few incidents result in crash

involvement, injury or death, that little can be achieved by paying undue attention to

such behaviour. Indeed, Elliott (1999) suggests that part of the solution for ‘road rage’

is to put the problem back into perspective by reducing the media attention given to the

relatively few incidents of ‘road violence’ that are intentionally perpetrated. He also

maintains that ‘road rage’ is a product of pre-existing criminal tendencies in an

individual.

Distinguishing between on-road violence and lesser acts of hostility or selfish-

driving, the Victorian DCPC conducted an on-line survey of 85 instances of aggressive

driving (DCPC, 2005). Of the recounted instances, 15 individuals (18%) were able to

recall instances of road violence, however, the majority reported lesser acts. In contrast,

another Victorian study suggested that ‘road rage’ (or aggressive driving) behaviour is

indeed a significant problem on Australian roads, at least in terms of public perceptions

(VCCAV, 1999). The study found that 52% of the 801 participants surveyed believed

that the level of aggressive driving had increased over the last 12 months. Almost half

of the male participants reported that they would be prepared to shout abuse at another

driver, gesticulate at another driver (examples of interpersonal aggression), and drive

more slowly to deliberately antagonise the other driver. In comparison, female drivers

aged 25–34 years were found to be significantly more likely than the population as a

whole to perpetrate mild ‘road rage’ acts. Presented in the order of ‘most commonly’ to

‘least commonly’ adopted, these behaviours were: prolonged horn honking, flicking of

lights on and off, shouting abuse, making obscene gestures, braking or slowing

suddenly, and tailgating.


Overall, the Australian studies suggest that the aggressive driving phenomenon is

on the increase, despite the fact that these studies used varying definitions of aggressive

driving which either include or preclude certain behaviours which may otherwise be

seen as risk-taking and therefore unintentionally directed at other drivers (AAMI, 2001,

2002, 2003; Harding et al., 1998 VCCAV, 1999). The Australian findings also appear to

be consistent with aggressive driving research conducted in other developed countries

(Hennessy & Wiesenthal, 1997; Hennessy & Wiesenthal, 1999; Lajunen, Parker, &

Summala, 1999; NHTSA, 2002; Shinar, 1997) . Further, though the number and

frequency of extreme cases of intentional acts of on-road aggression may be minimal

among the general driving population, the subsequent consequences can be severe.

Extreme instances of on-road aggression can result in physical and/or psychological

harm as well as property damage (Beirness et al., 2001; Mizell, 1997). Therefore, in

light of the perceived increase in societal frustrations and ever-increasing numbers of

road users, it would be prudent for traffic researchers to adopt a pro-active role in

determining the extent and causes of aggressive driving. Moreover, as Australian

drivers have indicated a perceived increase in aggressive driving behaviour, it is

necessary for research to continue, with a view to understanding the relevant

psychological processes involved. A better understanding of these processes would

assist in the development of evidence-based countermeasures.

2.3.2 Types of Aggression on the Roads

As previously stated, behaviours that have been commonly labelled ‘aggressive

driving’ appear to occur on a continuum from swearing under one’s breath to physical

assault (Lajunen & Parker, 2001). Those that perpetrate acts of aggressive driving not

only use interpersonal aggression to manipulate the driving behaviour of others, they

also frequently use their vehicles to express aggression by using intimidatory tactics to

manipulate the driving behaviour of other road users. For example, tailgating could be

viewed as an intimidating use of the vehicle that also has the potential for serious

consequences such as physical damage to person or property and/or psychological

damage.

As a consequence of the complexity and range of behaviours involved in

aggressive driving, some traffic researchers have chosen to differentiate between


instrumental and hostile aggression (Lajunen & Parker, 2001; Shinar, 1998). Hostile

aggression is defined as behaviour that is primarily and purposefully aimed at physically

or psychologically harming the source of frustration. For example, verbal abuse,

physical attack and hand gestures. Instrumental aggression is considered to be driving

behaviour that is intended to assist a driver to move ahead or overcome the source of

frustration, e.g. horn honking, weaving, speeding, running red lights and tailgating

(Shinar, 1998). However, as previously discussed in Section 2.2.5 arguably these

instrumental behaviours can at times be perceived as hostile by other road users,

sometimes resulting in an escalation of the on-road encounter to severe consequences

(VCCAV, 1999; Yagil, 2001). Indeed, it appears that when considering aggressive

driving behaviours, even benign behaviours may have potentially severe consequences.

In an attempt to align the expression of aggression with existing psychological

theory (Berkowitz, 1990; Berkowitz, 1993) and to assess whether drivers actually do

become more aggressive whilst in their vehicles, recent road research has distinguished

between outward, displaced and suppressed aggression (Lawton & Nutter, 2002). For

these researchers, outward aggression is the overt behavioural expression of aggression

in the on-road environment; displaced aggression involves displacing feelings of

frustration/anger to the off-road environment; whilst suppressed aggression involves the

absence of behavioural expression either on or off-road. It was found that drivers were

no more likely to experience anger whilst driving than in other situations, but they were

significantly more likely to report the displacement of their anger in a driving situation

(Lawton & Nutter, 2002). Additionally, these researchers found a significant difference

between males and females in the types of on-road aggression adopted. Females were

more likely to adopt displaced or suppressed levels of expression, whilst males were

found to report higher levels of outwardly expressed aggression than females (Lawton &

Nutter, 2002).

In this thesis, the importance of distinguishing hostile on-road behaviours from

instrumental behaviours is acknowledged. However, as one of the aims of this thesis

will be to examine aggressive driving as it is experienced by drivers, particularly

younger and other at-risk ones, and also to consider the possible transference of anger to

and from the road environment, perhaps making the distinction between outward,


suppressed or displaced aggressive expression, will prove useful, particularly in Study

One.

2.4 Factors Contributing to Aggressive Driving

2.4.1 Empirical Evidence

Traffic researchers have compiled extensive lists of factors that influence on-

road driving behaviour in general, illustrated in Figure 2.1 (Lonero & Clinton, 1998).

Although, this figure is not specific to aggressive driving behaviours, it illustrates the

multiplicity and complexity of factors that contribute to on-road driver behaviour.

Indeed, many of the factors cited below have been identified as potential contributors to

aggressive driving, including congestion, psychopathology, education, peer pressure,

driving experience, time pressure and near misses/conflicts.

Specific to aggressive driving, the discussion of potential contributing factors has

tended to be guided by two broad categories: person-related and contextual factors

(DCPC, 2005; Shinar, 1998). Comparatively little research has been conducted into

contextual factors that contribute to aggressive driving. However, existing research has

revealed that other factors such as the age and gender of the ‘other driver’, time pressure,

congestion, and any resultant on-road behaviours or perceived delays may influence

feelings of anger and the likelihood of aggressive driving behaviour (Lajunen & Parker,

2001; O’Brien, Tay & Watson, 2005; Underwood, Chapman, Wright & Crundall,

1999). This is not intended to undermine the potential importance of contextual factors

in aggressive driving incidents, as will be highlighted below.

Reflecting on the complexity of Figure 2.1, perhaps this apparent gap in research

is because there appears to be an enormous number of factors that may provide the right

context for aggressive behavioural responses, particularly among those drivers that have

a higher person-related disposition for on-road aggression. Therefore, situational factors

are not the primary focus of this research. Indeed, the person-related characteristics of

high-risk driver groups for on-road aggression will be emphasised. Such an emphasis

should serve to deepen our understanding of the nature of aggressive driving behaviour.


Figure 2.2 Conditions influencing driver behaviour (Lonero & Clinton, 1998, p.6)

The transfer of aggression to or from the road environment is believed to occur

via the emotional and physiological changes associated with ‘stress’ (Simon & Corbett,

1996; Stokols & Novaco, 1981). As such changes are generated and manifested within

an individual, the discussion of person-related factors will emphasise the ‘trait’ or ‘state’

related stressors that contribute to the experience of stress whilst driving. Trait person-

related factors are relatively enduring, personal characteristics that an individual brings

to any situation. Traits have long been associated with aggressive behavioural outcomes

in interpersonal relationships, and also in aggressive driving research (O’Connor,

Archer, & Wu, 2001; Deffenbacher, Oetting, & Lynch, 1994). ‘State’ person-related

Current Driving

Behaviour

Traffic Congestion Frustration/ Aggression

Psychopathology

Legislation

Enforcement

Deterrent Threat Task Conflicts Distractions

Impairment

Fatigue Attention/ Alertness

Near Misses/ Conflicts

Other Drivers

Feedback

Information Processing Skills

Human Limits

Vehicle handling

Time Pressure

Trip Purpose

Economic Cycle

Value of Present Time

Driving Culture Mobility/Growth Broad Societal

Concerns

Conservation Media/ Pop Culture

Commercial Advertising Motor sport

Fun/Adventure Marketing

Habits

Experience

Training

Risk Acceptance

Value of Future Time

Family Pressure

Peer Pressure Observed Models

Informal Social Norms

Thrill Seeking

Boredom Stimulus Needs

Education

Publicity/News

Knowledge


factors are those factors that affect an individual’s current mood or emotional state, and

are relatively less enduring and short lived.

Further to the aims of this research, the review will frequently refer to the driving

behaviour of at-risk drivers in general, who appear to be more involved in aggressive

driving incidents and the associated consequences. It is widely accepted that although it

is not axiomatic for aggressive driving to equate to road crashes, many of the behaviours

widely accepted as aggressive in nature contribute to them (Dahlen, Martin, Ragan, &

Kuhlman, 2005; Underwood, Chapman, Wright, & Crundall, 1999; Wells-Parker,

Ceminsky, Hallberg, Snow, Dunaway, Guiling, Williams, & Anderson, 2002).

Therefore, some reference will also be made to aberrant driving behaviours associated

with aggressive driving and crash risk.

2.4.2 Theoretical Perspective

As stated in Chapter One, this literature review revealed only one comprehensive

model of aggressive driving based on psychological theory. In 1998, David Shinar

proposed a multi-factor approach to aggressive driving utilising the frustration-

aggression hypothesis (Dollard et al., 1939 – see Section 3.3.1), depicted in Figure 2.3.

In this model, Shinar (1998) proposes that frustrating road situations, such as

congestion or delays, mediated by an individual’s trait predisposition for aggression,

contribute to a driver’s aggressive disposition. In accordance with frustration-aggression

theory congestion or delays are ‘goal blocking’, interfering with driving progress. In

response to goal blocking, drivers experience an increase in frustration that in turn

lowers the driver’s aggression threshold increasing the likelihood of road aggression

(Shinar, 1998). Whether aggressive driving is displayed on the road or not, is influenced

by the driver’s interpretation of the situation, influenced by such things as ‘cultural

norms’ (Gnepp, 1979; Shinar, 1998). In the absence of aggressive driving outcomes, it

is believed that the expression of aggression is displaced to a later point in time (Lawton

& Nutter, 2002). For instance, such aggression could be displaced into the social or

work environment. However, the same research has also highlighted that

frustration/aggression may be suppressed never to manifest in an aggressive act. The

ability to suppress such emotion implies some internalised control or ability to cope with

frustration and/or anger. This will be discussed in more detail in Chapter Three.


According to Berkowitz (1993), however, the amount of anger experienced in a

frustrating situation not only depends on the individual interpretation of the situation but

the characteristics of the situation itself. Shinar (1998) believes the perceived recent

FRUSTRATING SITUATION - Congestion - Delays

PERSONALITY (Trait Factors)

- Hostility - Extroversion - Type A/B

ENVIRONMENT (Facilitating Factors)

- Anonymity - Legitimacy - Poor Communications

AGGRESSIVE DISPOSITION

AGGRESSION POSSIBLE? - Cultural norms - Enforcement

DISPLACED AGGRESSION

PATH TO GOAL

BLOCKED?

HOSTILE AGGRESSION - Verbal abuse - Physical attack - Hand gestures - Horn honking

INSTRUMENTAL AGGRESSION - Weaving - Running red lights - Tailgating - Horn honking

YES NO

NO

YES

Figure 2.3 Frustration-Aggression Model of Aggressive Driving (Shinar, 1998, p.140)


increases in aggressive driving incidents in general may not be due to a surge in the

number of aggressive drivers, but rather to an increase in ‘societal frustrations’.

Specifically, increasing levels of congestion on the roads and pressure for the greater

economic use of time may be increasing societal frustrations (Connell & Joint, 1996;

Mizell, 1997; Shinar, 1998). Such frustrations lower the aggression threshold for the

general population, making ordinary people more likely to bring an aggressive

predisposition to the road environment (Shinar, 1998). Therefore, part of the appeal of

Shinar’s model is its capacity to explain the ‘little bit of road-rage in all of us’, which

has the potential for severe consequences (notwithstanding the distinction made by some

between ‘road rage’ and aggressive driving – see Section 2.2.1).

As stated in Section 2.3.2, the types of aggressive behaviours that may result

from frustrating or anger-provoking on-road events appear to range from relatively

benign acts of swearing under one’s breath to violent acts of physical harm to person or

property. Whilst Shinar proposes that aggressive driving behaviours represent a

continuum ranging from the less severe behaviours to the more severe, he suggests that

those at the less severe end are essentially instrumental in nature and those at the more

severe end are hostile in nature. Instrumental aggression is considered to be all driving

behaviour which is intended to assist the aggressor to move ahead or overcome the

source of frustration or ‘block’, e.g. horn honking, weaving, running red lights and

tailgating. Hostile aggression is defined as that behaviour which is primarily and

purposefully aimed at harming the source of frustration, physically or psychologically,

e.g. verbal abuse, physical attack and hand gestures (Shinar, 1998). However, perhaps

even the instrumental behaviour can be misinterpreted as hostile and escalate to a more

severe road incident (VCCAV, 1999; Yagil, 2001). Importantly, this dichotomous

definition of on-road aggression implies that engaging in either type of behaviour serves

a purpose or function for a driver. Therefore, this thesis will examine in greater detail

the function or purpose served by engaging in mild to extreme aggressive driving

behaviours.

Within Shinar’s (1998) model the type of aggressive behaviour displayed is

influenced by the level of frustration experienced (Dollard et al., 1939); the perceived

penalty for the expression of aggressive driving (Dollard et al., 1939; Berkowitz, 1988);


and the legitimacy of the frustrator (Dollard et al., 1939). The level of aggression

displayed varies directly with the level of frustration experienced which is dependent on

the level of interference with the frustrated response and the frequency of the frustration

(Dollard et al., 1939). The perceived penalty for expression of aggression on the roads

is related to the inhibition of aggressive acts (Dollard et al., 1939). For example, the

presence of road-side police may deter the majority of drivers from the expression of

aggression on the roads (Holland & Connor, 1996). Finally, when a frustrator is

perceived as ‘unjustified’, an aggressive outcome not only becomes more probable, but

the resultant aggression appears to increase in intensity (Anderson & Dill, 1995;

Berkowitz, 1988; Dollard et al., 1939).

In contrast to Shinar’s model of frustration-aggression on the road, Berkowitz

(1993) maintained that aggression is not always the result of frustrations, rather

aggression is only evident when the frustration or an aversive event is ‘unpleasant

enough’ to produce negative effect, such as ‘anger’. Aggressive driving behaviour,

therefore, only manifests if a frustrating road event provokes ‘intense’ emotion, namely

‘anger’ (Berkowitz, 1993). Further, despite multiple frustrations and intensity of

emotions that can be generated by a road incident, Berkowitz and other researchers

continue to suggest that aggressive driving behaviour may not necessarily result

(Berkowitz, 1993; Lajunen & Parker, 2001; Lajunen, Parker, & Summala, 1999).

Consequently, in keeping with the Berkowitz’ (1993) reformulation of the original

frustration-aggression hypothesis, perhaps it is the cumulative effect of multiple factors

known to affect feelings of anger on the roads which result in aggressive driving.

In Shinar’s (1998) multi-factorial approach to aggressive driving, rarely would a

single factor in isolation directly cause the experience of frustration and expression of

road aggression (Shinar, 1998). A review of the literature on person-related and

situational factors indeed suggests that perhaps congestion and delays, as detailed in

Shinar’s model, only result in the expression of aggressive driving in the presence of

particular person-related factors, including the subjective evaluation of the situation. As

such, perhaps the situational factor, ‘congestion’ does not cause sufficient frustration in

itself, due to the fact that it may be anticipated, particularly at certain times of the day

e.g. rush-hour.


2.5 Person-Related Contributors to Aggressive Driving

2.5.1 Age, Gender and Aggressive Driving

Research suggests that an individual’s aggressiveness may be susceptible to

change over the course of their life, increasing age being associated with lower

aggression levels (Harris & Knight-Bohnhoff, 1996a). Within this study, men also

reported significantly higher levels of physical aggression than women as measured by

the Aggression Questionnaire (Buss & Perry, 1992). As such, the age and gender of an

offending driver may also influence the amount of anger experienced and the type of

aggressive behaviour displayed.

In a study of cognitive antecedents to aggressive road behaviour, Yagil (2001)

posited that negative attributions, or negative evaluations/thoughts affect aggressive

reactions to another driver’s provocative road behaviour. Yagil’s (2001) study of 150

males found that negative attributions applied to another driver are likely to increase the

amount of driving related frustration or anger with male ‘offending drivers’ attracting

more negative attributions and emotions than females. Further, such negative beliefs

and expectations about another driver are more likely to result in evaluations of their

behaviour as being inconsiderate and aggressive (Yagil, 2001). This finding is

consistent with the VCCAV (1999) study, which found that younger men (aged 18–24

years) were reported three times more frequently than females as the perpetrators of

‘road rage’ incidents. However, it should be pointed out that Yagil’s (2001) study

involved males, and not females. The inclusion of both sexes is a step which is

considered necessary in light of the study by Lajunen and Parker (2001) which proposed

separate models of driver aggression for males and females, based on findings which

clearly highlight differing beliefs about aggressive road behaviour and the frequency of

those aggressive behaviours between males and females (Rimmo & Aberg, 1999;

Lawton, Parker, Manstead, & Stradling, 1997; Reason, Manstead, Stradling, Parker, &

Baxter, 1991).

Male drivers in particular have been found to behave more aggressively on the

roads than females (Rimmo & Aberg, 1999). Lajunen and Parker (2001) found the

amount of anger experienced in traffic and the severity of an aggressive response

decreases with increasing age. Shinar (1998) found that as age increases, aggressive


driving behaviour seems to decrease. He also reported that aggressive driving was more

common among men than women, particularly the more severe expressions of

aggressive driving.

These results have also been supported by the Australian VCCAV survey (1999)

which looked at the phenomenon of ‘road rage’ from the dual perspective of the victim

and the perpetrator. This study found that people aged 18–34 years, particularly males,

were significantly more likely to participate in ‘mild’ cases of aggressive driving than

the population as a whole (VCCAV, 1999).

Young males were also found to be over-represented in a study of New South

Wales police records of reported aggressive driving incidents (Harding, Morgan,

Indermaur, Ferrante, & Blagg, 1998. In contrast, Gordhamer, Martinex, Petrilli, Lynch

& Deffenbacher (1996), conducted a study of the characteristics of high and low anger

drivers. No significant effect was found for gender on ‘anger experienced’ within the

high anger group consisting of 28 males and 27 females. However, males and females

differed significantly in the expression of their anger with females reporting more

constructive/adaptive and less hostile/aggressive behaviour than males (Gordhamer et

al., 1996).

Overall, the findings of this review suggest that not only does age and gender

appear to influence the behavioural response to an anger-provoking road situation, it

appears to influence the subjective experience of frustration and anger on the roads

(Gordhamer et al., 1996). Specifically, young males appear to be more likely to

perpetrate acts of hostility and aggression on the roads. Considering the possible

individual differences between driver age groups, some aggressive driving researchers have emphasised the individual or trait differences

that may increase or decrease the likelihood of aggression (Deffenbacher, Oetting, &

Lynch, 1994; Lajunen & Parker, 2001). These are reviewed in the following sections.

2.5.2 Personality and Psychopathology

A review of traffic literature indicates that several measures of a driver’s trait

predisposition for stress have been utilised (Gregory, 1996). The Eysenck Personality

Questionnaire Revised – Abbreviated (EPQR-A) (Francis, Brown, & Philipchalk, 1992;

Forest, Lewis, & Shevlin, 2000) has been used to assess personality traits and their


relationship with driver behaviour. The EPQR-A consists of measures of Extroversion,

Neuroticism, Psychoticism, and a Lie scale (Gregory, 1996). Scores high on the

Extroversion subscale suggest an individual is more easygoing and less likely to keep

their feelings under control than introverts (low scores) and therefore perhaps more

likely to behave spontaneously in a given situation (Renner & Anderle, 2000). The

Neuroticism subscale reflects emotionality that ranges from ‘nervous, maladjusted and

over emotional’ (high scores), to ‘stable and confident’ (low scores) (Gregory, 1996).

High scores on the Psychoticism subscale are believed to reflect antisocial tendencies,

with high scores reflecting low socialisation, a disregard for rules, insensitivity to the

feelings of others and a tendency to accept high risk (Gregory, 1996). In 1978, Eysenck

and colleagues designed an additional questionnaire measuring Impulsivity,

Venturesomeness and Empathy (IVE) to be used in conjunction with the EPQR-A

(Eysenck et al., 1995).

In a 1991 study, Matthews and colleagues (1998) utilised the EPQR-A to

examine the association between personality traits and general driver stress (measured

by the Driver Behaviour Inventory – DBI) and accident involvement (measured by the

Driver Behaviour Questionnaire – DBQ). They found that general personality traits,

particularly ‘neuroticism’ and to a lesser degree ‘psychoticism’, are positively related to

an individual’s susceptibility to driver stress and increased involvement in aberrant

driving behaviour (Matthews et al., 1991).

The EPQR-A and the IVE have also been used by traffic researchers to examine

the characteristics of aggressive drivers (Lajunen & Parker, 2001; Renner & Anderle,

2000). In a comparison of known traffic offenders (aged 18–30 years of age) with a

control group of general applicants for driving licences, administration of the full EPQ-R

and the IVE yielded two significant results (Renner & Anderle, 2000). The known male

offenders scored significantly higher scores on ‘extroversion’ than males in the control

group. Also, the offender group scored significantly higher on ‘venturesomeness’ than

the control group. However, Lajunen and colleague (2001) found no evidence of the

IVE subscales contributing significantly to the prediction of on-road aggression. In this

study participants were required to self-report their levels of trait driving anger and

general aggression levels. They were then exposed to several on-road, anger-provoking


scenarios and asked to indicate the amount of anger they would be likely to experience

and then their most likely behavioural response (Lajunen & Parker, 2001). This

apparent lack of a significant contribution by the IVE subscales in the prediction of

aggressive reactions is understandable, as one would anticipate that the incidence of high

levels of ‘impulsivity’ or ‘venturesomeness’ would be relatively low in the sample used

(Eysenck et al., 1995). Further, high impulsivity has long been associated with poor

appraisal/decision making and risk-taking behaviour (D’zurilla, Chang, & Sanna, 2003;

D’zurilla, Nezu, & Maydeu-Olivares, 2002).

Other traffic researchers have examined clinical differences between self-

referred and court-referred aggressive drivers in an attempt to profile aggressive drivers

and consider appropriate clinical interventions (Galovski & Blanchard, 2002a). In this

study, the researchers administered the Structured Clinical Interview for DSM-IV Axis I

and II disorders. Of the 30 participants, 80% were found to meet the criteria for at least

one Axis I disorder (33% meeting the criteria for Intermittent Explosive Disorder – IED)

and 57% met the criteria for at least one Axis II disorder. The court-referred aggressive

drivers had significantly more Axis I and II psychopathology when compared to a

control group. Aggressive drivers were more frequently diagnosed with IED, alcohol

abuse, substance abuse, antisocial personality disorder and borderline personality

disorder (Galovski & Blanchard, 2002a).

In a 2001 study examining the relationship between psychiatric morbidity and

‘road rage’, researchers recruited both perpetrators, victims, and those that had

experience as both

the perpetrator and the victim of ‘road rage’ (Fong, Frost, & Stanfeld, 2001). The 131

participants were clinically assessed using the Clinical Interview Schedule – Revised

(CIS-R) (Lewis, Pelosi, Araya, & Dunn, 1992) the AQ (Buss & Perry, 1992), AUDIT

(Saunders, Aasland, Babor, De La Fuente, & Grant, 1993), Life Event Scale (LES)

(Holmes & Rahe, 1967) and Screening Test for Co-morbid Personality Disorders

(Dowson, 1992). Perpetrators were found to be predominantly young and male with

significantly less driving experience than all other groups. They also scored

significantly higher than the other groups on the trait aggression (AQ) and overall scores

on the CIS-R, suggesting psychiatric co-morbidity. However, there were no significant


differences found between the groups on exposure to major life events (LES), social

class, levels of alcohol abuse or prevalence of personality disorders.

Another study compared the prevalence of psychiatric diagnoses between self-

reported high and low aggression drivers with a mean age of 19.1 years (Malta,

Blanchard, & Freidenberg, 2005). This study found that the high aggression drivers had

significantly greater prevalence of current and lifetime diagnoses of Oppositional

Defiance Disorder (ODD), an alcohol and/or substance abuse disorder and personality

disorders across the three clinical clusters (A, B & C). Cluster A personality disorders

refer to Paranoid, Schizoid and Schizotypal diagnoses. Cluster B disorders refer to

Antisocial, Borderline, Narcissistic and Histrionic personality diagnoses, whilst Cluster

C disorders refer to Avoidant, Dependent and Obsessive-compulsive diagnoses. These

drivers were also found to have significantly greater current and lifetime prevalence of

Conduct Disorder, Attention-Deficit/Hyperactivity Disorder (ADHD) and IED. In this

study, however, no significant differences were found between the two groups for

prevalence of mood or anxiety disorders (frequently associated with the neuroticism

scale of the EPQ-R).

In conclusion, the foregoing research provides evidence to suggest that the key

differences between aggressive drivers and non-aggressive road users occur at the

personality level. In particular, the evidence concerning the greater prevalence of

lifetime psychological disorders, such as Oppositional Defiance Disorder, Conduct

Disorder, ADHD, personality disorders and alcohol abuse disorders, suggests that

perhaps these individuals are not only predisposed to a greater likelihood for aggression

on-road, but ‘off-road’ as well.

2.5.3 Trait Aggression

As real-life instances of human aggression are difficult to record and to measure

as they occur (O’Connor, Archer, & Wu, 2001; VCCAV, 1999) aggression researchers

have explored indirect methods of measuring human aggression. These methods have

included the manipulation of anger-provoking scenarios that generate aggressive

responses and the use of measures of people’s trait propensity to act aggressively.

Various personality measures and subscales have been used to assess trait aggression.

At times, however, they tend to measure far more than the trait propensity to act


aggressively or fail to assess in sufficient depth the different components of aggression

(Buss & Perry, 1992; Deffenbacher, Oetting, Thwaites, Lynch, Baker, Stark, Thacker,

& Eiswerth Cox, 1996; Matthews, Dorn, & Glendon, 1991).

In the construction of the AQ, Buss and Perry (1992) emphasised the

importance of dividing aggression into sub traits or components. Their research

concluded that the personality trait of aggression consists of four sub-traits. The

physical and verbal aggression subscales represent the instrumental component of

aggression. Viewed as the ‘bridge’ between negative thoughts/evaluations and reactive

aggression, the ‘anger’ scale represents the emotional component of behaviour and

reflects a trait preparedness for aggression. The hostility scale represents the cognitive

component of trait aggression, measuring thoughts of suspicion, injustices and ill-will

toward others (Buss & Perry, 1992). The initial set of questions was administered to 612

male and 641 female university students, almost all of whom were aged 18 to 20 years.

These results revealed that young males reported slightly higher on ‘verbal aggression’,

‘hostility’ and considerably higher on ‘physical aggression’ than young females.

However, there was no reported difference in ‘anger’ for gender.

Research into self-reported aggressive responses to anger-provoking social

scenarios has also used the AQ as a measure of aggression (O’Connor, Archer, & Wu,

2001). In this social experiment, young men below 28 years of age that endorsed the use

of ‘physical aggression’ on the AQ, chose to express more overtly aggressive responses

than females. However, it should be noted that in another all female study (n = 106), a

measure of social desirability was found to have a moderate to strong relationship with

the AQ, suggesting that females (mean age 20.3 years) may not be self-reporting

aggression tendencies honestly (Harris, 1997).

In another study of aggressive drivers, Lajunen and Parker (2001) constructed

different path analyses for males and females relating to their experience of anger and

expression of aggression on the road. Interpreting scores obtained from three of the AQ

subscales (anger, physical aggression and verbal aggression) (Buss & Perry, 1992), both

men and women that reported having high general ‘anger’ and/or high levels of ‘verbal

aggression’ seemed to become more angry by the reckless driving of others. Further,

those that scored high on ‘verbal aggression’ were found to be more aggressive the


angrier they got. However, ‘verbal aggression’ was not significantly related to the level

of anger or aggression that results from having their progress merely impeded. The trait

tendency to resort to ‘physical aggression’ was found to directly increase the likelihood

of an aggressive behavioural response. Although this research did not elaborate on

specific differences between young and older drivers, the researchers did report that with

increasing age there appeared to be a decrease in the amount of anger experienced and

aggression adopted among males (Lajunen & Parker, 2001).

2.5.4 Driving Anger

In America, Deffenbacher, Oetting and Lynch (1994) devised a 33 item measure

of general ‘driving anger’, the Driving Anger Scale (DAS). Driving anger was

conceptualised as a personality trait related to trait anger, but specific to road situations

(Deffenbacher et al., 1994). The measure consists of a series of statements representing

road behaviours displayed by ‘others’, e.g. ‘someone is driving well above the speed

limit’ and specific driving related situations, e.g. ‘someone backs out in front of you

without looking’. The items formed six subscales, which were named hostile gestures,

illegal driving, slow driving, traffic obstructions, discourtesy, and police presence

(Deffenbacher et al., 1994).

In a study utilising the DAS, researchers have found young self-reported high-

anger drivers (median age 19 years) reported more anger whilst driving, more aggressive

behavioural responses on-road, greater aggression and risk-taking behaviour

(Deffenbacher, Filetti, Richards, Lynch, & Oetting, 2003). They were also found to

possess higher levels of trait impulsivity and aggression. Additionally, these drivers

reported less controlled forms of anger expression.

A recent study into the relationship between trait aggression, driver anger and

aggressive driving suggested that although the anger-provoking situations in the DAS

(UK) may evoke feelings of anger, they do not necessarily lead to the expression of

aggression (Lajunen & Parker, 2001). Further, acknowledging that the DAS only

measures anger experienced and not expressed, Lajunen and Parker (2001) asked

participants to report their most likely resultant behaviour from a list of seven

possibilities, ranging from ‘no reaction’ to ‘physical/verbal assault of person or

property’. The responses of the participants revealed that the level of anger experienced


is related to the severity of the expressed aggression, with the various on-road situations

outlined in the DAS (UK), affecting the amount of anger experienced.

In an earlier study by Lajunen and colleagues (1999) investigating the

dimensions of driving anger (using the DAS) as experienced by UK drivers, factor

analysis yielded a three factor measure of driving anger i.e. reckless driving, direct

hostility and impeded progress by others (Lajunen, Parker, & Stradling, 1999).

Furthermore, young drivers were more likely to express all three types of driving anger

than older drivers. Interestingly, no gender differences were found between males and

females and the types of driving anger expressed.

Building on the construct of ‘driving anger’ some researchers have attempted to

characterise the differences between high and low anger drivers (Deffenbacher, Huff,

Lynch, Oetting, & Salvatore, 2000; Deffenbacher, Deffenbacher, Lynch, & Richards,

2003). Whether a driver was considered high or low anger was determined by high or

low total scores on the DAS (Lynch et al., 1999). In one study comparing students

seeking help for problems with driving anger, and two groups of students either high or

low on trait anger, researchers found that on certain characteristics there was very little

difference between either of the high anger groups (Deffenbacher et al., 2003). Both

high-anger groups reported greater frequency of intense anger, more aggressive ways of

expressing driving anger (as measured by the Driving Anger Expression Inventory -

DAX) and more risk-taking behaviour.

In a closer examination of high-anger drivers, research has found that not only do

high-anger drivers self-report higher levels of intense anger and anxiety (Deffenbacher

et al., 2000), but they also report greater anger in frequently occurring on-road

situations. They also experience more frequent near misses and a greater number of

moving violations (Deffenbacher et al., 2003). Young high-anger drivers (median age

19 years) were also found to drive at higher speeds in low impedance simulations with

shorter stopping times/distances (Deffenbacher et al., 2003). Additionally, these

researchers observed that these drivers were also more generally angry individuals.

Collectively, the foregoing findings indicate that aspects of trait driving anger

appear to influence the likelihood of aggressive driving behaviour. Also, where the

research has examined a cross-section of high and low-anger drivers, the findings


suggest that the link between feelings of anger and the expression of aggression on the

road is quite complex.

2.5.5 Impulsivity

Impulsivity is a trait tendency to act spontaneously without considering all of the

relevant characteristics of a situation and the consequences of such behaviour (Lajunen

& Parker, 2001). Hence, high impulsivity is considered to have a strong association

with increased risk-taking behaviour, which is particularly prevalent among young males

(Deffenbacher, Filetti, Richards, Lynch, & Oetting, 2003; D’Zurilla, Nezu, & Maydeu-

Olivares, 2002).

As traffic conditions change rapidly and communication is constrained in the

road environment, perhaps impulsive responses are more likely in today’s environment.

Lajunen and Parker (2001) hypothesised that impulsivity would be related to a readiness

to act aggressively in a frustrating road situation. Despite this, they found that

impulsiveness was not predictive of driver aggression in a self-report study. However,

perhaps this finding was due to the wide age range of the participants in the study, as

‘impulsivity’ is generally quite evident in the behaviour of young males (Eysenck et al.,

1995; Deffenbacher, et al., 2003; Karli, 1991). Further, the arousal levels often

associated with spontaneous ‘impulsivity’ were not meaningfully elicited by the use of a

self-report measure. The relevance of impulsivity to human aggression will be discussed

in greater detail in Chapter Three.

2.5.6 Sensation-Seeking

Sensation seeking is a personality trait or disposition characterised by the desire

to partake in novel or unconventional experiences, which involve a willingness to take

physical and social risks (Zuckermann & Neeb, 1980). For instance, sensation-seekers

are more likely to be involved in high-risk activities such as bungy jumping or

parachuting. Further, it has been found that these individuals are less inhibited than

most, are easily bored and more likely to engage in risky driving practices (Zuckermann

& Neeb, 1980). Specific to driving behaviour, the sensation seeking trait has been

found to be related to aggressive driving, running red lights and speeding (Jonah, 1997).

In a 1997 meta-analysis, Jonah found that 36 of the 40 studies reviewed reported

a significant positive relationship between sensation seeking and risky driving. Jonah


(1997) also reported that all studies involving risky driving measures reported a

significant positive relationship with sensation seeking. High sensation seekers have

been found to be more likely to follow other vehicles at a closer distance, whilst also

being more likely to judge their driving behaviour as less risky than it probably is

(Rimmo & Aberg, 1998). Therefore, perhaps sensation seeking contributes to on-road

behaviours which are interpreted as aggressive by other road users.

2.5.7 Self-Esteem

It has been found that males tend to have higher levels of self-esteem than

females, although this difference appears to diminish across time (Baumeister, Smart, &

Boden, 1996). Those individuals with high self-esteem have been found to react poorly

to criticism in general and may respond irrationally by raising the levels of their own

future performance at tasks (Baumeister, Bushman, & Campbell, 2000; McFarlin &

Blascovich, 1981; Schlenker, Soraci, & McCarthy, 1976). Conversely, other research

de-emphasises the importance of self-esteem and highlights the larger, however, closely

associated psychological construct, i.e. ‘ego’ (Bushman & Baumeister, 1998). ‘Ego’

may be conceptualised as the core of an individual, comprising “the collected

psychological processes that are concerned with one’s ‘self’” (Reber & Reber, 2001, p.

195). Considered in unison, these constructs may contribute to a better understanding of

why young males, in particular, appear over-represented in aggressive driving research.

For example, the acquisition of a vehicle and the obtaining of a licence may add to a

young male driver’s perception of self-importance, increasing their self-esteem and

inflating the ‘ego’. As such, a perceived threat to that ‘ego’ or self-esteem may result in

aggressive driving behaviours aimed at restoring their self-esteem, ‘ego’ and sense of

‘superiority’.

In sum, the above findings may suggest that in response to the external challenge

to their self-esteem, some male drivers may respond irrationally by pushing their limits

or engaging in risk-taking road behaviour which they believe they) can manage

(McFarlin & Blascovich, 1981; Schlenker et al., 1976). Perhaps it should also be

considered that stepping into the vehicle may indeed enhance a young driver’s self-

esteem and subsequent perception of their own driving abilities. The subsequent


perception of on-road threat to their favourable self-appraisal may result in irrational or

‘impulsive’ responses aimed at restoring their positive self-impression.

2.5.8 Transfer of Stress to and from the On-Road Environment

The term ‘stress’ refers to any force that causes modification of a person’s

physiological or psychological ‘state’, and usually in a negative manner (Reber & Reber,

2001). Individuals may experience stress from physical, psychological, and social

pressures (collectively known as stressors) within their lives that may negatively impact

on their behavioural responses across a variety of situational settings (Carlson &

Perrewe, 1999; Vaughan & Hogg, 1995). A stressor does not need to be severe or have

a psychological or physiological impact on one’s lifestyle in order to induce stress and

alter one’s ‘state’ (Carlson & Buskist, 1997). Although stress is experienced internally

within oneself via physiological changes and psychological effects, the experience of

stress may be observed in subsequent behavioural responses that may appear to

differentiate from an individual’s ‘normal’ behaviour (Aseltine, Gore, & Gordon, 2000;

Westerman & Haigney, 2000).

Traffic research has highlighted the relevance of such state-related characteristics

and their influence on aberrant driving behaviours (Simon & Corbett, 1996). These

researchers have found that on and off-road generated stress is positively associated with

road traffic offending rates among both males and females (Simon & Corbett, 1996).

Therefore, further to the relative contribution of the on-road factors noted above, it is

necessary to elaborate on psychological constructs that a driver inherently brings to the

road environment. These psychological constructs, such as ‘mood’ and ‘life-stress’,

originate from within an individual and are considered relatively transient emotional

states. As such they are difficult to quantify, however, research has found evidence of

mood negatively effecting road user behaviours (Hartley & Hassani, 1994; Kolich &

Wong-Reiger, 1999; Matthews, Dorn, Hoyes, Davies, Glendon, & Taylor, 1998; Simon

& Corbett, 1996).

Given that road networks are becoming increasingly complex and congested,

traffic researchers have long been interested in the impact of state stress on-road user

behaviour. The following section explores some of the relevant on and off-road, person-


related stressors that may influence the likelihood of aggressive driving. However, it is

first necessary to briefly discuss the experience of stress and road user behaviour.

2.5.8.1 The Experience of Stress on the Road

Under conditions of stress drivers are more likely to exhibit mild forms of

aggression and a greater number of errors and violations on the road (Aseltine et al.,

2000; Deffenbacher et al., 2000; Gulian, Matthews, Glendon, Davies, & Debney, 1989;

Hartley & Hassani, 1994; Wiesenthal & Hennessy, 1999). The original source of such

stress is not confined to the on-road environment. As in other stress research, exposure

to considerable stress has been found to spill over into other life situations (Hennessy &

Wiesenthal, 1997). In traffic psychology, it has been suggested that this is primarily due

to findings that stress negatively impacts on a driver’s coping abilities within the

complexities of the driving environment (Westerman & Haigney, 2000; Novaco,

Stokols, & Milanesi, 1990). As a consequence, many drivers experience feelings of

frustration, irritation and even anger, which can further enhance the likelihood of their

engaging in erroneous or aggressive driving (Aseltine et al., 2000; Deffenbacher et al.,

2000; Westerman & Haigney, 2000).

In general, driver stress is believed to be an internal, individual experience

influenced by personality ‘traits’, that may also occur in combination with

environmental or life stressors (Hennessy & Wiesenthal, 1997; Arnett, Offer, & Fine,

1997). Environmental or life stressors, as ‘state’ stressors, affect an individual’s current

mood, whereas trait level stress is considered to be a relatively stable and enduring

individual predisposition to stress in general (Arnett et al., 1997). Therefore, not only do

drivers bring their enduring trait predisposition for stress to the road environment, they

also bring with them their current ‘mood state’. As stress levels are likely to build

across relatively short periods of time, it is possible that drivers may adopt risky driving

practices to release their stress or they may become angered more easily in response to

other driver behaviour increasing the likelihood of aggressive driving (Navaco et al.,

1990; Parkinson, 2001). For example, a road stressor such as congestion may add to

existing feelings of stress associated with work or home (Matthews, Dorn, & Glendon,

1991; Navaco et al., 1990). As such, some researchers believe that stress experienced on


the road may similarly transfer into the work or home environment (Navaco et al.,

1990).

2.5.8.2 Effect of Gender and Age on the Experience of Stress

As in other areas of traffic research, gender and age may influence the amount of

stress experienced on and off-road and the behaviour displayed. Research based on self-

report measures of general life stress and driving stress, found that stress both on and

off-road is positively correlated with traffic offending in both male and female drivers

(Simon & Corbett, 1996; Hartley & Hassani, 1994).

In a large UK study (Westerman & Haigney, 2000), researchers found that self-

report measures of trait driver stress levels (using the Driving Behaviour Inventory –

DBI) revealed no significant differences between the sexes. However, there was a

negative correlation with age. The researchers acknowledge that this finding may have

been potentially confounded by the reported driving experience of the participants

(Westerman & Haigney, 2000). Further, several studies indicate that older drivers tend

to report lower trait stress than younger drivers (Guilan, Matthews, Glendon, Davies, &

Debney, 1989; Matthews et al., 1991; Simon & Corbett, 1996). Although it was noted

by Simon and Corbett (1996) that generally female drivers offend less than males,

females experienced slightly more stress than males regardless of their level of

offending. However, as previously mentioned, male offenders scored significantly

higher on ‘extroversion’ (as measured by the EPQR-A) (Renner & Anderle, 2000) and

were more likely to behave spontaneously in a given situation than male non-offenders

(Renner & Anderle, 2000). Hence, these findings may suggest that young male drivers,

in particular, may be more prone to react overtly and impulsively when under stress on

the roads and therefore more highly reactive in their behavioural response.

2.5.8.3 Driver Trait Stress Measures

Traffic researchers have repeatedly reviewed the relationship between stress and

driving violations and/or errors. Many researchers have utilised the Driver Behaviour

Inventory-General (DBI) that was designed as a behavioural outcomes measure of a

driver’s trait susceptibility to driver stress (Glendon, Dorn, Matthews, Gulian, Davies, &

Debney, 1993). This questionnaire consists of 31 items that load onto five scales: driver

aggression; irritation when overtaken; driving alertness; dislike of driving; and


frustration in overtaking (Glendon et al., 1993). A high score on the DBI reflects high

stress levels whilst driving (Glendon et al., 1993). Quite often this measure has been

used in conjunction with the Driver Behaviour Questionnaire (DBQ) which gives a

measure of on-road behavioural outcomes that are classified as ‘lapses, errors and

violations’. Used in this way the DBQ has provided results that raise concerns about the

relationship between driver aggression and driver safety issues (Mizell, 1997).

Using the DBI, Hartley and Hassani (1994) reported that truck drivers with high

levels of traffic violations reported more general driving stress than low violation truck

drivers (Hartley & Hassani, 1994). Conversely, they reported that the reverse is true for

car drivers (Hartley & Hassani, 1994). In another study, with a sample of 2,806 United

Kingdom drivers, similar results were found: researchers reported that high levels of

driving stress were consistently found to be associated with increased self-reported

lapses, errors and violations on the roads. In particular, this study found a strong

positive correlation between the DBI ‘driving aggression/urgency’ factor and road

violations (Westerman & Haigney, 2000). The particular items that featured

predominantly in the ‘driving aggression’ measure highlighted the role of

interpersonal/social aggression tendencies (Westerman & Haigney, 2000).

However, other research provides a better explanation of stress and increased

involvement in road violations. Matthews and colleagues (1991) found high correlations

between high driver stress (measured by the DBI) and poorer self-rated ‘attention’ to the

road environment (Matthews, Dorn, & Glendon, 1991). Other traffic research using the

DBI clearly shows sex differences for the levels of driving stress experienced (Simon &

Corbett, 1996). Also, several studies based on use of the DBI indicate that older drivers

tend to report lower levels of driver stress than younger drivers (Guilan, Matthews,

Glendon, Davies, & Debney, 1990; Matthews et al., 1991; Simon & Corbett, 1996).

In a study conducted in the United States, researchers found that drivers who

perceived the driving environment as more stressful reported a greater likelihood of

behaving aggressively on the road (Hennessy & Wiesenthal, 2001). High stress drivers

were also found to report higher incidence of past road violence (Hennessy &

Wiesenthal, 2001).


Collectively, the above findings suggest that high levels of trait and state driver

stress do contribute to lapses in driver attention, increased driver errors, increased rates

of violation of road rules and aggressive driving behaviour. As such, the importance of

stress levels and its impact upon road user behaviour is highly relevant when considering

on-road aggression.

2.5.8.4 Individual Mood and Daily Hassles

The experience of DBI measured driver stress has also been found to correlate

with stressed mood states and crash involvement (Matthews et al., 1991). Comparing

participant scores on the DBI and the UWIST (University of Wales Institute of Science

and Technology) mood measure, researchers found evidence to suggest that the ‘dislike

of driving’ and ‘overtaking tension’ scales of the DBI, were strong predictors of a

driver’s state mood (Matthews et al., 1991). Specifically, high scores on these two

scales were associated with low levels of arousal, high tension and a less pleasant mood

state (Matthews et al., 1991). However, the relationship between ‘off-road’ daily life

stress and driver mood appears more complex.

In a more general approach to the effect of daily stress on mood, researchers

DeLongis and colleagues (1988) found a significant positive relationship between life’s

daily hassles and reported stress levels, however, the negative effect of such was short

lived, usually less than a day (DeLongis, Folkman, & Lazarus, 1988). Therefore, young

drivers in particular, in light of this critical developmental period in their lives, may

experience similar effects. Certainly this literature review suggests that younger drivers

are more susceptible to on and off-road stressful events and mood disturbances than

older drivers.

Road researchers have also found that higher levels of ‘perceived’ impedance

(stress) in the work or on-road environment, in the form of perceived delays due to work

or congestion when driving home, are associated with greater negative mood states on

arrival at home from one’s place of work (Navaco et al., 1990). Higher levels of general

life stress have also been found to negatively impact cognitive information processing

ability in the workplace, as measured by reaction times based on task difficulty and

driver performance (Kolich & Wong-Reiger, 1999; Matthews et al., 1998).


2.5.8.5 Life Event Stress

The Holmes and Rahe (1967) 43 item, Life Event Stress Questionnaire (LES) has

been used to assess the impact of major life stressors such as divorce, death of a family

member and changing jobs, on human performance (De Meuse, 1985). De Meuse

(1985) reported that younger individuals seemed to perceive such major life events as

having a greater negative impact on their lives than did middle-aged or older

participants. This finding was more recently supported by Simon and Corbett (1996).

Again, older drivers reported less general life stress than younger drivers, and in

particular, young male drivers had higher overall self-reported life stress scores (Simon

& Corbett, 1996). As previously stated, higher stress scores were related to higher levels

of traffic offending for both males and females (Simon & Corbett, 1996).

General aggression researchers have found evidence to suggest that higher levels

of anger and hostility in response to negative life events as a youth, play a causal role in

fostering more aggressive forms of delinquent behaviour in youth (Aseltine, Gore, &

Gordon, 2000). This delinquent behaviour may extend to road user behaviour. Even

early research speaks of the impact of life event stress on road user behaviour. In 1970,

McMurray found that drivers involved in fatal crashes are more likely to be undergoing

periods of personal stress and that these drivers are more likely to use a vehicle as an

outlet for their stress (McMurray, 1970).

Life-stressors appear to influence the perceived levels of stress generated by on-

road experiences and may influence the behavioural response of drivers. Notably, the

impact of life-stressors upon road user behaviour should not be diminished by the

possibility of a relatively small effect size when considering the multiplicity of factors

that affect the experience of on-road stress. The above findings suggest a very complex

relationship exists between life-event stressors and road user behaviour, however a link

has been established.

2.5.8.6 Work Stress

In 1981, a study assessed the cross-domain effects of work/home stress and

transportation stress (Stokols & Novaco, 1981). Job satisfaction levels were found to be

positively correlated with on-road stress levels during the commute home (Stokols &

Novaco, 1981). Conversely, efforts and ability to cope with the transport environment


have been found to affect levels of satisfaction across the work/home domains (Stokols

& Novaco, 1981).

As fleet safety research expands in an effort to reduce the massive costs

associated with higher levels of crash involvement (Downs, Keigan, Maycock, &

Grayson, 1999), research has begun to focus on the specific effect of stress levels on the

incidence of road crash involvement among company car drivers. Using motor vehicle

claims data sourced from within a large retail company, Cartwright and colleagues

(1996) found that occupational stress is playing a role in predicting crash rates

(Cartwright, Cooper, & Barron, 1996). In particular, those company drivers involved in

traffic accidents were found to have significantly lower levels of job satisfaction

associated with feelings of achievement or growth, the job itself, the organisational

structure and processes, and with their employment overall, than accident involved

drivers from another company (Cartwright et al., 1996). This evidence suggests that

more stressful work environments are likely to result in a higher incidence of accident

involvement. Moreover, the above findings suggest work stress is capable of inducing

stress, which in turn may influence the behaviour of all road users. Therefore, the

potential for work related stress to influence aggressive driving behaviour should be

investigated further.

2.5.8.7 Fatigue

In a small meta-analysis of fatigue studies, Milosevic (1997) found that the

experience of fatigue by bus and truck drivers negatively influences mood state,

specifically increasing irritability. Consistent with the above findings, this may suggest

that fatigued drivers would therefore experience an increased likelihood of stress and

subsequent ‘impatience’ associated with traffic delays or the behaviour of other road

users. Hence, fatigue appears to exacerbate certain trait and state person-related factors,

which influence the onset of driver stress. In turn, this stress may increase the likelihood

of aggressive driving behaviour.

2.6 Situational Contributors to Aggressive Driving

As previously stated, the large number of context specific situational

characteristics that may contribute to aggressive driving makes it difficult to examine

them all in a systematic way. Nonetheless, it is important to acknowledge the influence


that situational factors can have on aggressive driving. The situational factors that

influence aggressive driving appear to fall into two broad categories: the specific

behaviours of ‘other drivers’, and the situational factors of the immediate driving

environment.

The behaviour of ‘other drivers’ most often associated with aggressive driving

are listed below. However, it should be noted that it is more often combinations of these

behaviours that have been repeatedly cited as comprising or contributing to aggressive

driving behaviour (AAMI, 2001, 2003; NHTSA, 2002; Mizell, 1997):

• Speeding • Cutting-off

• Lack of indicating • Failing to allow merging

• Sudden lane changes • Gesticulating at other road users

• Sudden braking • Verbal abuse

• Horn-honking • Physical abuse.

Considered individually some of these behaviours may be indicative of poor

judgement or driving errors. However, when these behaviours are coupled with a degree

of ‘intentionality’ they may be considered aggressive driving, as proposed in the

‘provisional’ definition (Section 2.2.5.3).

2.6.1 On-Road Situational Factors

Other situational factors associated with aggressive driving concern the

characteristics of the on-road environment in which it is more likely to occur. The

following sections provide a brief overview of the findings concerning the most likely

conditions under which aggressive driving behaviour appears to take place.

2.6.1.1 Type of Road

Aggressive driving occurs on most types of roads. Despite this, a greater number

of incidents appear to be reported on freeways or major roads (VCCAV, 1999). It

should be noted however, that most of the research into aggressive driving behaviour has

focussed on built-up areas that naturally experience higher levels of traffic density i.e.


congestion (Elliott, 1999; RACWA, 1997; VCCAV, 1999), potentially increasing the

possibility of aggressive driving behaviour via an exposure effect. ‘Congestion’ and its

effect on driving behaviour is reviewed below as an example of how situational factors

may influence aggressive driving.

2.6.1.2 Congestion

Congestion is often used in road research to operationalise the fast-paced,

stressful environment of today’s road systems (Shinar, 1997; Lajunen, Parker, &

Summala, 1999). In a study of causal factors associated with anger while driving,

drivers were asked to keep a diary of ‘near accidents’ whilst driving over a period of two

weeks (Underwood et al., 1999). Drivers were required to record any feelings of anger

they experienced during this period. Although this study revealed a strong positive

relationship between the number of near accidents and the number of occasions anger

was experienced (particularly when a driver felt they were not at fault), and drivers were

more likely to report anger where frustration was present, there was no evidence to

suggest that drivers who experience higher levels of congestion experience more anger

(Underwood et al., 1999). In another self-report study of driver-behaviour across three

countries, Great Britain, Finland and the Netherlands, it was found that there was little

evidence of a relationship between driver exposure to varying levels of congestion and

aggressive driving (Lajunen et al., 1999). Lajunen and colleagues (1999) had

hypothesised that ‘frequent exposure’ to traffic congestion (a source of frustration)

should lead to increased aggression on the roads. The results of their study showed that

the relationship between frequency of exposure and aggressive driving was, in fact,

weak. However, they acknowledge periods of increased congestion may often be

associated with peak-hour traffic, due to travel to and from work. As such, perhaps

drivers consciously anticipate delays associated with congestion, therefore, perhaps they

experience lower levels of frustration and anger.

Consistent with these findings, Gordhamer and colleagues (1996) found that high

anger drivers [those scoring > 53 on the trait Driving Anger Scale (DAS)] not only

reported greater levels of anger in rush hour traffic, but also reported significantly more

anger than low anger drivers [those scoring <42 on the trait Driving Anger Scale (DAS)]

under normal traffic conditions. Further, the analysis of expressed ‘driving anger’


revealed high anger drivers participated in more hostile aggression than constructive

instrumental behaviours in either traffic conditions (Gordhamer et al., 1996). Both of

these studies suggest there is a more complex relationship between feelings of

frustration, congestion levels and the expression of aggression on the road.

A series of studies conducted by Hennessy and Wiesenthal (1997, 1999)

reviewed driver trait dispositions for stress and their self-reported stress levels during

periods of high and low congestion on the roads. Regardless of an individual’s trait

disposition for stress, all drivers reported higher stress in the high congestion condition

(Hennessy & Wiesenthal, 1997). The highest stress levels were reported by individuals

‘high’ in trait disposition for stress (Hennessy & Wiesenthal, 1997, 1999). Additionally,

aggressive driving behaviour increased from the low to high congestion, especially for

those measuring high in trait stress (Hennessy & Wiesenthal, 1997). This study also

found that ‘time pressure’ predicted state driver stress in low road congestion, whereas

‘driver aggression’ (as measured by the Driving Behaviour Inventory [DBI]) best

predicted driver stress in heavy congestion (Hennessy & Wiesenthal, 1999).

These findings suggest that congestion has the potential to influence aggressive

driving outcomes, primarily when mediated by person-related factors such as state stress

levels or trait driving anger. In keeping with the review at Sections 2.3.8 and 2.3.9, a

driver’s state driver stress levels are mediated by a driver’s trait disposition for stress in

general. The reported levels of state stress in congestion also appear to influence the

adoption of on-road behaviours. In high congestion conditions a wider range of

behaviours appear to be adopted by drivers, which include speeding and aggressive

driving (Hennessy & Wiesenthal, 1999).

2.6.1.3 Interim Summary

It is not possible to review all of the situational factors that have reportedly

influenced aggressive driving outcomes. However, thus far, the review indicates that a

wide range of situational factors influence the likelihood of aberrant driving behaviour

and more specifically aggressive driving. It also appears that such behaviours may

result via two possible emotional states; either frustration induced anger or excitement.

The altered emotional state may have the potential to alter physiological arousal levels

resulting in ‘stress’. Resultant on-road behaviours, such as speeding, cutting-off,


tailgating or ‘hooning’ with peers may be observed by ‘other drivers’ and law

enforcement officials as ‘aggressive’ in nature. Further, for some drivers, off-road

factors may at times generate feelings of on-road stress e.g. running late for a meeting.

Therefore, the relative contribution of preceding off-road stressors and their potential

transfer to the on-road environment should also be considered in aggressive driving

research. The foregoing review has confirmed the importance of person-related factors

in aggressive driving research. It appears they mediate the impact of situational

characteristics upon arousal levels and subsequent driving behaviours. Consequently,

the following section will review issues relevant to risk-taking and aggressive driving

which appear specific to at-risk drivers.

2.7 Issues Specific to At-Risk Drivers

2.7.1 Lifestyle

Today, there is greater understanding of the developmental difficulties that face

young people (17–24 years). Not only do many young people at the lower end of this

age range continue to experience physiological changes (Berk, 1997), many experience

difficulty adjusting to changing psychosocial demands as they leave school, gain

employment and possibly leave home, for the first time (Mortimer & Shanahan, 1994).

For young drivers, driving is far more than a means of transport, for many it is

considered symbolic of status, a means for exerting a sense of independence and making

a statement of ‘masculinity’ for males, all of which may contribute to ego (Zimbardo,

Keough, & Boyd, 1997). High-risk driving behaviour by young drivers has also been

found to be associated with self-reported experimentation with drugs and alcohol,

delinquent behaviours and risky sex practices (Jessor, 1987).

In a longitudinal study into the lifestyle of young drivers that participate in high-

risk driving behaviours, it has been found that high-risk adolescents tend to originate

from backgrounds that offer multiple negative influences: low familial nurturance and

connectedness, low monitoring of adolescent activities, and permissive attitudes to

drinking (Shope, Waller, Raghunathan, & Patil, 2001). Further, Shope and colleagues

(2001) found that illegal substance use at 15 years of age is an important predictor of

serious on-road offences or crashes for both males and females.


At this point, it should be noted that it is not only 17–24 year olds who engage in

risk-taking behaviours. Older individuals are also known to participate in such

behaviours. Therefore, it would be fair to suggest that a number of young individuals

continue to participate in risk-taking behaviour across the course of their lives. This will

be discussed in greater detail in Chapter Three (Section 3.5).

2.7.2 Education Attained

In a study of 18–64 year olds (n = 194), education level attained has been found

to have a negative relationship with individual tolerance for aggression (Harris &

Knight-Bohnhoff, 1996). In another large study of recorded crashes spanning 1988–

1994, young drivers (16–22 years) with minimal formal and/or a vocational education

were found to be over-represented in traffic accidents (Murray, 1998). Young males

involved in injurious traffic accidents were found to have a lower level of education than

females within the sample (Murray, 1998).

Specific to unsafe driving practices, education has been found to have a negative

relationship with such behaviours as speeding and drink driving, irrespective of age

(Shinar, Schechtman, & Compton, 2001). Harris and colleague (1996a) would suggest

that this may be due to higher levels of education teaching individuals to think laterally

when problem solving. Further, they suggest it may teach people to balk at ‘impulsive’

emotional responses and resort to more thoughtful, deliberate responses. Although these

findings do not suggest a distinct relationship between lower education levels and

aggressive driving behaviour, the trends identified by the foregoing research would

suggest that a relationship between education levels and aggressive on-road behaviours

may exist for at-risk driver groups.

2.7.3 Driving Experience

The distance a driver travels in a year is often used in traffic research as a

measure of driving experience and possible exposure to a wider variety of road

incidents. In America, annual mileage has been found to correlate positively with the

number of accidents a driver is involved in within the previous three-year period (West,

Elander & French, 1993). Conversely, inexperience has also been found to contribute to

a significant proportion of crashes on Queensland roads (Queensland Transport, 2003).

Focusing on the 17–24 year old age group, road crash involvement by young drivers has


been found to decline incrementally with each passing year that a licence is held (Elliott,

Waller, Raghunathan, Shope, & Little, 2000). In a self-report study of driving ability, it

has been found that driving experience, as measured by ‘number of years licensed’, is a

significant predictor of the effective use of safety behaviours on the road (Shinar et al.,

2001).

Specific to aggressive driving research, as annual mileage increases, anger

experienced and aggression decreases, especially among women (Underwood et al.,

1999). Also, older, higher mileage drivers report less irritability in response to other

driver behaviour whilst younger, low mileage drivers seem to be more easily irritated by

the road behaviour of others (Lajunen et al., 1998). As such, it appears that through

increased road exposure, the majority of the driving population become more tolerant of

the aberrant driving behaviour of others and may become less likely to feel as angry or

to have an aggressive response. However, a study comparing drivers identified as ‘high’

and ‘low-anger’ drivers revealed no difference in driving frequency or distance travelled

(Deffenbacher et al., 2000, indicating that regardless of driving experience a number of

drivers remain relatively more easily irritated or angered by the on-road behaviour of

others. Hence, there is a need to examine the characteristics of these drivers and how

they differ from other drivers.

2.7.4 Passenger Effect

Driving with passengers is not unique to the young driver population. However,

the probability of crash involvement for young drivers doubles when there are two or

more peers onboard, possibly due to distraction and increased risk-taking factors

(Doherty, Andrey, & MacGregor, 1998; Williams, 2003). In an earlier study, young

males reported the greatest detrimental effect on driving behaviour when passengers

were from their peer group (Rolls, Hall, Ingham, & McDonald, 1991). Conversely, they

also reported the greatest positive effect on driving behaviour when the passenger was a

parent or elderly person (Rolls et al., 1991). Females reported an adverse effect on

driving behaviour in the presence of a male (Rolls et al., 1991).

In a more recent study of ‘passenger effect’, 429 participants aged approximately

17–25 years were randomly targeted by a handheld radar when obviously unimpeded by

any other traffic (Waylen & McKenna, 2001). Careful observation was required to


determine the number of passengers present and an estimation of age was made (Waylen

& McKenna, 2001). This study revealed that young drivers aged 17–25 years,

regardless of gender, travelled faster when a male passenger was present than those

travelling without a passenger (Waylen & McKenna, 2001). The findings also suggest

an increased use of speed in the presence of passengers that may compound the possible

consequences of their on-road behaviour.

Of the several psychological constructs that have been used to explain this

phenomenon, one seems intuitively applicable to young male drivers, i.e.

‘competitiveness’ (Waylen & McKenna, 2001). Young males are believed to be more

competitive than females (Houston, Farese, & La Du, 1992). In this regard, speeding

may be considered a way of demonstrating perceived skill and superiority by young

male drivers. Consequently, it may be that the presence of a male passenger brings out

this competitive aspect in drivers. Alternatively, it may be that the presence of

passengers decreases the monitoring of travelling speed.

Although ‘competitiveness’ has more positive connotations than ‘aggression’,

‘competitiveness’ may result in instrumental, assertive behaviours that may easily be

viewed as ‘aggressiveness’ by others. Generally, one would anticipate a negative effect

in the form of aberrant driving behaviour, such as speeding, in keeping with the findings

about passenger effect. Additionally, another possible influence of the ‘passenger

effect’ may be in the young driver’s ability to accurately appraise the behaviour of ‘other

drivers’. Perhaps in an aroused state, they would be more likely to interpret ‘other

driver’ behaviours as discourteous, aggressive, or as impeding their progress. As a

consequence, the resultant on-road behaviours arising from this elevated state may be

more ‘impulsive’ and reactive than deliberate and thoughtful, due to the possible

demands of peer passengers.

2.7.5 Motivation

Much of existing aggressive driving research has focused upon the emotional

antecedents to the expression of aggression on the road such as frustration and anger.

However, more recent research has suggested that increasing attention should be paid to

driver attitudes and motivations associated with aggressive driving behaviour. For

instance, drivers motivated by ‘vengeance’ are more likely to perceive on-road errors or


violations as intentional and purposeful (Hennessy & Wiesenthal, 2001) which increases

the likelihood of more extreme levels of aggression. In a study of 192 drivers (M age

26.22 years, SD 10.39), males reported higher levels of vengeful driving attitude

(measured by the Driver Vengeance Questionnaire) as well as higher levels of driver

violence (Hennessy & Wiesenthal, 2002). Therefore, perhaps the attitudes and

motivations preceding on-road behavioural responses, mediate the likelihood of

aggressive driving outcomes, possibly via more negative attributions and aggressive

thoughts being associated with more aggressive outcomes (Yagil, 2001).

The foregoing research highlights the role of ‘vengeance’ in aggressive driving.

Not only does this research refer to the young driver group, frequently cited in traffic

research, it also associates older male drivers aged 26 to 36 with on-road aggression

(Hennessy & Wiesenthal, 2001).

2.7.6 Drugs and Alcohol

The relationship between alcohol/drug abuse and aggressive behaviour is not

easily definable due to the relevance of multiple other factors such as social situation,

intake levels and prior social learning (Taylor & Hulsizer, 1998). However, general

human aggression research indicates that alcohol impairs social judgement by reducing

inhibitions or internal control processes (Volavka & Citrome, 1998), thereby increasing

the likelihood of aggressive behaviour. Furthermore, alcohol intoxication has been

associated with violent crime (Taylor & Hulsizer, 1998). Extensive research has also

been conducted on the effect of drugs on aggressive behaviour (Taylor & Hulsizer,

1998). To date, the most conclusive results have demonstrated a link between

psychostimulants such as cocaine and amphetamines and aggressive behaviour (Volavka

& Citrome, 1998). However, these results are also subject to consideration of other

factors such as dosage rates (higher dosage rates being associated with aggression),

method of intake, predisposition to aggressive tendencies and situational context

(Volavka & Citrome, 1998).

With higher levels of risk-taking behaviour prevalent in drivers aged 17–25

years, there may be an increased preparedness to partake in intoxicating amounts of

drugs and/or alcohol before driving (AAMI, 2001; Jonah, 1977). The AAMI research

found that 18% of young drivers aged below 25 years of age, believed it was safer to


drive after taking recreational drugs (marijuana and cocaine) than it was to drink drive.

In addition, 17% of young drivers surveyed believe that recreational drug use does not

make a driver behave aggressively (AAMI, 2001). A further 15% of young drivers

believed it was acceptable to drive after a few drinks as long as you feel ‘capable’

(AAMI, 2001).

A recent study into alcohol consumption and ‘road rage’ involved the telephone

survey of 2,610 participants aged 18 years and over. Of the sample, 32% admitted

shouting and gesticulating at another driver, 1.7% threatened another driver, and 1%

attempted or perpetrated physical damage to the other driver or their vehicle.

Problematic levels of alcohol consumption were found to have a significant relationship

with attempting or actually harming the other driver or their vehicle (Mann, Smart,

Stoduto, Adlaf, & Ialomiteanu, 2004).

These findings suggest that a proportion of drivers, particularly the young,

experiment with drugs and alcohol, and may underestimate the effects of these on

driving ability and subsequent decision-making processes. It is also clear that alcohol

consumption influences aggressive driving behaviour. However, it should be

acknowledged that problematic levels of drinking or drug-taking are not exclusive to the

young. This will be covered in more detail in Chapter Three (Section 3.2.2.1).

2.8 Focus of Emerging Interventions

Intervention programs for high-anger drivers or aggressive drivers in general

have only recently begun to emerge (Deffenbacher et al., 2000; Galovski & Blanchard,

2004; Larson, 1996). In the main, these programs are adopting a combination of

psychosocial, cognitive behaviour therapy techniques and are reporting some success.

However, this literature review would suggest that the phenomenon of aggressive

driving has yet to be understood sufficiently to facilitate the design of effective

programs. However, when considering aggressive driving perpetrators that have come

to the attention of the law, it should be considered that broad-based education relating to

the phenomenon of aggressive driving may better serve the community by reducing the

number of drivers that are prepared to initially engage in such behaviours.

A longitudinal study across the ages of 11 to 17 years concerning adolescent

predisposition to engage in risky or problem behaviours, has revealed that ‘impulsivity’


and an avoidant coping style are risk factors for participation in a variety of problem

behaviours, such as underachievement at school, substance use, delinquent behaviour

and sexual behaviour (Cooper, Wood, Albino, & Orcutt, 2003). The findings of this

study also suggested that emotionally driven behaviours and dysfunctional styles of

regulating emotions are core features associated with adolescent problem behaviours and

risk taking (Cooper et al., 2003).

Specific to aggressive driving behaviour, researchers have found evidence of a

relationship between the personality trait of ‘neuroticism’ and ineffectual coping

strategies (Dorn & Matthews, 1992). It has also been suggested that these ineffective

coping strategies mediate a driver’s ability to cope with driving related stress (Galovski

& Blanchard, 2002a).

With the emergence of interventions for aggressive drivers, some researchers

have focused upon reducing hostile, aggressive forms of anger expression on the road,

whilst increasing adaptive, constructive ways of expressing anger (Deffenbacher, Filetti,

Lynch, Dahlen, & Oetting, 2002). This was achieved by training participants in

relaxation and cognitive coping skills, resulting in reductions in the self-reported driving

anger, on-road aggression and frequency of risky behaviour.

Indeed, aggressive driving should be considered an emotion-based phenomenon.

Therefore, close examination of coping styles and strategies adopted by at-risk drivers,

in particular, is warranted. Clearer understanding of the coping styles and strategies

adopted by different drivers may inform the development of psycho-educational

packages aimed at reducing the probability of aggressive driving as well as enhance

interventions based on individual therapy for high-anger drivers.

2.8.1 Coping Styles in General

As aggressive driving research moves into the development of interventions,

researchers are looking more closely at internalised measures of coping (Deffenbacher,

Lynch, Oetting, & Swaim, 2002; Guilian, Matthews, Glendon, Davies, & Debney,

1989). Coping with stress, in general, may be conceptualised and measured in two

ways: in a more general approach, by the assessment of the internalised thoughts and

attitudes associated with stressful events; or in terms of the specific behaviours adopted

when placed under stress. The former approach is based on the assumption that an


individual’s predominant coping style may generalise to a wide range of adversely

stressful situations, including driving. The latter has been measured in terms of the

adoption of direct or indirect coping strategies (Folkman & Lazarus, 1980).

Direct coping is characterised by remaining problem focused and making

attempts to remove or avoid the source of stress. For example, direct coping strategies

would include information seeking, planning, taking precautions or altering a course of

action as outlined in the above research concerning coping strategies adopted by drivers

(Hennessy & Wiesenthal, 2001). Indirect coping is often referred to as ‘emotion

focused’ by nature (Folkman & Lazarus, 1980). Such coping strategies are characterised

by dealing with the experience of the problem. These strategies are characterised by an

inability to regulate one’s emotions, sometimes resulting in the expression of emotions

such as anger and at times resulting in more passive, avoidant type behaviours (Carver,

Sheier, & Weintraub, 1989). One psychological measure of coping that has emerged

from these concepts is the Social Problem Solving Inventory – Revised (SPSI-R).

The SPSI-R is designed to measure an individual’s ability to solve everyday

problems, not situation-specific problems. Specifically, the measure assesses two

constructive/adaptive dimensions and three dysfunctional dimensions of problem

solving. Five subscales are used to measure these dimensions: positive problem

orientation (PPO) and rational problem solving (RPS) versus negative problem

orientation (NPO), impulsivity/carelessness (ICS) and avoidance style (ACS). As can be

seen, these measures focus on two primary distinctions made in problem-solving

research: either positive or negative problem orientation. Problem orientation

encompasses the ways in which problems and events are perceived and interpreted by an

individual. The measure also explores problem-solving styles – avoidance, rational

problem solving and impulsive/careless (D’Zurilla, Nezu, & Maydeu-Olivares, 2002).

Effective problem solving has been found to be a significant mediator or moderator of

the negative effects of stressful events, with effective problem solvers reporting

significantly less stress (D’Zurilla & Nezu, 1999). Hence, this measure may serve to

illustrate the relationship between individual coping and the transfer of stress to and

from the road.


The SPSI-R has also been found significantly related to the Aggression

Questionnaire (AQ) (Buss & Perry, 1992) (D’Zurilla et al., 2003). Specifically, the

three dysfunctional measures on the SPSI-R (NPO, ICS and ACS) were found to be

positively related to ‘physical aggression’. In particular, the ICS was reported as a

unique predictor of physical aggression, the NPO subscale was found to be a strong

predictor of anger and hostility, and the RPS was found to be a predictor of hostility.

Research has also shown that deficits in positive problem solving increase the likelihood

of youth delinquent behaviour and violence (Dahlberg, 1998). Therefore, considering

the findings of the foregoing research perhaps this measure may elaborate upon driver

individual coping styles in stressful road situations and the increased probability of their

involvement in aggressive driving outcomes.

Using the SPSI-R (n = 904) research indicates that young adults (ages 17–20) are

lower on positive problem solving, rational problem solving than middle aged

participants aged 40–55 years. Additionally, they scored significantly higher on

negative problem solving, ICS and avoidance style. Young men also scored higher than

young women on ICS. Middle aged males scored higher than elderly participants (aged

60–80 years) on rational problem solving and positive problem orientation. Overall,

men scored higher on positive problem solving and lower on negative problem

orientation than did women (D’Zurilla, Maydeau-Olivares, & Kant, 1998). Within

middle aged participants, women were found to be higher on positive problem-solving

orientation and lower on ACS than men.

Problem orientation, negative or positive, is often uniquely predictive of negative

affect under general and stressful conditions (Elliott, Herrick, MacNair, & Harkins,

1994). Further, it has been suggested that the problem orientation has mood regulating

properties (Elliott, Shewchuk, Richisson, Pickelman, & Franklin, 1996). However, in

another study positive and negative affect were measured along with measures of the

SPSI-R (Shewchuk, Johnson, & Elliott, 2000). The results indicated that negative

problem solving was predictive of problem-solving performance, although this was not

mediated by negative affect.

Consideration of the literature review so far would suggest that aggressive

drivers may be predisposed to poor problem-solving ability. For example, in response to


an ambiguous on-road incident, aggressive, at-risk drivers may be more likely to adopt

less rational and more negative or impulsive/careless problem-solving strategies. As a

consequence, their behavioural responses to such an event may be perceived as more

highly reactive and aggressive.

2.8.2 Driver Coping Strategies

Within the confines of a vehicle, there are fewer constructive behavioural coping

alternatives available to drivers than would be available in other life situations. For

instance, it is not always possible to remove oneself from the source of on-road

frustration. Research into coping strategies adopted whilst driving have tended to use

measures such as the DBI (Glendon et al., 1993) and more recently the Driving Anger

Expression Inventory (DAX) (Deffenbacher, Lynch, Oetting, & Swaim, 2002). In such

research these measures have been utilised to focus upon the behavioural outcomes of

aggressive driving as measures of coping.

More specific information was obtained in a recent study of coping strategies

adopted whilst driving conducted by Hennessy and his colleague (Hennessy &

Wiesenthal, 2001). Using the DBI, these researchers found that most drivers preferred

direct coping measures such as ‘sticking to prearranged plans’, ‘listening to the radio’, or

‘watching for traffic changes’ especially, in high congestion conditions. However, it

was also noted that few drivers actually engaged in active preplanning. This study also

found that in high congestion conditions (considered a potentially stressful on-road

situation), aggressive driving behaviours such as deliberate tailgating and swearing or

yelling at other drivers increases. Another study found that listening to self-selected

music, serves to reduce self-reported stress levels particularly in high traffic congestion

(Wiesenthal, Hennessy, & Totten, 2000) which could be classed as a ‘direct coping’

strategy.

In the 2003 study conducted by Deffenbacher and colleagues of high-anger

drivers (median age 19 years) it was found that young male drivers reported more verbal

and physical aggression than did females in the same group. However, male and female

high-anger drivers reported less adaptive/constructive coping than low-anger drivers

(Deffenbacher et al., 2003a).


Recent research has developed the DAX (Deffenbacher et al., 2002b). The DAX

is a measure of how drivers express ‘anger’ on the road that consists of five subscales:

verbal aggressive expression, personal/physical aggressive expression, use of vehicle to

express anger, verbal aggressive expression and adaptive/constructive expression. Using

the DAX on a sample of 290 participants (median age 19 years), males and females were

found to participate in similar levels of ‘verbal aggression’, ‘use of their vehicles to

express anger’ and ‘adaptive/constructive’ expression of anger, i.e. ways in which a

person copes positively with anger by relaxing or focusing on driving (Deffenbacher et

al., 2002b). However, males were more likely to express their anger towards other road

users rather than the offending driver, and also to express their anger through physical

aggression (Deffenbacher et al., 2002b). Males also scored significantly higher than

females on the overall ‘total aggressive expression’ score provided by the DAX.

2.9 Research Questions

The foregoing review of the literature indicates some important questions

relating to the scope and nature of aggressive driving which remain unanswered or

require further investigation. The following research questions (RQs) requiring further

examination are proposed to guide this program of research:

RQ1 What are the person-related and situational factors contributing to aggressive

driving?

The foregoing evidence highlighted a number of person-related and some of the

situational factors believed to contribute to aggressive driving. However, this review is

in no way exhaustive. Additionally, the review highlighted some potential differences

between drivers at-risk of aggressive driving and general road users in the way different

factors influence the likelihood of aggressive driving. Other than a recent international

review conducted by the Victorian Parliament (DCPC, 2005), little known research has

been conducted into the person-related and situational characteristics that have the

potential to influence aggressive driving behaviour in Australian. Therefore, there is a

need to explore the range of contributing factors specific to Australian drivers.


RQ2 Are some drivers more likely to engage in aggressive driving and, if so, what are

their psychosocial characteristics?

The literature review suggests that young male drivers are a high-risk group for

aggressive driving behaviour (Harding et al., 1998; Lawton, et al., 1997; Reason,

Manstead, Stradling, Parker, & Baxter 1991; VCCAV, 1999; Yagil, 2001). However,

older drivers have also been cited in media reports of extreme on-road aggression within

Australia (DCPC, 2005). Therefore, more research is required in order to identify other

at-risk groups and personalities. Particular attention needs to be given to whether the

‘aggressive driver’ has certain person-related characteristics that increase the likelihood

of aggressive behaviours on the road.

RQ3 Is it appropriate to conceptualise aggressive driving as a continuum of related

behaviours?

A question also remains as to whether aggressive driving behaviours should be

conceptualised as a continuum of behaviours (Lajunen & Parker, 2001). The

instrumental/hostile distinction made in Shinar’s (1997) aggressive driving research

would suggest that these behaviours, though related, serve different functions. The

evidence would also suggest that the likelihood of adopting either instrumental or hostile

behaviours is influenced by a considerable number of other factors.

RQ4 What function does aggressive driving perform for drivers?

The distinction between the behaviours that constitute aggressive driving as either

instrumental or hostile as proposed by Shinar (1998) implies that on-road aggression

may be adopted in order to serve some functional purpose e.g. arriving at one’s

destination on time. However, for those drivers that are more likely to participate in

highly aggressive or hostile on-road behaviour, perhaps aggressive driving serves other

functions. Exploration of this issue warrants more attention in order to enhance

understanding of the nature and causes of aggressive driving, particularly among at-risk

drivers. In turn, such information may contribute to the growing knowledge base of

aggressive driving and eventually aid the design of effective driver education programs

and rehabilitation initiatives.


2.10 Chapter Summary

This chapter has provided a brief overview of aggressive driving literature,

highlighting specific issues associated with at-risk groups. As all drivers are arguably

exposed to similar situational factors, greater attention was paid to the person-related

factors that may enhance understanding of why some drivers are over-represented in

aggressive driving incidents. The review indicated that some groups of drivers

experience greater negative emotion and higher levels of impulsivity as a result of on-

road provocation and are more likely to engage in moderate to severe aggressive

behavioural responses.

Exploring the transfer of aggression to and from the on-road environment,

person-related and specific at-risk driver characteristics were extensively explored. On

several of the person-related factors explored, such as trait aggression in general, driving

anger, and factors such as motivations, self-esteem and competitiveness, findings

suggest young drivers may have a greater trait predisposition for aggression. The review

of person-related factors also suggested enhanced vulnerability and preparedness for

aggressive behaviours in the young driver group. However, other research suggests that

particular older drivers are also at-risk of engaging in higher levels of aggressive driving

on the road. In summary, these findings supported the concept of psychosocial

differences contributing to driver aggression, which require further examination. The

review then focused on coping styles and strategies in order to assess potential

differences between young and older drivers.

In order to examine the research questions outlined above, it is first necessary to

adopt a theoretical framework for the research. Therefore, the following chapter reviews

human aggression theory that may have the potential to enhance our understanding of

the psychology of aggressive driving.



Chapter Three: Aggression Literature Review

3.1 Introduction............................................................................................................. 69 3.1.1 Types of Human Aggression .................................................................... 69 3.2 Developmental Risk Factors for Aggression .......................................................... 71 3.2.1 Historical Factors...................................................................................... 73 3.2.1.1 Personal History of Violence and Delinquency ......................... 73 3.2.1.2 Family of Origin ......................................................................... 73 3.2.1.3 Victims of Abuse ........................................................................ 74 3.2.1.4 Negative Peer Relations ............................................................. 75 3.2.1.5 Schooling Problems .................................................................... 75 3.2.2 Clinical Factors ......................................................................................... 76 3.2.2.1 Substance Abuse ........................................................................ 76 3.2.2.2 Attitudes ..................................................................................... 77 3.2.2.3 Emotional Regulation Difficulties.............................................. 78 3.2.2.4 High Impulsivity ........................................................................ 80 3.2.2.5 General Life Stressors ................................................................ 82 3.2.3 Psychological Impact of Risk Factors ...................................................... 83 3.3 Psychological Theories Relevant to Aggressive Driving ....................................... 84 3.3.1 Frustration-Aggression Theory ................................................................ 84 3.3.2 Cognitive Neo-Associationistic Model .................................................... 85 3.3.3 Social Cognition Perspective .................................................................... 87 3.3.3.1 Social Learning .......................................................................... 87 3.3.3.2 Causal Attribution – Fundamental Attribution Error ................. 90 3.3.4 Excitation Transfer Theory ....................................................................... 90 3.3.5 Social Interaction Theory ......................................................................... 92 3.4 Interim Summary .................................................................................................... 92 3.5 General Aggression Model ..................................................................................... 93 3.5.1 Schemas and Script Theory ...................................................................... 95 3.5.2 Situation and Person Factors as ‘Inputs’ for the GAM ............................ 95 3.5.3 The Process of Aggression According to the GAM ................................. 96 3.5.4 The Cognitive Appraisal Process in the GAM ......................................... 98 3.5.5 Behavioural Outcomes According to the GAM ....................................... 98 3.5.6 Applying Relevant Theory to the Phenomenon of Aggressive Driving ... 99 3.6 Additional Research Questions............................................................................. 101


3.7 Chapter Summary ................................................................................................. 102


3.1 Introduction

In order to examine aggressive driving from an informed theoretical perspective

and to explore potential personal/psychosocial differences that may characterise

aggressive drivers, it is prudent to consider theories used to explain human aggression in

other contexts. This chapter will review current psychological theories used to explain

human aggression. Following an overview of each theory, this review will briefly assess

the potential applicability of each theory to aggressive driving. These theories have

been amalgamated in a model of human aggression i.e. the general aggression model

(GAM) (Anderson & Bushman, 2002). This model will be proposed as the guiding

framework for exploring aggressive driving in this research.

Although the theories outlined provide psychological explanation for why

aggression occurs in particular contexts, discussion of the theoretical basis of aggression

would be incomplete without examining other factors known to influence the

development of aggressive tendencies. It is widely accepted that during the years of

human development, exposure to a range of risk factors increases the likelihood of

developing aggressive tendencies (Farrington, 1991, 1999; McDonald & Brown, 1997;

NCV, 1990). Such tendencies appear to predispose an individual to respond

aggressively in the face of perceived provocation. Therefore, a brief review of

potentially significant risk factors is included.

At the outset it is noted that not all aggressive behaviour should be viewed in a

negative manner. Indeed, a certain amount of aggression is needed in order for species

to survive and for human beings to assert themselves in constructive ways (Geen &

Donnerstein, 1998; Renfrew, 1997). Nonetheless, within the driving context aggressive

actions can have significant impacts on other road users.

3.1.1 Types of Human Aggression

Within human aggression research many dichotomous descriptors have been

used to label behavioural outcomes, such as instrumental/hostile and proactive/reactive

aggression. These subtypes are based on the assumption that not all aggressive

behaviour has detrimental effects. Most of the definitions primarily distinguish between

instrumental, controlled aggressive behaviours and impulsive, hostile behaviours

(Vitiello & Stoff, 1997). For example, the distinction can be made between asserting


one’s self to achieve a goal, versus physical violence. In human aggression research,

however, a distinction is often made between pre-meditated and impulsive/reactive

aggression, distinguishing between intentional and unintentional acts respectively

(Barratt, Stanford, Dowdy, Liebman, & Kent, 1999; Stanford, Houston, Mathias,

Villemarette-Pittman, Helfritz, & Conklin, 2003).

Another distinction made in research concerning the psychology of human

aggression is that instrumental aggression is not often associated with strong emotional

triggers. However, more extreme, hostile aggression is associated with strong emotions,

namely anger or fear. Research has also suggested that behavioural responses based in

strong emotion are often impulsive and therefore, they have termed such behaviour as

‘reactive’ aggression (Dodge & Coie, 1987). These researchers also maintain that the

increased arousal levels associated with high emotion reduce the number and/or quality

of cognitive strategies available, possibly reducing the ability to inhibit the expression of

aggression.

In the context of aggressive driving, Shinar (1998) offered a dichotomous

representation of on-road aggression that had been based in frustration-aggression theory

(Dollard et al., 1939). As discussed in Section 2.1.7, he maintained that drivers either

engage in instrumental, constructive behaviours aimed at overcoming an obstacle or

source of frustration, or they engage in hostile aggression aimed at physically or

psychologically harming another driver. Hostile aggressive behaviours are believed to

stem from strong feelings of frustration/anger, whilst instrumental behaviours are less

emotional and more goal oriented.

In aggressive driving behaviour, there appears to be a consistent emotional

trigger to an on-road incident, i.e. frustration/anger. This emotion has been found to

precede a range of on-road, aberrant behaviours repeatedly considered as aggressive

driving, such as speeding, overtaking, tailgating and cutting-off (Lajunen & Parker,

2001; Shinar, 1998; AAA, 2008; NHTSA, 2000; VCCAV, 1999). Further, in keeping

with the findings of Dodge and colleague (1987), the on-road experience of such high

emotion increases arousal levels whilst incapacitating cognitive function within an

already cognitively demanding environment, therefore, potentially further reducing the

ability to inhibit aggressive behaviour. At such times, highly aggressive drivers may


deviate from their original aim/goal for driving in order to express such emotion.

However, lesser on-road behaviours, whilst perceived as aggressive by some, may not

generate sufficient emotion to warrant a deviation from the original goal.

Consequently, in terms of on-road aggression, this thesis considers aggressive

driving to be typically reactive aggression, as it appears to typify a basic assumption

underlying on-road aggression. That is, most aggressive driving behaviours are believed

to be a reactive response to other stimuli/triggers. In consideration of the range of on-

road behaviours that have been identified as potentially aggressive on-road behaviour,

they appear to occur on a scale of increasing severity from low level to highly reactive,

aggressive behaviour. Therefore, in keeping with Shinar’s distinction and the emphasis

on goal directed behaviour this thesis will further distinguish between instrumental (goal

directed) and hostile (goal-postponing) aggressive driving behaviour.

3.2 Developmental Risk Factors for Aggression

Researchers agree that there are multiple pathways to aggression. Upon each of

these paths an individual’s predisposition for aggression is influenced by multiple

factors. The factors include biological, neurophysiological/neurological, developmental

and social influences. Biological factors, or the contribution of genetics to aggression,

have been established through heritability and twin studies (Bergeman & Montpetit,

2003). The study of neurochemistry and aggression has identified the importance of

serotonin and testosterone levels (Eichelman, 2003). Neurological evidence for

aggression has been established with identification of higher levels of aggression being

associated with frontal lobe damage and brain lesions (Eichelman, 2003). Further, there

is substantial evidence for the influence of social and developmental factors, such as

peer group associations, characteristics of the family of origin and exposure to violence

(Borum, 2000; Caspi, 2000; Coccaro, Berman & Kavoussi, 1997; , 2003; Farrington,

1991, 2000; Farrington, Loeber, Yin, & Anderson, 2002; Loeber, Farrington,

Stouthamer-Loeber, Moffitt, Caspi, & Lynam, 2001). However, considering the

psychosocial emphasis of this research, the following literature review will focus on the

social and developmental risk factors that have been associated with an increased

likelihood for aggressive behaviour.


Though the aforementioned pathways are distinctive, it is widely accepted that

the co-existence of two or more of the elements from differing paths, increases the

likelihood of the development of aggressive and/or violent tendencies (Coccaro et al.,

1997). Suffice to say, there is no one clear path for the development of aggression.

Importantly, longitudinal research has linked criminal activity or antisocial behaviours at

age 30 with peer-reported aggression levels at age eight (Huesmann, Eron, Lefkowitz, &

Walder, 1984). These findings have been supported by other longitudinal research

studies that consistently report the relationship between childhood aggression and young

adult aggression, antisocial and delinquent behaviour, and/or criminality (Farrington,

2000; Farrington, 2004). In Australia a large longitudinal study of Queensland children

(n = 7,600) conducted by the Mater Hospital, Brisbane, reported the significant

prediction of delinquency at age 14 by parent and teacher reported levels of aggression

at age five (Bor, Najman, O’Callaghan, Williams, & Anstey, 2001). These researchers

also found that 48% of children that scored in the top 10% of the Child Behaviour Check

List (CBCL) aggression subscale, also scored in the top 10% of the delinquency scale.

Early traffic researchers suggested a simple truism that man drives as he lives

(Tillman & Hobbs, 1949). Consistent with this thinking, Elliott (1999) suggested that

extreme cases of aggressive driving or ‘road rage’, are a reflection of deeper criminal

tendencies that reflect a driver’s preparedness to engage in illegal behaviours. Further,

in an extensive review of risk factors for aggression conducted by the Australian

Institute of Criminology, aggressive children were found to become aggressive teenagers

who, in turn, become aggressive adults (McDonald & Brown, 1997).

For the purpose of this research the risk factors for aggression are discussed

under two broad headings: historical factors, and clinical factors. In this instance,

historical factors refer to the personal factors one is exposed to across time that may

predispose an individual to the development of aggressive tendencies. These factors

include personal exposure and/or history of violence and delinquent behaviours,

schooling difficulties, negative peer group influences and familial history of aggression

and violence. Clinical factors include long or short-term identification with a clinical

issue or disorder such as conduct disorders, substance abuse disorders, high impulsivity,


emotional regulation difficulties, and negative attitudes including hostile attribution bias,

and exposure to significant life stressors.

3.2.1 Historical Factors

3.2.1.1 Personal History of Violence and Delinquency

A history of prior violent behaviour has been found to be the strongest single

predictor of future violence (Farrington, 1991). Further, the risk of future violence

increases incrementally according to the number of prior episodes (Farrington, 1991).

Specifically, prior arrest for violent criminal/delinquent acts increases the likelihood of

subsequent violent acts (Parker & Asher, 1987). Less ‘violent’ acts that are considered

anti-social, such as stealing, property damage, smoking and drug dealing are also linked

to later violence in males (Hawkins, Herron Kohl, Farrington, Brewer, Catalano, &

Harachi, 1998). The earlier and more frequent the individual initiation to violent

offending, particularly before age 14, the greater the likelihood of future violence,

involving more chronic and serious acts (Farrington, 1991).

3.2.1.2 Family of Origin

Evidence suggests that the family of origin has a significant impact upon the

development of aggressive tendencies. For instance, family attitudes to schooling,

authority figures and ethnic or minority groups influence a child’s development of

similar attitudes (NCV, 1990; McDonald & Brown, 1997). Much of the research

reviewed in these two reports supports the idea of attitudes transferring across

generations. Specifically, higher levels of negativity on such issues have been found to

be associated with greater violence towards minority groups and authority figures (NCV,

1990). This is achieved through the adoption of hostile attributions and deviant norms

(Dodge, Price, Bachorowski & Newman, 1990; Vaughan & Hogg, 1995). Similarly,

therefore, poor familial attitudes to schooling may increase the likelihood of low-school

achievement, high truancy levels and difficulty with authority figures.

Parenting styles have also been found to impact upon the likelihood of

aggression, delinquency and violence. The rejection of a child by their parents, strong

parental agreement with use of punishment and parental history of delinquency have

been found to be significant predictors of violent crime by age 30 (Huesmann, Eron, &

Dubow, 2002). Poor parent/child communications have also been found to be


significantly associated with adolescent delinquent behaviour and aggression (Fagan &

Najman, 2003). This study also found that the adolescent delinquent behaviour of one’s

siblings may influence the likelihood of delinquent behaviours at age 14. This influence

was particularly strong for males whose parents had also been arrested (Fagan &

Najman, 2003).

Other research suggests that children exposed to marital discord or family

violence are likely to be aggressive and participate in anti-social behaviours at age 14

(Bor, McGee, & Fagan, 2004). This research conducted by the Mater Hospital in

Brisbane has found that within the family of origin marital instability can double (or

even triple) the odds of anti-social behaviour in children. As adults, such individuals

may be more likely to participate in domestic violence themselves, as several bodies of

research have found associations between marital discord, partner-directed violence and

a likelihood of a youth engaging in violence (Dahlberg, 1998).

In other research, 14-year-old delinquent adolescents were significantly more

likely to be from middle to low income families and originate from poor housing (Bor et

al., 2001; Farrington, 2003). However, the influence of household income upon the

development of aggression and other anti-social behaviours is complicated by the

limitations that a low income can have upon the necessity to live in poorer

neighbourhoods.

3.2.1.3 Victims of Abuse

Widom and colleagues (1995) found ‘abused/neglected’ children have more

arrests for delinquency, criminality and violent criminal behaviour than a matched

control group. However, his 1998 research suggested that victims of ‘sexual abuse’

were slightly less likely than a no-sex abuse control group to commit violent offences

(Widom, Ireland & Glynn, 1995; Widom, 1998). Neglect in the form of low levels of

love, care, interest and/or attachment to a child has also been linked to delinquency

(Mak & Kinsella, 1996). Further, it seems that if they do commit offences earlier in life,

they often become repeat offenders (Widom, 1998).

Other research has also found that such experiences predispose an individual to

violent or criminal acts via the provision of less than ideal role models, and the

reinforcement and rewarding of violent or criminal behaviours (Klassen &


O’Connor,1994). Where neglectful parenting is present, young individuals may be more

readily influenced by negative peer group membership. Within these groups troubled

young people may find belonging, acceptance and rewards for participation in

delinquent behaviours (Klassen & O’Connor, 1994).

3.2.1.4 Negative Peer Relations

The single best predictor of adolescent behaviour, in general, has been found to

be the behaviour of close friends (Werner-Wilson & Osnat, 2000). Generally, peer

relations have a positive impact upon the development of interpersonal, social and

emotional competence (Dahlberg, 1998). However, they can also have a negative

impact if the group tends to engage in risk-taking behaviours (Dahlberg, 1998) or if the

group rejects an individual (Borum, 2000). With reference to the latter, the National

Committee on Violence (NCV, 1990) observed that delinquent groups, in particular,

appear to provide a refuge for rejected youth, where they are able to develop a sense of

belonging and identity. Hence, if an individual’s family and peer group reject them, the

greater the potential for negative impact.

Aggressive children tend to associate with each other in anti-social ways

engaging in risky/delinquent behaviours (Cairns, Neckerman, Gest, & Gariepy, 1988).

Though gang violence is relatively rare in Australia, association with delinquent peers

increases the risk of serious delinquency and criminal activity (NCV, 1990).

3.2.1.5 Schooling Problems

Young people with low school achievement and conduct problems at school have

been found to be more likely to participate in delinquent behaviours and in turn be

involved in criminal behaviour (Hawkins et al., 1998; Farrington, 2002). However, in

Farrington’s 2002 study, he found that the contribution of low school achievement and

conduct difficulties to later delinquency/criminal behaviour is indirect. A number of

factors are known to influence both of these, such as poor family experience, low IQ,

impulsive/aggressive tendencies and subsequent poor attributions for those in authority,

e.g. teachers (Farrington, 2000; Huesmann, Eron, & Dubow, 2002; Loeber et al., 2001;

Watson, Fischer, Andreas, & Smith, 2004).

In a longitudinal study spanning 14 years, researchers have found that the

symptoms associated with DSM-IV conduct disorders (CD, ADD, ADHD and ODD),


characterised by externalising behaviours, are significantly related to the development of

aggressive tendencies (Loeber et al., 2001). These researchers emphasised that

conductive disorders have both cognitive and behavioural manifestations, such as high

impulsivity and disruptive behaviour in the classroom. Additionally, such behaviours in

the youngest group (ages spanning 7–13 years) predicted aggressive behaviours,

delinquency and psychopathy prevalent as adults aged 20–25 years (Loeber et al., 2001).

Australian specific research has also revealed school reported aggression levels

at age five are significantly predictive of delinquency at age 14, as measured by the

number of suspensions from school (Bor et al., 2001).

3.2.2 Clinical Factors

3.2.2.1 Substance Abuse

The following is an extension of the discussion of alcohol/drug consumption as

an influencing factor in driving behaviour (see Chapter Two, p. 58). However, the

emphasis in this section is on the influence of substance abuse upon the development of

general human aggression.

In their review of risk factors for aggression, researchers have reported that

alcohol use is associated with increased rates of aggression and violent crime,

particularly in younger individuals 18-24 years of age (McDonald & Brown, 1997;

Taylor & Hulsizer, 1998). Other research into motivations for alcohol use has found

that there may be two distinct motives for alcohol use (Cooper, Frone, Russell, &

Mudar, 1995). Using structural equation modelling these researchers found that

individuals either drink in order to engage in, or enhance, social interaction within their

social group, or they use alcohol as a way to ‘cope’ in the absence of other

constructive/adaptive ways of coping. They also highlighted that the latter motivation

for alcohol consumption is strongly associated with negative emotionality (as measured

by levels of depression) (Cooper et al., 1995). Evidence of the validity of these two

motives was established across two samples: an adolescent sample (mean age 17.4

years), and an adult sample (mean age 41.8).

Though the link between illicit drug use and aggression has not been

conclusively established (Taylor & Hulsizer, 1998), researchers believe that the

relationship between aggression and illicit drug use may be a by-product of the


necessary association with illegal markets or criminal sub-cultures (NCV, 1990).

Longitudinal research has found that illicit drug use during early adolescence is

associated with concurrent and later delinquency (Brook, Whiteman, Finch, & Cohen,

1996).

Intoxicating amounts of alcohol are believed to reduce inhibitions and effect

social and cognitive functioning. Social interaction may become confused, increasing

the potential for inappropriate responses and increasing the possibility of aggression

(NCV, 1990).

3.2.2.2 Attitudes

Specific to aggression, saturation with negative thought patterns through

negative family or peer associations may support the early development of beliefs and

thought patterns supportive of aggression (Dahlberg, 1998). For instance, negative

stereotypes are known to influence attitudes towards others and increase the likelihood

of aggressive behaviour to them (Vaughan & Hogg, 1995). Also, negative perceptions

of provocation or intentionality by others may influence behavioural outcomes

(Vaughan & Hogg, 1995; Verona, Patrick, & Lang, 2002).

Research into positive self-view with regard to aggressive children has found that

aggressive children (mean age 7.6 years) tended to have inflated or idealised views of

themselves in terms of their self-rated competency at relationships and the quality of

those relationships (Hughes, Cavel, & Grossman, 1997). Other research has examined

the role of high self-esteem, in egotism, violence and aggression (Baumeister, Smart, &

Boden, 1996).

As briefly discussed in Chapter Two (Section 2.2.7), this interdisciplinary review

of aggression, crime and violence clearly illustrates that high self-esteem, or egotism, is

more commonly associated with aggression and violence, than low self-esteem

(Baumeister et al., 1996; Baumeister, Bushman, & Campbell, 2000; McFarlin &

Blascovich, 1981). According to these researchers, high self-esteem combined with a

perceived threat to the ego leads to aggression. If the favourable view of one’s self is

questioned or challenged, people may be more likely to adopt aggressive strategies

(Baumeister et al., 1996). This review also highlighted that individuals with unstable

self-appraisal seem to become sensitive and defensive, such that in the face of negative


social feedback they are more likely to have hastier and more intense responses than

people with stable self-appraisal.

Negative emotional affect also serves a pivotal intervening role to the expression

of aggression (Berkowitz, 1989; Dollard et al., 1939). Hence, in the face of a challenge

to ego or self-esteem, an individual may experience strong negative emotion (not

exclusively anger) and seek to dispel or rebut such a challenge with aggressive or

defensive behaviours (Baumeister et al., 1996). Very high self-esteem, or narcissism,

has also been associated with psychopathic individuals, with such individuals being

associated with aggressive behaviour (Hare, Harper, Hakstian, Forth, Hart & Newman,

1990). These individuals are not socially sensitive i.e. sensitive to the needs or concern

for others, however, they remain aware or concerned with their own ego (Baumeister et

al., 1996). They also appear to lack remorse for socially unacceptable behaviour (Hare

et al., 1990). Indeed, many perpetrators believe their aggressive responses are justified,

taking a moralistic stance against the perceived provocation (NCV, 1990).

3.2.2.3 Emotional Regulation Difficulties

Though emotional reactivity may be a by-product of perceived challenges of

self-esteem, it is not the only cause of emotional reactivity. Much research shows that

difficulty regulating emotions may develop across the course of one’s life and may

contribute to aggressive tendencies (Berkowtiz, 1993; Dollard et al., 1939).

In the Pittsburgh Youth longitudinal study of male mental health problems,

psychopathology and personal traits, levels of physical aggression were examined

(Loeber et al., 2001). The level of physical aggression remained reasonably constant

between the ages 6–17 years. These researchers also distinguished between internalising

and externalising behaviours and aggression. Of the internalising behaviours examined,

only depressed mood at middle age was correlated with initiation of offending behaviour

(Loeber, Stouthamer-Loeber, Van Kammen, & Farrington, 1991). Externalising

behaviours that signify difficulties in regulating emotions, were also examined. These

included physical aggression levels, mental health problems and disruptive behaviour

disorders that may lead to later delinquency. Aside from the identification of multiple

conduct disorders in aggressive 6–17 year olds, these disorders were found to be

significant predictors of serious, stable anti-social behaviour in adolescents over other


known predictors (Loeber et al., 1991). Like others, these researchers also emphasised

the role of emotion in psychological maladjustment and, specifically, the possible

consequences of negative emotionality (Chang, Schwartz, Dodge, & McBride-Chang,

2003; Cummings, Goeke-Morey, & Papp, 2004; Loeber et al., 1991).

A study of 17-year-old twins revealed that in both male and female adolescents,

parental history of alcohol abuse was associated with greater negative emotionality,

aggression and stress reactions (Elkins, McGue, Malone, & Iacono, 2004). Adolescents

from such backgrounds had lower levels of personal constraint and control as measured

by the Multi-dimensional Personality Questionnaire (MPQ) (Tellegen & Waller, 2008).

Another experimental study revealed that when individuals high on negative

emotionality (measured by the negative emotionality scale of the MPQ) are exposed to

strong airblasts, they become more aggressive than participants low on negative

emotionality (Verona, Patrick, & Lang, 2002).

More recently researchers examined the impact of everyday marital conflict and

levels of aggression in children aged 8–16 years (Cummings, Goeke-Morey, & Papp,

2004). These researchers found that exposure to personally destructive conflict tactics

and parental negative emotionality increases the likelihood of aggressive behaviour in

children, possibly through the development of emotional regulation difficulties. Harsh

parenting practices have also been found to be associated with the level of aggression

exhibited at school, mediated by the child’s emotional regulation ability (Chang et al.,

2003).

In other research, using different terminology, researchers have examined

emotional susceptibility and irritability and their influence on aggression (Caprara,

Gargaro, Pastorelli, Prezza, Renzi, & Zelli, 1987). Emotional susceptibility reflects a

tendency towards defensiveness and is also associated with a tendency to ruminate

(Caprara et al., 1987; Bushman, Bonacci, Pedersen, Vasquez & Miller, 2005).

Individual irritability is reflected in the tendency to react impulsively and

inappropriately to the slightest provocation (Chang et al., 2003). Both constructs are

believed to be related to an individual’s capacity, or ability, to maintain control over

their emotions (Caprara et al., 1987). Caprara and colleagues (1987) compared the two

constructs and found that emotional susceptibility and the tendency to ruminate were the


best predictors of delivering shocks at different levels of intensity. They found no sex

differences.

Finally, in a longitudinal study, researchers have demonstrated that negative

emotionality is a trait state that has the ability to persist across time (Murphy, Shepard,

Eisenberg, & Fabes, 2004). This study found that children low on social functioning at

ages four and six years, possessed higher levels of negative emotionality and lower

emotional regulation abilities at age 10 and 12 years, than were those originally high on

social functioning (Murphy et al., 2004). Hence, the foregoing research would suggest

that without positive influences (e.g. positive peer groups or positive parenting)

dysfunctional levels of negative emotionality may persist and compound across time.

3.2.2.4 High Impulsivity

High impulsivity has long been identified as a key indicator for a number of

diagnosable disorders (e.g. Attention Deficit Hyperactivity Disorder – ADHD, Attention

Deficit Disorder – ADD, Obsessive Compulsive Disorder – OCD, Oppositional Defiant

Disorder – ODD and Anti-social Personality Disorder – ASD). Further, those diagnosed

with these disorders have frequently been characterised with aggressive tendencies and

greater risk-taking behaviour (Bor, 2004; Fossati, Barratt, Caretta, Leonardi, Grozioli, &

Maffei, 2004; Iacano, Carlson, Taylor, Elkins, & McGee, 1999; Volavka & Citrome,

1998).

Researchers have noted that children with conduct problems often have

emotional regulation difficulties (Frick, 2004; Bushman, Baumeister, & Phillips, 2001).

Such emotional regulation problems often find the child experiencing ‘anger’ in

response to perceived provocation which in turn results in impulsive and unplanned

aggressive acts (Pardini, Lochman, & Frick, 2003). These children were also likely to

experience continued difficulty controlling their future responses (Pardini et al., 2003).

Impulsivity has also been associated with ‘irritability’, considered a trait stress

pre-disposition to react impulsively to the slightest perceived provocation (Caprara et al.,

1987; Stanford, Greve & Dickens, 1995). In a short-term longitudinal study researchers

have examined the relationship between impulsivity and anti-social behaviours such as

rule breaking, vandalism, theft, aggression and drug-taking (Luengo, Carillo-de-la-Pena,

Otero, & Romero, 1994). Collecting data in 1989 and again in 1990 from 1,226


adolescents, they found that impulsivity, as opposed to ‘irritability’, is closely associated

with these behaviours. Their results also found that high impulsivity (as measured by

the Barratt Impulsiveness Scale - BIS) is associated with future anti-social behaviours,

including aggression (Luengo et al., 1994). However, other researchers have found that

impulsivity and irritability (measured by the Buss-Durkee Hostility Inventory - BDHI)

both have a relationship to aggression (Patton, Stanford, & Barratt, 1995). High scores

on BIS impulsivity and BDHI irritability were significantly correlated with the self-

reported number of impulsive aggressive episodes in the previous month (Stanford et al.,

1995).

The link between impulsivity and aggression has also been explained by

inhibition deficits. In a sample of 84 university students (16 males and 68 females,

mean age 23.7) such deficits have been found to have a moderate to strong relationship

with the ‘anger’ subscale of the AQ (Buss & Perry, 1992; Vigil-Colet & Colormiu-Raga,

2004).

When examining impulsivity and its relationship to aggression, other researchers

have focused on the differences between reactive and proactive aggression (Connor,

Steingard, Anderson, & Melloni, 2003). In such research, reactive aggression is

considered anger or defensive behaviour in response to a perceived provocation or

frustration. Conversely, proactive aggression is deliberate, controlled behaviour used to

achieve a desired goal (Coccaro, 2003). Following this distinction, researchers found

hyperactivity/impulsivity to be correlated with reactive aggression, especially in males

(Connor et al., 2003).

The latest version of the BIS (BIS – 11) has three first order factors: motor

impulsivity, non-planning, and attentional impulsivity comprising two second order

factors – ‘attention’ and ‘cognitive instability’. Using the BIS researchers have studied

the relationship between impulsivity and aggression. In a study of 592 students (mean

age = 22) those who scored highly impulsive on the BIS were more involved in risk-

taking behaviour including drink/drug driving and aggression (Stanford, Greve,

Boudreaux, Mathias, & Brumbelon, 1996).

Other research has linked aggression with high sensation seeking and impulsivity

(Joireman, Anderson, & Strathman, 2003). These researchers considered that sensation


seeking and impulsivity are related as both constructs are concerned with immediate

gratification rather than with consideration of future consequences (CFC). The

sensation seeking/impulsivity subscale of the Zuckerman-Kuhlman Personality

Questionnaire (ZKPQ) (Zuckerman, Kuhlman, Joireman, Teta, & Kraft, 1993) was

found to have an inverse relationship with CFC. Though both sensation seeking items

and impulsivity items on this scale were significantly correlated with CFC, impulsivity

items correlated more closely with CFC (Joireman et al., 2003). This study also

suggested that hostile cognitions and negative emotions may mediate the relationship

between sensation-seeking/impulsivity and aggression.

Using the BIS and the AQ in a study of premeditated versus impulsive

aggression, impulsive aggression was found to be characterized by ‘thought confusion’

(BIS measured) and post-incident feelings of remorse (Barratt, Stanford, Dowdy,

Liebman, & Kent, 1999). Not surprisingly, other research has found impulsivity to be

significantly but negatively correlated with social problem solving (D’Zurilla, Nezu, &

Maydeu-Olivares, 2002; McMurran, Blair, & Egan, 2002). These researchers suggest

that higher levels of impulsivity throughout development may leave an individual with

social problem solving deficits, or deficits in social information processing. Therefore,

impulsivity has an influence on cognitive functioning which in turn can result in

spontaneous and often aggressive expression.

A similar suggestion has been made in other research that focused on the

relationship between impulsivity and a larger range of higher order cognitive functions

such as attention, planning, abstract reasoning, mental flexibility and self-monitoring

ability (Hoaken, Shaughnessy, & Pihl, 2003). These researchers have yielded results

that suggest social information processing mediates the likelihood of these higher order

functions translating into aggressive behaviour.

3.2.2.5 General Life Stressors

Further to the familial and peer stressors discussed above, there are a number of

stressors that may influence the development of aggressive tendencies or clinical

disorders that have aggression as a characteristic. Importantly, these events would need

to be perceived as quite significant and stressful in order for an individual to be

psychologically or adversely affected. Evidence suggests that the more extreme, or


psychologically demanding an event is, combined with the availability of fewer problem

solving resources, the greater the risk of negative impact by the stressor (Goodman,

Corcoran, Turner, Yuan, & Green, 1998; Stamm, Rudolph, Dewane, Gaines, Gorton,

Paul, McNeil, Bowen, & Ercolano, 1996).

In 1995 a study of 276 Israeli army recruits (n = 276) examined appraisal and

coping in stressful situations. Specifically, they found higher levels of ‘hardiness’

(consisting of measures of commitment and control) improved mental health at the end

of recruit training by reducing the frequency of threat appraisal and use of emotion-

focused strategies (Florian, Mikulincer, & Taubman, 1995).

As discussed in Chapter Two (Section 2.5.8.1), stressful life events have been

previously assessed in their ability to influence driving outcomes (Navaco et al., 1990).

However, clinicians have also designed scales for the purpose of establishing potentially

significant life events upon the assessment and/or intake of clients. Assessments of this

nature are considered important not only clinically, but for research purposes, as such

significant events have the potential to confound assessments and research results

(Stamm et al., 1996). The immediacy or currency of such events is also highly relevant

as the passage of time may reduce the negative physiological and psychological affects.

Consequently, it is important to consider the individual background of each participant

when studying aggression in any context.

3.2.3 Psychological Impact of Risk Factors

The negative impact of the foregoing risk factors is experienced via two

pathways. Firstly, via the short-term or immediate experience of higher physiological

and emotion stress levels. However, if the event was profoundly violent or aggressive,

or is frequently repeated, this may alter long-term reactions to provocative situations.

Human aggression research has found that through prior exposure to prolonged periods

of stress and/or environmental threats such as physical or sexual abuse (Nash, Hulsey,

Sexton, Harralson & Lambert, 2000) or post-traumatic stress disorder (PTSD) (Silva &

Marks, 2001) an individual may have a heightened tendency to detect potential ‘threat’

within their environment. Additionally, in response to an ambiguous though provocative

situation, aggressive children have been found 50% more likely to infer hostile intent

(Dodge & Coie, 1987). This hostile attribution bias is associated with the subsequent


displays of hostile rather than instrumental aggression (Dodge & Coie, 1987). Highly

aggressive children also have difficulty diverting their attention away from such cues

(Dodge & Coie, 1987).

The period, or point in time, in human development that one is exposed to such

events is also relevant. The findings associated with these risk factors would suggest

greater, long term, negative impact by them when initially exposed during childhood and

early adolescence. In keeping with frustration-aggression theory (Dollard et al., 1939),

such events may serve to reduce one’s frustration threshold, increasing the likelihood of

aggression in the face of provocation. Consistent with the cognitive and social learning

theories embedded in the GAM (Bushman & Anderson, 2001), exposure to these risk

factors provides the opportunity for the formation of aggressive or emotional schemas.

As a result, an individual’s inability to regulate their emotional reactions in threatening

or provocative situations may be more likely.

3.3 Psychological Theories Relevant to Aggressive Driving

This review will focus upon social and bio-social explanations of aggression,

which emphasise the learning processes of aggression and causal factors within social

contexts. As the preferred approach for many psychologists, these theories maintain that

instinctive drives (or states of arousal) and learned behaviour underlying human

aggression can be unlearned (Tedeschi & Felson, 1994; Vaughan & Hogg, 1995).

Therefore, these theories may enhance our understanding of the psychology behind

aggressive driving behaviour, informing the development of effective education

packages for the general population, and rehabilitation strategies for court-referred

offenders.

3.3.1 Frustration-Aggression Theory

The original frustration-aggression hypothesis (Dollard, Doob, Mowrer, Miller,

& Sears, 1939) maintains that ‘aggression is always a consequence of frustration’ (p. 1)

and conversely that the existence of frustration or multiple frustrations always leads to

aggression in some form, whether it be suppressed, disguised or delayed from the

obvious goal or source of frustration i.e. displaced (Dollard et al., 1939). A frustration is

considered an external condition or factor that prevents a person from obtaining a goal

he or she had expected to attain (Berkowitz, 1989).


Central to this theory is the concept of the frustration-aggression threshold

(Dollard et al., 1939). This concept proposes that increases in frustration lowers an

individual’s ‘aggression threshold’ increasing the likelihood of aggressive behaviour.

Dollard and colleagues (1939) proposed that frustration builds in a cumulative sense

from multiple sources, increasing the likelihood of aggressive behaviour if an individual

is continually provoked. They also maintained that the expression of the frustration or

anger serves a cathartic purpose, returning the frustration-aggression threshold to its

‘normal’ level. The frustration-aggression threshold may not only assist in our

understanding the likelihood of aggressive behaviour, but may also assist in explaining

the proposed accumulation of frustration and its subsequent ‘displacement’ as

aggression to subsequent points in time (Dollard et al., 1939).

Much research has been conducted into displaced aggression since its inception

within the original frustration-aggression theory (Dollard et al., 1939; Marcus-Newhall,

Pedersen, Miller, & Carlson, 2000). A meta-analysis of this phenomenon illustrated the

robust nature of displaced aggression (mean weighted effect size = +.54) (Marcus-

Newhall et al., 2000).

In one such study, participants were either exposed to an anger-provoking event

or not, and this exposure was followed by an unrelated, trivial trigger (Pedersen,

Gonzales, & Miller, 2000). For those that had been provoked, exposure to the trivial

trigger strongly increased displayed aggression levels, even exceeding the aggression

displayed in response to provocation alone (Pedersen, Gonzales, & Miller, 2000).

The original frustration-aggression theory also maintained that high levels of

frustration will, invariably, result in aggression (Dollard et al., 1939). In a reformulation

of frustration-aggression theory, Berkowitz (1983), however, maintained that aggression

will only result if the frustration or an aversive event is ‘unpleasant enough’ to produce

strong negative affect, such as ‘anger’.

3.3.2 Cognitive Neo-Associationistic Model

As outlined above, Berkowitz (1993, 1988, 1989, 1990) contributed substantially

to the further development of frustration-aggression theory (Dollard et al., 1939).

Building upon the original frustration-aggression theory tenets, Berkowitz formulated

the ‘cognitive neo-associationistic’ model of aggression, which emphasises the cognitive


contribution to the experience of intense emotions and its influence on the likelihood of

aggressive behaviour (Berkowitz, 1989, 1990, 1993). In this theory, when faced with

aversive, unpleasant events or physical discomfort in the form of high temperatures or

loud noise, basic instincts and thoughts to fight or take flight are activated (Berkowitz,

1993). These basic instincts result from feelings of ‘anger’ in the case of ‘fight’, or

‘fear’ in the case of ‘flight’ (Berkowitz, 1989, 1990, 1993).

Berkowitz (1993) maintains that these initial, virtually automatic feelings and

thoughts can be accompanied by expressive motor-responses, or reactions. Factors such

as prior learned responses to threatening or anger provoking situations, situational

factors and individual trait dispositions for aggression add to these initial feelings,

determining the strength of the inclination to fight or take flight (Berkowitz, 1993). The

resultant emotions are influenced at a deeper level of processing via the cognitive

evaluation/appraisal of attributions made about the threatening or anger provoking event,

the potential consequences, internalised rules of behaviour and pre-learned mental

responses established by life experiences i.e. nodes (Berkowitz, 1993).

This model suggests that bodily reactions/responses and emotional thoughts

activate networks of emotionally linked thoughts and mental schemas that reside in the

psychological construct, ‘memory’ (Berkowitz, 1990). In his theory, memory is treated

as a series of networks that consist of ‘nodes’ (Berkowitz, 1993). Each node can include

a number of thoughts and related emotions connected via linked associative neural

pathways. When a thought is activated it radiates outward along the associated

pathways activating other nodes concerning memories and/or related emotions, which

can lead to an increased probability of aggressive behaviour due to ‘priming’

(Berkowitz, 1984). The concept of ‘priming’ may be important when considering the

contribution of off-road stressors, as primers, to on-road aggressive behaviours

(Parkinson, 2001).

In summary, this rather complex process leads to the differentiation, suppression

or enhancement of feelings of annoyance, irritation, anger or fear resulting in

instrumental, or hostile behavioural responses (Berkowitz, 1990, 1993; Parkinson,

2001). Therefore, Berkowitz’ reformulation of the original frustration-aggression theory

appears to offer a framework for the potential contribution of cognitive processes to


aggressive driving outcomes. This model’s emphasis on the cognitive evaluation of a

situation may explain the potential for a thwarted driver to not have an aggressive

response as found in previous research (Lajunen & Parker, 2001).

In a study using the scenario of a car unnecessarily delayed at lights due to the

actions of another driver, the characteristics of the ‘offending driver’ were manipulated.

This study found that feelings of anger and subsequent behavioural reactions are

moderated or enhanced by the characteristics of the ‘offending driver’ such as age and

gender (O’Brien, Tay, & Watson, 2005). It was also found that higher levels of self-

reported anger were not invariably associated with an aggressive driving response in

keeping with the cognitive neo-associationistic model (Berkowitz, 1993). In addition,

Berkowitz’s aggression research highlights the relative importance and potential

influence of internalised processes in aggressive driving outcomes. These processes

involve an individual’s subconscious and/or conscious cognitive appraisal of a situation,

and the associated activation of linked emotional and behavioural nodes i.e. social

cognition.

3.3.3 Social Cognition Perspective

How human beings process information in a variety of social settings has long

been the focus of social and cognitive psychologists. Drawing on the principles of

computer logic concerning the inputs, internalised processes and outcomes, researchers

have focussed on the psychological modelling of various social behaviours and the

psychological constructs which support them, such as ‘memory’ (Bushman & Anderson,

1998). This approach to the study of behaviour has been broadly termed ‘social

cognition’, and at times more specifically ‘social information processing’ (SIP) (Geen &

Donnerstein, 1998).

Within the scope of this review it is not possible to address all of the social

information processing principles that have been used to explain social behaviours.

Therefore, emphasis will be given to those principles that appear to have the strongest

relevance to aggressive driving research.

3.3.3.1 Social Learning

A major theme in social cognition concerns learned behaviour, or social learning

principles (Bandura, 1977; Bushman & Anderson, 1998). Social learning theory


suggests that a person’s behaviour in any given situation is learned both directly through

personal experiences and vicariously through the observation of others or by modelling

the behaviour of others (Bandura, 1977). This learning is believed to be stored in

‘memory’ as a set of mental representations called schemas/scripts, not dissimilar to the

‘nodes’ in Berkowitz’ (1993) cognitive neo-associationistic theory. These scripts are

believed to contain images of past events and behaviours which may be associatively

linked with other schemas/scripts (Bandura, 1977; Huesmann, 1988). The activation of

these scripts within a social setting is known as ‘social cognition’. Social cognition is

believed to be the mediating process between situational factors and resultant social

behaviour. To date, a number of social-cognitive researchers have explored the

‘appraisal’ processes in which an evaluation is made of a situation (Berkowitz, 1993;

Huesmann, 1988; Yagil, 2001).

Appraisal of a situation involves cognitive evaluations of the unpleasantness of

the event (Berkowitz, 1993), the characteristics of others (O’Brien, Tay, & Watson,

2005) and how much attention is to be given to situational cues (Huesmann, 1988). In

sum, when faced with social dilemmas individuals evaluate and interpret situational

characteristics, either consciously or subconsciously, by searching available memory

schemas/scripts for previously learned guides to behaviour (Huesmann, 1988). Once the

schemas/scripts are located they are evaluated, potential consequences are assessed and

a behavioural outcome results (Bushman & Andersen, 1998; Huesmann, 1988).

In terms of aggressive behaviour, to date, SIP research appears to have

emphasised the social influences on aggressive behaviours i.e. situational factors that

either enhance or inhibit the likelihood of aggressive behaviour (Huesmann, 1988;

Yagil, 2001). In aggressive driving research such factors would include

presence/absence of passengers, anonymity and type of vehicle as a social statement to

name a few. However, SIP in general, appears to lack emphasis on individual

differences such as personality, current mental state and the variation in behaviour that

can result (Bushman & Anderson, 1998). Consequently, this appears to limit the ability

of SIP processes alone to explain the aggressive behaviour of individuals.

Importantly, aggression research involving SIP includes an explanation for the

impact of stress, mood and subsequent emotional arousal on information processing,


which may prove relevant to aggressive driving research. Arousal due to stress and

mood has been found to negatively influence the cognitive evaluation process (Zillmann,

1988). For example, high levels of hostility have been found to reduce the amount of

attention and evaluation given to a situation (Crick & Dodge, 1994). In addition, high

levels of arousal were found to narrow the memory search and activate only those

schemas/scripts that are closely connected to those cues, resulting in a narrower range of

possible behavioural outcomes being available. Further, when feelings of stress are

coupled with situational cues activating feelings of fear or anger, Berkowitz (1998)

suggests that it is far more probable that only aggressive schemas/scripts will be

activated, resulting in more aggressive behavioural responses (Berkowitz, 1998;

Bushman & Anderson, 1998).

Specific to aggressive driving research, however, Parkinson (2001) found that

those drivers that reported negative affect prior to driving were less likely to report it as

an influencing factor on self-reported levels of anger in an on-road situation.

Unfortunately, the sample size of this study was relatively small (n=64) and the findings

may be indicative of the difficulties inherent in self-report methods of aggression (Boyce

& Geller, 2002). Therefore, in light of these findings, it would be prudent to revisit on

and off-road generated affect and any subsequent effects on driving behaviour.

Further, in a study of cognitive antecedents to aggressive road behaviour, Yagil

(2001) posited that attributions affect aggressive reactions to another driver’s

provocative road behaviour. Yagil’s study of 150 males found that negative attributions

applied to another driver are likely to increase the amount of driving related frustration

or anger with male ‘offending drivers’ attracting more negative attributions and

emotions than females. Further, such negative beliefs and expectations about another

driver, are more likely to result in evaluations of their behaviour as being inconsiderate

and aggressive (Yagil, 2001). This finding could be considered consistent with the

VCCAV (1999) findings that younger men (aged 18–24 years) are reported three times

more frequently than females as the perpetrators of ‘road rage’ incidents. Therefore it

seems that young male drivers attract more negative attributions about their on-road

behaviour than older drivers. Again, these findings emphasise the need to conduct

further study into the cognitive processes involved in aggressive driving behaviour.


3.3.3.2 Causal Attribution – Fundamental Attribution Error

Social psychologists use the theoretical perspective of Causal Attribution (CA)

when considering the social perceptions of human beings. In CA, individuals assign

characteristics such as emotions or motives to the behaviour of themselves or others.

Further to the aforementioned research into attributions made about driver behaviour

based on gender and age (O’Brien, Watson, & Tay, 2005; Yagil, 2001) additional

research has been conducted into aggressive driving utilising the fundamental attribution

error (Lennon, Watson, Arlidge, & Fraine, in press).

The fundamental attribution error involves attributing the behaviour of others to

some internal cause rather than to situational cues (Vaughan & Hogg, 1995). Lennon

and colleagues (in press) surveyed (n = 193) participants, seeking perceived causes and

effects of the behaviours outlined in a series of scenarios. The results were consistent

with Fundamental Attribution Error (FAE) theory, demonstrating that perpetrators were

significantly more likely to attribute their own behaviour to external, environmental

factors (Lennon, Watson, Arlidge & Fraine, in press). Conversely, this research found

that victims of aggressive driving were more likely to perceive the perpetrators’

behaviours as internal and stable. For example, the perpetrators’ behaviours may have

been perceived as lack of ability or skill at driving.

3.3.4 Excitation Transfer Theory

Another theory that may explain the effects of emotional arousal levels on

driving is Excitation Transfer Theory (Zillmann, 1972). In this theory, arousal not only

arises from negative emotional experiences, it may also result from positive experiences

that heighten physiological arousal (Geen, 1990).

In his theory, Zillmann (1972) maintains that such heightened arousal levels,

combined with sufficient provocation, serves as an antecedent to aggression (Geen,

1990). In a 1971 study, Zillmann and colleagues enlisted an experimental confederate to

provoke participants, prior to engaging them in either a sedentary task or strenuous

physical activity on an exercise bike. Some time later, participants were allowed to

express their displeasure against the confederate. Those that had been involved in the

strenuous task were found to be more aggressive, in support of this theory (Zillmann,

1972). Therefore, it appears that arousal does not always become attributed to the most


appropriate emotion-provoking event (Geen, 1990; Zillmann, 1972). Although this

finding establishes a link between arousal and aggression, it does not speak of the role of

emotions and their contribution to aggression. As Geen (1990) points out, Zillmann’s

research assumes ‘anger’ is a mediating factor between arousal and aggression.

However, as much of aggression research is measured via self-reported levels of intense

emotions and resultant aggressive behaviours, this assumption is speculative. Perhaps it

should be considered that less negative but equally intense emotions such as excitation

resulting from sensation seeking may also result in heightened physiological arousal.

Temporal considerations, between the arousing event and the anger-provoking

incident are believed critical. If too much time elapses between the two events the

arousal dissipates, making the transfer and identification of the arousal to the provoking

event less likely (Feindler, Marriott, & Iwatta, 1984). The nature and intensity of the

arousal also appears critical to this connection being made. Research using

photographic and videoed forms of erotica as a medium for eliciting arousal has found

evidence to suggest that exposure to videoed erotica resulted in higher levels of arousal

and higher levels of aggression in response to subsequent provocation, than participants

asked to view photographic erotica (Baron & Bell, 1973).

This theory has potentially important implications when considering the use of

on-road activities as ways of dealing with off-road stressors. If a driver is intensely

aroused due to an a significant off-road factor (e.g. an argument) immediately prior to

‘hopping’ in their vehicle, perhaps they are more at risk of engaging in aggressive

driving behaviours. Therefore, the use of the on-road environment as a venue for

dealing with emotional events would be considered a maladaptive way of coping with

life event stress. Additionally, positive arousal due to certain on-road driving

behaviours may be particularly relevant to young drivers. For example, the use of

excessive speed or the presence of peers, may increase physiological and emotional

arousal. In light of this theory, perhaps it is not unreasonable to suggest that high levels

of the personality traits ‘impulsivity’ (Karli, 1991) and ‘sensation-seeking’ (Jonah,

1997) often associated with the aberrant driving behaviours of young road users may

also predispose individuals to higher levels of stimulation or arousal, which serves to

further increase the likelihood of aggression on the roads.


3.3.5 Social Interaction Theory

The social interaction perspective is based on the premise that in social

interactions, when the interests of involved parties diverge, aggression will be adopted in

order to correct the situation (Tedeschi & Felson, 1994). Any aggression instigated by

the ‘actor’ takes the form of coercive behaviours that aim to correct the difference;

however, the use of aggression is viewed as only one potential strategy to achieve that

goal. Contrary to the theories outlined above, however, this perspective is critical of the

view that aggression is compelled from within an individual by feelings of frustration

and/or negative physiological arousal (Tedeschi & Felson, 1994).

Despite this, the developers of the GAM (Anderson & Bushman, 2002) have

incorporated social interaction theory into their model with a view to addressing aspects

of theory that have relevance for aggressive outcomes. Primarily, their interest lies in

the social interaction emphasis upon the decision-making processes, whereby the

decision of how and when to aggress is driven by the evaluation of anticipated costs and

benefits of alternative responses (Tedeschi & Felson, 1994). Anderson and Bushman

(2002) suggest that this theory offers a valuable framework for understanding aggression

that is driven by higher level goals, such as threats to self-esteem (Baumeister, Smart, &

Boden, 1996). This theory also emphasises the perpetrators thoughts of justice and the

process of laying blame, as highly relevant to aggressive outcomes (Tedeschi & Felson,

1994). In this respect it borrows heavily from ‘attribution theory’ reviewed earlier.

In an effort to better understand driving behaviour, aspects of this theory may

help explain on-road aggression. Indeed, it would seem that some drivers use

intimidatory behaviour, which may also be considered aggressive, to influence the

behaviour of other drivers. For example, tailgating could be viewed as intimidatory

behaviour aimed at influencing the travelling speed of the driver in front.

3.4 Interim Summary

Regardless of the perspective taken, most aggression theorists agree that

aggressive behaviour has some fundamental recurring components: a cause, trigger or

antecedent; a resultant emotion; and a behavioural outcome (Bushman & Anderson,

1998; Geen & Donnerstein. 1998; Renfrew, 1997). As outlined above, these key

components are linked through perceptual and cognitive processes. Underpinning the


experience of emotions, cognitive processes influence the intensity of the negative

emotions experienced through conscious or automated evaluation of the situation

(Berkowitz, 1983). The causes/triggers of negative emotion that may influence

aggressive behaviour vary considerably, as does the range of resultant emotions

experienced and the possible behavioural outcomes (Berkowitz, 1983; Geen &

Donnerstein, 1998; Lajunen & Parker, 2001; Shinar, 1998).

Whilst examining the large number of factors known to influence aggressive

driving behaviour, traffic researchers have utilised a number of the foregoing theories to

explain the influence individual situational and person-related factors have on aggressive

road behaviour (Lonero & Clinton, 1998; Lajunen & Parker, 2001; Shinar, 1998; Yagil,

2001). These situational characteristics appear to be context dependent in their ability to

generate aberrant driving behaviour (Lonero & Clinton, 1998; Reason, Manstead,

Stradling, Parker, & Baxter, 1991). At face value, the sheer number of factors that

would need to be considered in this process illustrates the challenges involved in

developing a predictive model of aggressive driving. However, the foregoing review of

human aggression literature repeatedly highlights the importance of cognitive processes

in aggressive driving and indicates these processes clearly warrant further investigation.

3.5 General Aggression Model

In order to base this program of research on a sound theoretical platform, it is

prudent to identify a relevant, comprehensive framework for explaining aggression.

Although Shinar’s Frustration-Aggression theory of aggressive driving is relevant, the

literature review thus far would suggest that emotions other than frustration and anger

may also be relevant to the expression of on-road aggression. A more recent theory of

aggression that offers an amalgamation of a number of human aggression research

theories, encompassing a range of emotions and cognitions that may contribute to

aggressive behavioural outcomes, is the General Aggression Model (Anderson &

Bushman, 2002).

Multiple theories appear to have relevance to aggressive driving. For this reason,

the General Aggression Model (GAM) outlined at Figure 3.1 (Anderson & Bushman,

2002) stands out as a means of synthesising these different perspectives. Not only does

the GAM provide insight into the psychological processes of aggression, it has been


Figure 3.1 The General Aggression Model (Anderson & Bushman, 2002, p. 34)

specifically designed to amalgamate multiple psychological theories of human

aggression so that empirically based interventions may be designed and tested

(Anderson & Bushman, 2002). This model proposed by Anderson and Bushman (2002)

focuses on the individual in a given situation. As illustrated in Figure 3.1, the three main

components of the model are ‘inputs’, ‘cognitive routes’ and ‘outputs’ of a given social

situation. Before discussing the GAM it is necessary to briefly outline the relevant

psychological theories as applied by Anderson and Bushman (2002) and their potential

application to aggressive driving behaviour.

PERSON

SITUATION

Present Internal State:

Affect

Cognition Arousal

Appraisal & Decision Processes

Thoughtful Action

Impulsive Action

Social Encounter

INPUT

ROUTE

OUTCOMES


3.5.1 Schemas and Script Theory

The GAM draws heavily on the use of ‘knowledge structures’ such as scripts and

schemas/nodes mentioned earlier (Berkowitz, 1993; Huesmann, 1988). These

psychological constructs are believed to originate from observation or modelling

consistent with the theories discussed earlier (Bandura, 1977; Berkowitz, 1993;

Huesmann, 1988). They exist within the ‘mind’ and influence an individual’s

perception, interpretation, decision making and action across a variety of social settings.

These structures are believed to influence perception at multiple levels of

information processing and can become automatic through repeated use (Anderson &

Bushman, 2002) i.e. they may be activated without conscious thought or effort. These

structures contain emotions, behaviour and beliefs and can be linked to each other

(Berkowitz, 1993; Huesmann, 1988; Zillmann, 1988). Ultimately, they are used to guide

individual interpretation and behavioural responses within a given situation.

For the purposes of the GAM, Anderson and Bushman (2002) specify that there

are three types of knowledge structures: perceptual schemata, person schemata, and

behavioural scripts. Perceptual schemata are used to identify simple objects (such as a

cat, a car) through to complex events (such as a personal insult). Person schemata

include individual beliefs about other individuals or people (as in stereotypes). Finally,

behavioural scripts contain information about how to behave in a variety of

circumstances (Anderson & Bushman, 2002). Each of these knowledge structures are

linked to affect (emotion) nodes. When a schema linked to an emotion is activated, the

linked emotion is also activated. However, this is tempered with co-existing contextual

information as to when and how a given emotion should be experienced (Anderson &

Bushman, 2002). As indicated in the foregoing literature review, schemas and scripts

influence aggressive behaviours in a variety of contexts (Bandura, 1977; Berkowitz,

1993).

3.5.2 Situation and Person Factors as ‘Inputs’ for the GAM

Similar to the frustration-aggression model of aggressive driving, inputs include

person-related and situational factors that may contribute to aggression (Shinar, 1998).

Person-related factors include all characteristics that a person brings to the situation,

such as personality, sex, beliefs, attitudes, values and scripts/schemas which may contain


multiples of these factors (Bushman & Anderson, 2001). The situational factors that the

authors focus upon are generally aimed at guiding research into the catalysts for human

aggression. These include aggressive cues, provocation, frustration, pain and discomfort

levels, possible incentives and drug/alcohol abuse (Bushman & Anderson, 2001). In

terms of aggressive driving, a considerable number of situational factors have been

found to influence driving behaviour (Lajunen & Parker, 2001; Lonero & Clinton, 1998;

Shinar, 1998; Yagil, 2001) (refer to Section 2.3).

3.5.3 The Process of Aggression According to the GAM

According to the GAM, ‘input’ factors are believed to influence the outcome via

the ‘internal state’. The ‘internal state’ is generated through social cognition, affect and

arousal (Anderson & Bushman, 2002). In this model, the cognitive component refers to

the hostile/aggressive or negative thoughts and associated scripts mentally available to

an individual. ‘Affect’ concerns the current emotional state, or mood, of an individual

that has the potential to prime an individual for aggressive behaviour (Berkowitz, 1993).

In this model, the role of anger in aggression is considered complex, accounting

for the findings of many of the above theories (Anderson & Bushman, 2002). Anger is

believed to reduce inhibitions controlling aggressive responses and provides internal

justification for aggressive retaliations (Anderson & Bushman, 2002). Additionally,

anger is believed to interfere with high level processes, affecting reasoning and

judgement (Anderson & Bushman, 2002). Anger is also believed to allow a person to

maintain aggressive intent over a period of time, increasing attention to the provocative

event and improving their memory of the event (Crick & Dodge, 1994). In an

ambiguous situation, the triggering of anger is also believed to reduce ambiguity,

generally in the direction of hostile interpretations (Anderson, Anderson, Dill, & Deuser,

1998). Thus, anger is believed to prime thoughts, scripts and associated behavioural

responses, guiding an individual’s response to the anger-provoking episode. Finally, it

is believed to intensify behaviour by increasing arousal levels (Zillmann, 1972).

‘Arousal’ refers to the physiological state of an individual. The influence of

arousal is believed to operate in three ways: heightened arousal resulting from an

unrelated source may activate a dominant script response; abnormal arousal levels

sourced from an unrelated source such as exercise can be mislabelled as anger in anger-


provoking situations thus motivating aggressive behaviour (i.e. excitation transfer

theory, Zillman, 1988); and, finally, Anderson & Bushman (2002) suggest that

extremely high or low levels of arousal, if considered aversive states, may stimulate

aggression of their own accord. Extremely low levels of arousal may result due to the

experience of depression, which has been found to impair logical thought processes and

increase irritability (Stanford, Greve, & Dickens, 1995). These three factors that

contribute to the ‘internal state’ are interconnected and may activate each other in a bi-

directional manner, according to script and schema theory (Bandura, 1977; Berkowitz,

1993; Huesmann, 1988).

Figure 3.2 Expanded appraisal and decision-making processes of the GAM (Anderson

& Bushman, 2002)

As discussed above, there is substantial evidence for the existence of this

interactive process resulting in an ‘internal state’ (Berkowitz, 1993, Huesmann, 1988;

Present Internal State

Impulsive Action

Thoughtful Action

Immediate Appraisal

Reappraisal

Resources Sufficient?

Outcome important & unsatisfying?

Appraisal & Decision Processes

Yes No

Yes No


Zillman, 1988). Having developed an internal state, the likelihood of an aggressive

outcome is influenced by an individual’s appraisal process. Figure 3.2 is the expanded

appraisal and decision-making process for the GAM (Anderson & Bushman, 2002).

Therefore, if aggressive driving is not substantially different from basic human

aggression, then such an internal state should also apply to the processing of events that

occur in the on-road environment. At the outset it appears the themes identified by the

GAM provide a useful framework for exploring aggressive driving behaviour.

3.5.4 The Cognitive Appraisal Process in the GAM

Much of the initial, spontaneous appraisal of a situation is believed to be

automatic and subconscious, although filtered through components of the ‘internal state’

(Anderson & Bushman, 2002). In addition, the present ‘internal state’ influences this

immediate appraisal, via inferences made about the behaviour of others guided by

stereotypes and schemas (Crick & Dodge, 1994; Yagil, 2001). If cognitive resources

(i.e. knowledge structures) are sufficient, offering a wider range of possible responses or

views, this may lead to a ‘reappraisal’ of the situation in more constructive ways and

result in ‘thoughtful’, controlled action being taken in a social encounter. However, if

these resources are insufficient and an individual has a narrow, maladaptive range of

scripts available to them, the ‘immediate appraisal’ may result in an ‘impulsive’

response effecting the social encounter (Anderson & Bushman, 2002). In turn, the

behavioural response may be aggressive or non-aggressive depending on the content of

the cognitive appraisal.

3.5.5 Behavioural Outcomes According to the GAM

The developers of the GAM consider that human aggression is “any behaviour

that is carried out with the immediate intent to cause harm” (Anderson & Bushman,

2002, p.28). They also specify that the ‘perpetrator’ must have intended to cause harm

and that the ‘victim’ must be motivated to avoid their aggression (Anderson &

Bushman, 2002). Therefore, in lieu of the historical definition of aggression as either

hostile or instrumental (Berkowitz, 1993; Geen & Donnerstein, 1998), these researchers

focus on ‘ proximate and ultimate’ aggressive behaviours that are intended to cause

harm, as in other models that focus purely on hostile aggressive behaviours (Anderson

& Bushman, 2002). However, considering the nature of aggressive driving and the


potential for relatively minor incidents and on-road reactive behaviours to escalate to

extreme incidents of on-road aggression, their distinction may not prove beneficial in

explaining aggressive driving. This literature review would suggest that until more is

understood about the nature of aggressive driving behaviour, it may be wiser to consider

the full range of behaviours that have been identified as ‘aggressive’ in previous road

research.

As a result of the processes outlined in the GAM a wide variety of behavioural

responses is possible. This range of possible responses is due to the variation that exists

between individuals, especially in terms of variation in personality, their social learning

history and their current internal state at the time of provocation (Anderson & Bushman,

2002). Indeed, while the process is rather

complex, the cognitive appraisal processes involved in driving are perhaps complicated

further through a reduction in effective communication between road users due to the

confines of the vehicle itself. Arguably, the physical parameters of a vehicle may isolate

an individual driver from others, at times distorting one’s perception of the environment

and situational cues.

3.5.6 Applying Relevant Theory to the Phenomenon of Aggressive Driving

In light of the findings outlined in Chapter Two and the aforementioned human

aggression literature, there are several areas of driver aggression that demand greater

attention.

According to the literature reviewed in Chapter Two, it is feasible to assume that

exposure rates to ‘inputs’, or situational characteristics, that trigger aggressive driving

are relatively similar across age groups (VCCAV, 1999; NHTSA, 2002). However,

research indicates that young and other at-risk drivers are more likely to have a more

aggressive behavioural response than other drivers (Lajunen & Parker, 2001).

Consequently, the difference between drivers at risk of aggressive driving and those not

at risk of such behaviours would appear to exist at the intrapersonal level. For instance,

is there a difference in how these driver groups evaluate anger-provoking situations or

deal with their on-road emotion?

Referring back to the GAM perhaps differences do exist in the ‘appraisal and

decision-making’ processes outlined. Aggressive drivers, in particular, may have


difficulty in the immediate appraisal of on-road situations and perhaps the cognitive and

coping ‘resources’ available to them are less functional than those available to older,

more experienced drivers.

Also, psychological theories included within the GAM would suggest that

deficits in coping resources/strategies can include an increased availability of

hostile/aggressive schemata or scripts (Farrington, 2000; Vaughan & Hogg, 1995); a

reduced availability of overriding inhibitions which can alter behaviour (Standford &

Barratt, 1995; Vigil-Colet & Colorniu-Raga, 2004); and/or a reduced number or quality

of available constructive coping strategies or scripts in the face of provocation

(Berkowitz, 1998; Bushman & Anderson, 1998; Crick & Dodge, 1994). Hence, if a

young driver had insufficient ‘resources’ in the form of cognitions, then perhaps

aggressive driving behaviour would be more likely. This suggestion would also be

consistent with the review of risk factors for aggression, where it appears that exposure

to one or more of the factors may lead to the adoption of dysfunction/maladaptive

coping behaviours such as aggression (Chang et al., 2003; Cummings et al., 2004;

Loeber, Farrington, Stouthamer-Loeber, Moffit, Caspi, & Lynam, 2001). Alternatively,

it may result in greater negative emotionality which may increase the risk of reactive

aggression in the face of perceived provocation (Cooper, et al., 1995).

Life-stress has also been found to influence the experience of on-road aggression

(Arnett, Offer, & Fine, 1997; Novaco, Stokols, & Milanesi, 1990). Therefore, perhaps

there are differences between drivers at-risk of aggressive driving and other road users in

the levels of state stress brought to the on-road environment. Aggressive drivers may

experience greater transfer of stress from the off-road environment to the on-road

environment. Aside from having immediate impacts upon stress levels, exposure to

aggression risk factors may also enhance an individual’s long-term susceptibility to

stress (Verona, Patrick, & Lang, 2002). Therefore, it would be helpful to look at driver

coping styles and strategies. This approach could broaden our understanding of

constructive and maladaptive ways of behaving on the road.

Findings relating to ‘sensation seeking’, ‘impulsivity’ and psychological

disorders, outlined above and in Chapter Two (Bor, 2004; Fossati et al., 2004; Iacano et

al., 1999; Karli, 1991; Lajunen & Parker, 2001; Loeber et al., 2001; Zuckerman & Neeb,


1980) also provide evidence of additional trait factors that may distinguish aggressive

drivers from the general driving population. Therefore, they also warrant further

investigation in an Australian sample.

Interestingly, the review of the risk factors for aggression implies that although

aggressive tendencies are developed or acquired during childhood and adolescence, they

have the potential to persist across time (Farrington, 2000, 2004; Huesmann et al., 2002;

Murphy et al., 2004). Therefore, it is somewhat surprising there is less evidence of

aggressive driving by older drivers. Alternatively, are they more prevalent in more

extreme acts of on-road aggression? These questions will be explored in greater depth

throughout this body of research.

3.6 Additional Research Questions

The following review of theoretical issues has identified two further research

questions relating to aggressive driving that warrant further investigation. These

questions and a brief rationale for each are detailed below.

RQ5 What are the cognitive and emotional processes characterising aggressive

driving behaviour?

This review highlights the relevance of psychological processes and theory in the

likelihood of on-road aggression. In the main, literature to date has focussed on the

feelings associated with aggressive driving (Deffenbacher et al., 2002; Lajunen &

Parker, 2001; Shinar, 1998) specifically examining frustration and anger. However, this

literature review has established that perhaps other emotions, such as excitement, have

the potential to contribute to aggressive driving, especially for younger drivers.

To a much lesser degree, researchers have looked at the cognitive processes

associated with the behaviour, such as negative attributions (Yagil, 2001). However, no

research has yet attempted to examine the range of cognitions or decision-making

processes associated with aggressive driving. As CBT based interventions are beginning

to emerge for aggressive drivers, it would be prudent to expand research into the

cognitive and emotional contributors to on-road aggression.


RQ6 Are there differences in the characteristics of those drivers who are prepared to

engage in hostile acts of aggressive driving compared to those who only report

engaging in instrumental acts of aggressive driving?

This research question represents an extension of RQ2, outlined in Section 2.9. RQ2

related to the need to investigate whether some drivers are more likely to engage in

aggressive driving and, if so, what their psychosocial characteristics are. However, the

foregoing discussion of risk factors for the development of aggressive tendencies

highlighted specific person-related factors that may predispose an individual to violence

or anti-social behaviours. It is also noted that the exposure to such factors has the

potential to manifest aggressive or anti-social behaviour beyond the ‘developmental

years’. Consequently, is exposure to one or more risk factors for aggression more

prevalent in drivers that engage in more extreme on-road aggression, thus distinguishing

them from general road users or those prepared to engage in ‘instrumental aggression’

only? Hence, RQ6 focuses on the characteristics of the subset of aggressive drivers who

are prepared to engage in more hostile acts, in order to determine whether they differ

from other aggressive drivers.

3.7 Chapter Summary

This chapter first reviewed psychological theories that have been previously used

to explain human aggression from differing perspectives, some of which have also been

empirically tested within the context of aggressive driving. It also looked at those

theories that have the potential to explain facets of aggressive driving not previously

considered. A review of general risk factors for aggression highlighted the relevance of

such factors in the conduct of aggressive driving research.

Finally, the GAM, as a synthesis of the above theories, was outlined and

discussed. For the purpose of this thesis, the GAM was proposed as a framework for

exploring aggressive driving within this program of research.


Chapter Four: A Qualitative Study of Young Drivers as a High-risk Group

4.1 Introduction........................................................................................................... 105 4.2 Method ................................................................................................................ 106 4.2.1 Participants ............................................................................................. 106 4.2.2 Procedure ................................................................................................ 106 4.2.3 Materials ................................................................................................. 106 4.2.4 Analysis .................................................................................................. 108 4.3 Results and Exploration of the Qualitative Data .................................................. 108 4.3.1 Socio-Demographics and Driving Exposure .......................................... 108 4.3.2 What is Considered Aggressive Driving? .............................................. 109 4.3.3 Perceived Causes of Aggressive Driving ............................................... 109 4.3.4 Situational factors ................................................................................... 110 4.3.4.1 Behaviours ................................................................................ 110 4.3.4.2 Facilitating Factors ................................................................... 112 4.3.4.2.1 Type of Vehicle ..................................................... 113 4.3.4.2.2 Type of Road ......................................................... 114 4.3.4.2.3 Vehicles On-Road and Pace of Living .................. 116 4.3.4.2.4 Time Pressure ........................................................ 117 4.3.4.2.5 Passenger Effect .................................................... 118 4.3.4.2.6 Temperature ........................................................... 119 4.3.4.2.7 Music ..................................................................... 119 4.3.5 Person-Related Factors ........................................................................... 119 4.3.5.1 State Factors ............................................................................. 119 4.3.5.1.1 Mood ..................................................................... 119 4.3.5.1.2 Life-Stress ............................................................. 120 4.3.5.1.3 Job Stress ............................................................... 121 4.3.5.1.4 Driving Stress ........................................................ 122 4.3.5.2 Trait Factors ............................................................................. 122 4.3.5.2.1 Age and Gender ..................................................... 122 4.3.5.2.2 Personality ............................................................. 123 4.3.5.2.3 Prior Learning ........................................................ 124 4.3.5.2.4 General Attitudes About Other Drivers ................. 125 4.3.5.3 General Transfer of Emotion to the On-Road Environment .... 125


4.3.5.4 Transfer of On-Road Generated Stress to the Off-road Environment ............................................................................. 127 4.3.6 Personal Experiences with Aggressive Driving ..................................... 128 4.3.6.1 Victims or Perpetrators ............................................................. 129 4.3.6.2 Type of Road ............................................................................ 129 4.3.6.3 On-road Behavioural Causes .................................................... 130 4.3.6.4 Pre-event Emotional State ........................................................ 132 4.3.6.5 Range of Emotions Experienced .............................................. 133 4.3.6.6 Cognitions During the Incident ................................................ 134 4.3.6.7 Behavioural Responses to On-Road Provocation..................... 136 4.3.6.8 Post-Event State........................................................................ 138 4.3.6.9 Personal Accounts of Off-Road Stress Brought to the On-Road Environment.............................................................. 139 4.4 Discussion ............................................................................................................. 141 4.4.1 Situational Factors .................................................................................. 141 4.4.2 State and Trait, Person-Related Causes .................................................. 142 4.4.3 Range of Emotions During an On-Road Incident .................................. 143 4.4.4 Cognitions During an On-Road Incident ................................................ 144 4.4.5 Behavioural Responses to On-Road Provocation ................................... 145 4.4.6 ‘Post Event State’ or Transfer to the Off-Road Environment ................ 146 4.4.7 Transfer of Emotions to the On-Road Environment .............................. 146 4.4.8 Coping Strategies Adopted by Young Drivers ....................................... 147 4.4.9 Addressing the Research Questions ....................................................... 148 4.4.10 Strengths and Limitations of the Study .................................................. 150 4.4.11 Implications of Findings for the Development of a Psychosocial Framework for Aggressive Driving ........................................................ 151 4.4.12 Chapter Summary ................................................................................... 154


4.1 Introduction

This study was designed to act as an exploration of aggressive driving from the

perspective of one of the key potentially at-risk groups for aggressive driving, young

drivers, as they are frequently over-represented in the findings of aggressive driving

research (Harding et al., 1998; Lajunen & Parker, 2001; Lawton & Nutter, 2002; Shinar,

1998; VCCAV, 1999). In order to provide greater insight to the phenomenon, it was

considered pertinent to examine young driver perceptions of what behaviours constitute

aggressive driving and their recalled experiences of such driving behaviour.

Whilst investigating factors that contribute to aggressive driving behaviour, this

phase was also designed to explore the relevance of human aggression theory from

within the framework of the GAM (Anderson & Bushman, 2002). The literature review

indicates that the GAM may assist in explaining aggressive driving behaviour arising

from the multiple person-related and situational sources, discussed in Chapters Two and

Three.

This study utilised a qualitative approach to facilitate a broad-based approach to

the phenomenon, providing ‘information-rich’ data from the perspective of Australian

drivers. In addition, a qualitative exploration may assist in explaining the possible

transfer of negative emotion to the road environment, as well as the possibility of

transfer to the off-road environment (i.e. home or work).

This study examined aspects of five research questions identified in Chapters Two

and Three:


driving?

RQ2 Are some drivers more likely to engage in aggressive driving and, if so, what

are their characteristics?


behaviours?


RQ5 What are the cognitive and emotional processes which characterise aggressive

driving behaviour?


Being qualitative in nature, this study was not driven by specific hypotheses but

rather adopted a thematic approach to the research questions.

4.2 Method

4.2.1 Participants

To provide a cross-section of the young driver population, participants were

recruited from a variety of sources including the Queensland University of Technology

(QUT), the Queensland College of Technical and Further Education (TAFE) and via an

external agency (Northern Field Services [NFS]). QUT participants were granted credit

towards the completion of their first year Psychology program. Those participants

recruited through TAFE and NFS were paid $40.00 each for their involvement. A total

of 47 participants were recruited, comprising 23 males and 24 females. The selection

criteria required that participants were 17 to 25 years of age (M = 20.6 years) and were

the holder of a current driver’s licence.

4.2.2 Procedure

Six focus groups were conducted, each taking approximately 1.5 hours to

facilitate. Two focus groups were recruited from each participant pool. In an effort to

counteract any gender bias, equal numbers of males and females were allocated to each

group. Prior to commencing each discussion participants were made aware of the nature

of the study, assured of anonymity, and asked to read and sign an information/consent

package (see Appendix A). At the conclusion of the TAFE and NFS focus groups,

participants were financially recompensed for their time and travelling costs. All

participants were asked to complete a brief socio-demographic questionnaire prior to

commencement of the focus group (see Appendix B). Approval to conduct this study

was obtained from QUT’s Human Research Ethics Committee.

4.2.3 Materials

Bearing in mind that this study was an exploration of the applicability of the

GAM and the underlying constructs considered relevant to aggression (Anderson &

Bushman, 2002), the focus group protocols (see Appendix C) were tailored to explore

the relevant components of the GAM in the context of aggressive driving behaviour and

the transference of negative emotion to and from the road environment. Figure 4.1 is a

map of the main concepts explored during the study, which were informed by the


constructs within GAM theory (Anderson & Bushman, 2002) and earlier aggressive

driving research (Shinar,1998). They also provided the structure for the focus group

protocols.

Within this study, a two-fold approach was adopted to explore the research

questions. The first approach was macro in nature, examining general perceptions of

what factors were believed to contribute to aggressive driving. The second approach

involved exploring these questions from within personal, recalled encounters with

aggressive driving. The focus group questions were open-ended and participants were

actively encouraged to contribute:

• their perceptions of what constitutes, and causes, aggressive driving behaviour

in general;

• any personal experiences they have had with aggressive driving (either as the

victim or the perpetrator) and the effect this had on any subsequent behaviour;

• any emotions and cognitions they recall having experienced before, during and

after the event; and

• any off-road experiences that may have resulted in them driving whilst feeling

upset, tense or angry.

Demographics Direct/Indirect Causes

Pre-event Emotional State

Types of Cognitions

Range of Emotions Experienced

Behavioural Responses

Post-Event Emotional State

Post-Event Behaviour

Figure 4.1 Map of concepts explored in accordance with the GAM (Anderson & Bushman, 2002).


4.2.4 Analysis

Using qualitative reduction techniques, focus group transcripts were analysed

and sorted into themes and ideas associated with the phenomenon (Moustakas, 1994).

This method involved recording and transcribing individual recollections of experiences

with aggressive driving including the roles of the victim and the perpetrator.

Commonalities in situational causes, emotions and thoughts experienced were identified,

reducing the phenomenon of aggressive driving as it is experienced by young drivers,

into repeated themes and concepts consistent with GAM factors. The qualitative

software package NVIVO was used to analyse participant responses to the protocol

questions.

4.3 Results and Exploration of the Qualitative Data

Before reporting the main results of this research, it is first useful to provide

details of the participants’ socio-demographic characteristics and driving exposure.

Following this, the wide range of situational and person-related factors that were

identified by participants as the main causes of aggressive driving will be reported and

discussed.

Finally, the results pertaining to the individual experiences with aggressive

driving will be reported. Note that participant quotes have been coded to assure

anonymity e.g. FG3. The code is based on the gender and first initial of the participant

followed by their focus group number. Where two participants in the same focus group

had the same initial a ‘1’ or ‘2’ was inserted before the focus group number.

4.3.1 Socio-Demographics and Driving Exposure

The socio-demographic and driving exposure data was analysed using SPSS (see

Appendix D). Almost half of the participants (n = 23) reported having held a licence for

less than two years. Further, 62% reported driving their vehicle 15 times or less per

week. Additionally, 64% reported driving 15,000km or less per year, a finding that may

be considered consistent with reports by 66% of participants that they drove mainly on

city roads, with some highway or country driving. Forty-five per cent of participants

reported that they drove for work purposes.

Approximately 75% of participants indicated that they believed that aggressive

driving behaviour is on the increase on Queensland roads. The remaining 25% were


‘unsure’ about the trend.

4.3.2 What is Considered Aggressive Driving?

Although the participant responses readily recalled on-road incidents that they

referred to as aggressive driving, there appeared to be no consensus regarding a

definition of aggressive driving. The results would suggest that the term ‘aggressive

driving’ means different things to different people. However, a number of common

themes emerged in the discussion, which appeared consistent with the provisional

definition of aggressive driving outlined in Section 2.2.5.3. These common themes

were: the ‘dangerousness’ of aggressive driving incidents, the intense emotion

associated with the incidents, and the element of intent underpinning the behaviour of

aggressive drivers. In response to initial questions concerning the causes of aggressive

driving some participants (n=10) spoke of ‘danger’ as a defining element of aggressive

driving behaviour. Also, many of the behaviours identified in this study may be

considered aggressive when an element of ‘danger’ is involved.

In this sample of young drivers, there was also evidence of the perception that an individual may drive aggressively without danger:

“ Guys will typically not be dangerous but just drive aggressively…” (FJ4)

Further, it was suggested by five participants that dangerous driving behaviours

are permissible if they only pose a danger to themselves.

“ To me it doesn’t have to be dangerous. I see a chicane and I go, ‘I can get

through that’. Half the time what you are doing is just stupid…and the only

thing that slows you down a bit is a few speed bumps and you push it. That’s

aggressive driving, but it’s only dangerous to myself.” (FT14)

Arguably, such a view fails to account for the impact or possible consequences

of this behaviour upon themselves and other road users or pedestrians. It would also

appear that as long as there are no obvious, immediate negative consequences for this

behaviour then the behaviour is not considered a danger to other road users.

4.3.3 Perceived Causes of Aggressive Driving

In order to explore RQ1, participants were first asked two open-ended questions

that aimed to explore the perceived causes of aggressive driving behaviour:


• ‘What do you think are the main causes of aggressive driving?’; and

• ‘What things make you particularly angry on the roads?’

In response to the protocol questions outlined above (Section 4.3.2), participants

reported a large number of causes of aggressive driving behaviour. Most of these factors

lent themselves to being categorised in accordance with the GAM (Anderson &

Bushman, 2002) as either person-related or on-road situational factors.

Consistent with previous research and for the purposes of understanding the

person-related factors associated with aggressive driving behaviour, it was considered

appropriate to further divide this category into state and trait factors. State person-

related factors reflect those that are transient and subject to situational characteristics,

and trait person-related factors those that are mainly static and/or more enduring.

The situational factors identified by participants also appeared to consist of two

main themes: ‘direct causes’ (i.e. the behaviour of ‘other drivers’) and other ‘indirect

causes’ (i.e. those listed as facilitating factors) (see Figure 4.2). ‘Direct causes’ are

specific behaviours that result in the interpretation of a driver’s behaviour as dangerous

or careless, giving rise to feelings of threat, frustration and/or anger. Conversely,

‘indirect causes’ include a wide range of on-road situational factors that may not

necessarily lead to aggressive driving behaviour in their own right. These factors appear

to add to the likelihood of on-road behaviour being interpreted as aggressive.

At times throughout this study, the term ‘direct/indirect causes’ has been adopted

to refer to the two broad types of situational factors identified in the study. Figure 4.2 is

a diagrammatic presentation of the direct and indirect causes of aggressive driving cited

by participants according to the major themes identified. The number beside each factor

represents the number of citations across the six focus groups.

4.3.4 Situational Factors

4.3.4.1 Behaviours

The wide range of contributing factors outlined in Figure 4.2 do not appear to

differ markedly from those identified in previous research about factors that contribute

to aggressive driving behaviour (Lonero & Clinton, 1998; Lajunen, Parker, & Stradling,

1998; Shinar, 1998). Participants cited 26 situational factors that they consider may

contribute to aggressive driving behaviour.


Trait Person-Related Factors

- age (16) - gender (4) - personality (8) - inexperience (9) - prior learning (7) - stereotypes (16) - attitudes (10)

State Person-Related Factors

- mood (12) - lifestress(10) - driving stress(4) - job stress(9)

Situational Factors

Errors & Violations - failure to stop/give way (8) - highbeam flashing (6) - cutting in/off (37) - tailgating (26) - mis-use/lack of indicators (14) - overtaking (3) - speeding (27) - dragging-off (3) - not allowing merge (17) - slow driving (15) - slowing to view accidents (2) - delaying at lights (5)

Type of road - city/suburban/carparks (17) - roadworks and delays (12) - congestion (13)

Type of vehicle

- vehicle appearance (17)

- cyclists (1) - mechanics (8) - sense of security(4) - size of car (5)

Facilitating Factors

Miscellaneous

- driving with peers (10)

- timepressed (24) - temperature (2) - pace of living (3) - greater number of

vehicles (4) - music (3)

Behaviours

Person-Related Factors

Figure 4.2 Participant responses to the causes of aggressive driving behaviour by major themes identified


Importantly, it appears that a critical issue in aggressive driving is the need for

driver behaviour to be perceived as aggressive by other road users.

Of the specific behaviours cited as causing aggressive driving, it was noted that

some of the behaviours listed may not necessarily be deemed aggressive when

considered in isolation and out of context, e.g. slow driving, misuse of indicators or

speeding. Hence, the decision was made to title these contributing behaviours as ‘errors’

in judgement, and/or ‘violations’. For example, a driver exceeding the speed limit on a

highway by 10km/h, may not necessarily be considered aggressive. However, should

that driver then intentionally change lanes frequently without indicating, their behaviour

may be considered aggressive by others.

“Speeding itself doesn’t annoy me, if they are just going past…” (FT3)

“…but it does annoy me when they start to cut in and out…” (FG3)

Alternatively, the act of ‘slow driving’ is not necessarily aggressive if not

intentional or possibly explained by other factors such as the age of the driver. For

example, elderly drivers that drive slowly are generally not considered aggressive, but

rather more frustrating or annoying:

“…Older slow drivers when you are at a green light and it takes them about five

seconds to realise (the light has changed). Ooh, that annoys me, oh I hate

that…” (MR3)

Therefore, there appear to be complex processes that influence the perception of

‘other driver’ behaviour as aggressive. As such, the on-road situational factors cited by

participants were, in the main, furnished in situational context when asked to reflect

upon their personal experiences with on-road aggression. This is consistent with

previous research that emphasises the influence of context upon on-road situational

factors that contribute to aggressive driving behaviour (Lajunen & Parker, 2001; Shinar,

1998).

4.3.4.2 Facilitating Factors

In response to the questions identified in Section 4.3.2, a series of facilitating

factors that appear to influence the likelihood of aggressive driving were also identified.


Through previous research many of these factors have been found to provide the

situational background for aggressive driving behaviour (Section 2.2 and 2.3).

4.3.4.2.1 Type of Vehicle.

A number of participants (n = 35, 74%) spoke about vehicle characteristics they

believe contribute to aggressive driving behaviour. General reference was made to the

size of vehicles typically involved in this behaviour. Their comments spoke of how the

size of a vehicle may enhance or detract from a driver’s personal sense of security as

well as influence the likelihood of involvement in aberrant driving behaviours.

Other participants also referred to instances of young drivers mechanically

modifying their vehicles to enhance speed and performance. In such cases, the activity

of mechanically enhancing vehicles appears to serve as a social interaction or hobby for

the young drivers involved.

Participant observations concerning vehicle appearance, the size of the vehicle

and enhanced mechanics were made with reference to young, male drivers only. A

number of participants made reference to the specific characteristics of vehicles and how

they may facilitate aggressive driving behaviours (see Table 4.1).

Table 4.1 References made to vehicle characteristics

Vehicle Characteristics

Quotes n

Size of Vehicle “I drive a little car too and I think there are stereotypes about people that drive certain cars and how you treat them…”(FN2)

“…I think the type of car you drive will help you feel safe and maybe make it easier to respond aggressively to another driver…” (MD1)

“I just think that it is because they are larger and they take advantage of the size of the vehicle…” (MJ22)

8

Make of Vehicle “…if it is a Holden and I drive a Ford I really want to overtake them and I’ll speed up and change lanes to do it.” (MJ12)

3

Modified Vehicles “My brother and his mates they just love cars. They are always doing something to them and working on them to hot them up. I hate driving with them they drive really recklessly…What they do to their cars to make them go faster and stuff is ridiculous.” (MP2)

“...there is this group called ‘downshift’ that drive modified cars & every Sunday afternoon they’d meet & drive down the Gold Coast & late at night when it’s not too busy…they line up four cars across (the road) & have these massive races on the highway.”(MA2)

7


Several references were also made to the specific make or type of vehicle

influencing driver involvement in aggressive behaviours: four wheel drives, larger

vehicles such as trucks and buses, and taxis. These results are represented under

‘vehicle appearance’ in Figure 4.2. The quotes in Table 4.2 typify participant

comments. These findings are also noted to be suggestive of a lack of respect for other

road users.

Table 4.2 Types of vehicles identified as being more likely to be involved in aggressive

driving Type of Vehicle

Quotes n

Four Wheel Drive

“…it is people with things to prove, like ‘four-wheel drives’ love driving up your (expletive) and just giving it to you. Proving they are bigger than you are …”(MP2)

6

Trucks and Buses

“ …especially trucks. If you are in front of them, by law they are to let you in, but they just think I am 20 times bigger than you. I’ll just go straight over the top of you.” (MR3)

6

Taxis “ …a lot of people, like cabbies, have no respect for you on the road or for the road rules” (FM5)

5

4.3.4.2.2 Type of Road.

Nine focus group participants cited congestion as either a cause of aggressive

driving or as generating feelings of anger that may contribute to aggressive driving.

Table 4.3 presents the findings concerning the characteristics of the road environment

associated with aggressive driving.

As reflected in the examples given in Table 4.3, congestion appears to be more

common during peak hour periods and in built-up areas. City driving, in general, was

reported as a contributing factor to aggressive driving by seven participants. As

congestion and a greater number of road users are more commonplace in the cities, it

may be that aggressive driving behaviours may be also.

Among these seven responses, some five participants further qualified their

responses explaining that repeated exposure to city driving seems to increase a driver’s

tolerance for aberrant driving behaviour (see Table 4.3).


Table 4.3 Type of road characteristics identified as typically associated with

aggressive driving Road

Characteristics Quotes n

Congested “…traffic is really bad on Friday afternoon…as much as you are excited

about the weekend, you wonder ‘why do I have to deal with a traffic jam’ to get to that weekend.” (FK4) “I was so pissed off from driving so far, and the traffic I had to contend with, and the people I had to contend with.” (FC3)

9

City Roads

“I hate driving in town and I go maybe once every three months. When I am in town people cut me off and I get real fired up and drivers just make me ropable.” (MS5) “…when I first started driving it was just around home and I guess little things people did would get to me, but now I do more city driving and I guess you have to be an aggressive driver to drive in the city…I guess that you get used to it…and if you need to get where you need to be I think you have to be an aggressive driver…you just get used to bad behaviour continuously.” (FK4)

7

Repeated Exposure “…I used to (have a response) when I first started to (drive in the city), but now it’s frustrating. What really frustrates me actually is when you get stuck in traffic and then there is somebody else behaving badly and all you think is ‘will this ever end?’ … ‘wow, I have got to change jobs…’.” (FJ4) “But everyone tailgates, it’s pretty normal in the city.” (FA1)

5

Roadworks/Delays “It (frustration) goes up. Because when they were in H… Street, and they are doing the whole road there, it took me a good hour to get up there and back down and people will not let you in. It drives me mad… it’s frustrating.” (FK5)

11

Another road condition that may give rise to feelings of frustration and/or anger

is delays caused by roadworks (refer to Table 4.3). A number of participants spoke of

their frustration and/or anger when confronted with roadworks and subsequent delays.

Four of these participants, however, also specified that had they known in advance about

the delays, they would not have felt as annoyed or frustrated. Perhaps this highlights

that it may be the unexpected nature of delays that contribute to feelings of anger and

frustration. Some participants also suggested they would have taken alternative routes to

avoid the delays if possible.


“With roadworks, I find it annoying if it’s unexpected, but if I know roadworks

are there I would be more tolerant and patient.” (MA5)

“I knew there was going to be traffic. When they were doing the roadwork at

Bald Hills, I would quite often go through Albany Creek to get there…but half

the time I would forget and then I would be held up by roadwork, then be fuming

at myself more than anything.” (MA6)

Finally, participant responses also revealed that certain driving behaviours such

as speeding and tailgating may be considered particularly anger-provoking on specific

types of roads e.g. suburban roads (n = 2).

“Speeding. It’s the biggest one, it makes me angry, definitely. If I see it in the

suburbs, it makes me really angry.”(FS1)

“…I think it depends on the kinds of road…if it’s a country road you, you

(normally) let them pass you if you are out for a drive, by just slowing down a

bit. You wonder why so many people don’t just overtake you if they are that way

(in a hurry) and they sit so close to you and they are aggro.” (MA6)

4.3.4.2.3 Vehicles On-Road and Pace of Living.

Earlier reference to congestion on certain types of roads is also consistent with

the participants’ general references to the increasing number of vehicles on the road.

Table 4.4 presents statements relevant to these findings.

The perception of an increased number of vehicles on the road was considered a

contributing factor to aggressive driving. Participant responses suggest that the

increased number of vehicles using the roads added to feelings of urgency, pressure or

frustration. Expanding on this concept, three participants referred to a sense that the

general pace of living had increased, manifesting in a common perception that people

are always in a hurry.


Table 4.4 Perceived increase in number of vehicles on the road and increased pace of

living

Characteristics

Quotes n

(15%)

Increase in Vehicles on Road

“Maybe its just that there are more cars on the roads and having to go over the same amount of roadway.” (FS1) “… too many people using the road, too many people driving, so you get frustrated …” (MA2)

4 Increased Pace of Living

“I think that people are just really in a hurry these days and the roads are busy and you drive like you are reacting to pressure, like you need to get somewhere in a hurry.” (FT3) “They are frustrated, hurried, pressured and in some people it comes out in the way they drive.” (MD1)

3

4.3.4.2.4 Time Pressure.

A similar theme was reflected in response to the question, ‘What do you think

are the main causes of aggressive driving?’ A number of participants spoke of ‘time

pressure’ (n = 16, 35%). Table 4.5 outlines participant findings and relevant themes

identified as ‘time pressure’.

Table 4.5 Role of time pressure

Effect

Quotes

n

General “I think it is one of the main causes of aggressive driving…whether or not they are late. I think that contributes to aggressive driving on the road.” (MD3) (Quote 1)

16 Behaviour Influence

“…time constraints. As well, people tend to be rushing so they drive aggressively

or extremely, changing lanes etc...” (MJ3) (Quote 2)

8 Perception of Goal Blocking

“I was running late the other morning …and that really annoys me that they don’t

travel the speed limit that they are supposed to.” (FN4) (Quote 3) “Especially, when you are in a rush to get somewhere and someone is holding

you up. You drive as quickly (as you can), and take every opportunity and space to move quicker.”(FK3) (Quote 4) “Like if I am running late for work and there has been someone that is pissing me

off by going really slow…” (MP6) (Quote 5) “..If I’m doing the speed limit or even a little bit above and I’ve got someone right

behind me...right on my tail, I get really annoyed and I put my brakes on & slow down & let them know (about the annoyance) in that way…” (FG3) (Quote 6)

5


‘Time pressure’, frequently mentioned as ‘running late’, was expressed as a

causal contributor to aggressive driving (refer to Table 4.5, Quote 1). Under time

pressure, participants indicated that a driver may increase their travelling speed and/or

frequently change lanes (n = 8) (Quote 2). Participants also made reference to the

contribution of time pressure to an increased likelihood of perceiving ‘other driver’

behaviour as ‘goal blocking’ i.e. causing delays to their journey (Quotes 3 and 4). It was

also noted in participant responses that time pressure commonly elicits feelings of

agitation or frustration (Quote 5). Additionally, when a driver feels pressed for time and

is then faced with a perceived provocation or ‘goal blocking’ behaviour, participant

responses suggest these feelings are amplified and may result in the increased likelihood

of an aggressive behavioural response (Quote 6).

4.3.4.2.5 Passenger Effect.

The mood state of young drivers also appears to be readily influenced by the

presence of passengers (refer to Table 4.6). A number of participants (n = 10) spoke of

the social influence of peer passengers upon driving behaviour (Table 4.6). These

results suggested that the presence of peers may have a negative impact upon driving

behaviour, particularly for young males. Alternatively, two participants spoke of a

positive influence upon their driving behaviour when the passenger was older.

Table 4.6 The influence of passengers upon driving behaviour

Effect

Quotes

n

Peers

“…a lot to do with peer groups…in front of their (male drivers) friends they just have to prove that they can go faster and try to do burn outs… …as soon as they have their friends in the car it’s like they have to impress them and they go nuts and drive way too fast and try to overtake and beat everyone.”(FK2) “It’s also like your friends and peers as well. I guess it’s like you can’t actually let them see that your car is gutless, or that you are a woosy driver.”(MA2) “You might just drive faster if you’ve got your mates in the car, and you are stuffin’ around and yelling out the window and stuff.” (MP6)

10

Others “…Dad was in the car so I wouldn’t dare speed. It made me a bit nervous really. I wanted to overtake the truck, but I felt him looking at me …he just wouldn’t approve.” (MA5)

2


4.3.4.2.6 Temperature.

Another factor cited by two participants as a contributing factor to aggressive

driving behaviour was temperature.

“…you get angry because you are hot and sweaty and feeling

uncomfortable so you just want to get out of there.” (FC22)

4.3.4.2.7 Music.

A few participants (n = 3) mentioned loud or up-beat music as possibly making a

contribution to the likelihood of aggressive driving behaviours (refer to Table 4.7). It

was observed that listening to such music may affect the speed at which a driver is

travelling, potentially through excitatory effects. Conversely four participants spoke of

the possible influence of music as a form of relaxation in traffic.

Table 4.7 Influence of music upon driving behaviour

Effect

Quotes

n

Excitation

“….maybe the music you listen to. If you listen to fast music sometimes it makes me go a bit faster.” (MB26)

3

Calming “….if I am running late for work, I put some tunes on.” (MR4) “….your favourite song or something funny comes on then you forget about it again.” (FT14)

4

4.3.5 Person-Related Factors

4.3.5.1 State Factors

4.3.5.1.1 Mood.

A number of participants (n = 12) spoke in general terms of the mood that drivers

bring to the on-road environment. Nine references were made to the way in which mood

influences on-road driving behaviour with the possibility of increasing the likelihood of

aggressive driving. Specifically, participants spoke of mood contributing to speeding (n

= 7) and aberrant driving behaviour (n = 2). Table 4.8 outlines the cited effects of

‘mood’ on driving behaviour and their frequency within the sample.

Reference was also made to poor mood having the potential to increase the

likelihood of perceiving ‘other driver’ behaviour as anger-provoking or aggressive.


Further, it was suggested that one’s mood may influence the way in which one responds

to various on-road situations.

Table 4.8 Participant responses relating to influence of mood upon driving behaviour

Resultant Effect

Quotes

n

Speeding “…if I have had a problem at home and I’m driving, I just try to go as fast as I can to get from one place to another, and if I am in a rough kind of mood I try to catch as many lights as possible as quickly as possible.”(MA5)

7 Aberrant Driving

“It’s also…the mood you are in. Sometimes if you are angry you will just do whatever it takes to get to your destination.” (MB6)

2 Perception of Aggression

“…like if you are trying to catch the train or something and you’re late…you think everybody’s trying to hold you up and you get really annoyed…only because you are coming from …the mood you are in.” (FK2)

“…a lot to do with mood…some things wouldn’t bother you on another day, but someone failing to indicate on this sort of day may result in aggression because you’re in a bad mood… …mood has a lot to do with how you deal with situations that come up on the road.” (FC1)

2

4.3.5.1.2 Life-Stress.

Whereas current mood may be a more transient state of being, life stress is

generally more persistent, although not normally permanent. A number of focus group

participants (n = 11) spoke of life-stress as a contributing factor/cause of aggressive

driving. Table 4.9 outlines the comments associated with the influence of life-stress and

its potential impact on aggressive driving behaviours.

A number of participant (n = 9) references to life-stress and its impact on driving

behaviour were of a general nature (see Table 4.9). Many of these suggested that life-

stress tends to make drivers less patient, increasing their preparedness for aggression on

the road.


Table 4.9 Life-stress and potential impacts upon aggressive driving

Resultant Effect

Quotes

n

General “People that are constantly tense in their lives, constantly stressed. That would effect their driving.”(FJ5) “…frustration and anger coming out in all parts of people’s lives and the road is just another way of showing it.” (MD1)

“Most of it (aggressive driving) results from stress of life and impatience.” (MR3) “I think people are stressed. Add a bad day they will be more agro on the road…and more frustrated. People that are frustrated drive erratically as well…” (FM5

11

4.3.5.1.3 Job Stress.

A number of participants (n = 9) referred to work related stress and its perceived

impact upon the likelihood of aggressive driving behaviours (see Table 4.10).

According to participants, job related stress brought to the on-road environment is likely

to increase internalised feelings of frustration/anger with the behaviour of ‘other

drivers’, increasing one’s preparedness for on-road aggression. Two participants

suggested that recurrent thoughts, or rumination, about the stressful event/episode

reduced the amount of attention paid to the on-road environment.

Table 4.10 Participant responses relating to job stress

Resultant Effect

Quotes

n

General “If you have had a really bad day at work or something has just happened and it really (expletive) you off, you tend to arc up really quickly with people…” (MB26) “ You’re tired, then going to work, then getting (expletive) off from work, and then getting cut off …”(MA6)

9

The foregoing results suggest that under the affects of job stress, driver

behaviour may be negatively influenced. Perhaps this is due to ruminating about the

source of stress, which reduces attention to the on-road environment. Alternatively, it


may suggest that, due to stress, such drivers are more likely to participate in dangerous

driving behaviours such as speeding or cutting off, which may be considered aggressive

by other road users.

4.3.5.1.4 Driving Stress.

Four participants made general reference to driving stress and its effect on

aggressive driving behaviour (see Table 4.11). Participant responses intimated that this

stress can result in a heightened attention to the on-road behaviour of other road users.

Table 4.11 Participant responses relating to driving stress

Quotes

n

General “…I think driving in itself is a really stressful thing to do. I’m always on the lookout for bad drivers”(MB26) “…driving can be stressful, because you are watching everyone else because your life can be taken in a second.”(FM5)

4

4.3.5.2 Trait Factors

In addition to the state person-related characteristics, a driver brings to the on-

road environment trait characteristics which are more enduring and/or permanent aspects

of their person or psychology e.g. age, gender, personality and general attitudes.

4.3.5.2.1 Age and Gender.

A number of participants (n = 11) spoke generally about a perceived lack of

patience and tolerance among younger drivers on the road. This lack of patience is

believed to contribute to feelings of frustration and anger being experienced by ‘other’

more experienced drivers, sometimes resulting in aggressive driving behaviours. Within

this group, six individuals spoke of a lack of driving skills and ability due to

inexperience, inherent in the young driver group (refer to Table 4.12). Coupled with a

lack of skills or abilities, it was suggested by two participants that young male drivers in

particular, drive as if nothing adverse will ever happen to them.

With reference to the young driver group, four participants emphasised young

male drivers and their involvement in aggressive driving behaviours (see Table 4.12).

Reference was also made to older drivers as a potential source of frustration and/or


anger on the roads (see Table 4.12). Specifically, participants referred to elderly drivers

as driving too slowly or having reduced ability and judgement whilst driving. As such,

this may indicate a lack of tolerance by young drivers for elderly road users.

Table 4.12 Perceptions of young drivers and other road users

Theme

Quotes

n

Inexperience “I think it’s a general lack of tolerance by drivers. They don’t have any patience…I think they should have more understanding and patience for learner drivers.” (FN2) “Inexperience with driving…well, my brother is inexperienced and he has had his licence for about a month and he thinks he is invincible, and he smashed his car up. A lot of my friends they get their licence and automatically think they can drive on the roads doing whatever they want. I think it’s inexperience that has a lot to do with behaviour.” (FT14)

6

Young Males “…a lot of my friends can drive aggressively without losing total control, like there might be danger to others on the road, but I think that is labelled as aggressive driving.” (MT4) “…I think it’s a male thing to do.” (FT24)

4

Older Drivers “And when you get stuck behind a car and they are old and they are doing 40 and it’s a 60k zone and … …god that annoys me.” (FL5) “ …old people in the wrong lanes…I hate that.” (FT14)

6

These findings suggest that many drivers make frequent use of stereotypes in the

interpretation of ‘other driver’ behaviour. Indeed, the young drivers in the sample

tended to maintain that they are more likely to be treated with intolerance and

impatience on the road.

4.3.5.2.2 Personality.

In keeping with previous traffic research, participants (n=8) also referred to an

innate propensity among some drivers to behave aggressively when driving (Table 4.13,

Quote 1) (Deffenbacher, Huff, Lynch, Oetting, & Salvatore, 2000; Deffenbacher,

Lynch, Filetti, Dahlen, & Oetting, 2003). A trait disposition for aggression is considered

a facet of personality (Quote 2). It was also suggested by six participants that

personality may contribute to an individual’s willingness to interpret aberrant driving


behaviours as intentional as opposed to merely an error, illustrated by Quote 3, Table

4.13.

Table 4.13 Participant references to personality tendencies for aggressive driving

behaviour Quote

Number Quotes n

1

“I think you can think of driving behaviour as like an expression of personality.” (FC12)

2 “People who are aggressive…like people that are aggressive when they are driving they don’t care about what they are doing and whether it might hurt some other person or cause someone to have an accident.” (FN2)

3 “I think a lot of it depends on the actual person…whether you are a calm person and more likely to think that what they did was just a mistake, and whether you are ready to forgive that, realising that other drivers do make mistakes.” (MA5)

8

4.3.5.2.3 Prior Learning.

Seven participants spoke of their prior exposure to perceived risk factors for

aggression that may contribute to aggressive driving behaviour (refer to Table 4.14).

As indicated at Table 4.14 (Quote 1), one participant spoke of her personal

exposure to aggression and violence in her family of origin. In the focus group, this

participant also reported that she had perpetrated an act of highly aggressive driving,

which resulted in a serious road crash. This particular incident will be discussed in

more depth in Section 4.3.5.3.

Table 4.14 Prior exposure to aggression cited by participants

Quotes

n

Family “My dad is an angry man…and he was hard to live with, he was so angry all the time. Dad is a redhead Scot, he is violent, so violent. He lashes out all the time.” (FL5) (Quote 1)

1 Other Aggressive Drivers Television

“…I think it is if you have always driven with people who suffer road rage or are unruly behind the wheel, then perhaps you are going to be as well.” (FC3) (Quote 2)

“He would watch sports on TV and probably learning from it…he would go and do doughies and he got busted by the cops (once) and he never did that again.” (MG4) (Quote 3)

2

4


4.3.5.2.4 General Attitudes About Other Drivers.

In addition to the responses outlined at Figure 4.2, the question ‘What do you

think are the main causes of aggressive driving?’ unveiled a theme, which has been

labelled ‘general attitudes’. These ‘attitudes’ re-emerged intermittently when

participants were asked ‘What do you think aggressive driving is?’ and , ‘Specifically,

what was it that prompted your feelings/behaviour?’. Table 4.15 presents a list of the

general attitudes of ‘other drivers’ identified by participants as contributing to aggressive

driving behaviour.

Table 4.15 General attitudes of the ‘other driver’

General Attitudes

n n Lack of care and consideration

29

Intolerance

6

General lack of courtesy

10

Antagonism

12

Inattention

10

Impatience

12

Rudeness

5

Lack of driving knowledge/skill

13

Bullying

4

Misjudgement of timing

3

Intimidating

7

Recklessness

12

Stupidity

10

4.3.5.3 General Transfer of Emotion to the On-Road Environment

Initially, in an open question directed to each focus group, participants were

asked ‘can you think of an instance where you got into your car upset/tense or angry?’

As an extension of the exploration of RQ1, this question was aimed at exploring the

potential for transfer of emotions to the on-road environment. A total of 18 participants

indicated that they had experienced a transfer of off-road generated stress to the on-road

environment. They were then asked how it had affected their subsequent on-road

behaviour. Table 4.16 outlines relevant quotes amongst the responses.


Table 4.16 Sources of off-road emotion transferred to the on-road environment Source of Off-Road

Emotion

Quotes

n Argument with Significant Other

“ Having had an argument with my partner, I felt really enraged… …I’m sure I was going faster than I needed to…breaked harder and drove faster, generally just threw the car around a bit more. Just drove a little harder.” (MD1) “Just recently on Sunday I had a disagreement with my boyfriend before going out and as I was driving to the city I was just not concentrating, just going into robot mode driving, while I was just thinking about the argument and I realised I just wouldn’t have noticed if (something had happened).” (FC22)

7

Driving to Reduce Stress

“I can get in the car and I’m driving and I calm down.” (FN4) “I find to go fast is good stress release.” (FJ5)

2 ‘Bad day’ at Work

“I had left Uni and I had had a really bad day. I just wanted to get home, so I was speeding. I remember thinking I felt like I was driving aggressively.” (FJ4)

2

Running Late for Work/Appointment

“When you are in a rush to get somewhere and someone is holding you up. You drive as quickly as you can, and take every opportunity and space to move quicker.” (FK3)

6 Fatigue

“I think sleep deprivation. People that work shift and don’t get enough sleep. I think my driving ability went down when I was on night shift and my tolerance for other drivers as well.” (MB26)

2

Among the off-road causes that were reported to have affected their on-road

behaviours were:

• having argued with a significant ‘other’;

• driving with the intention of reducing stress; and,

• having had a ‘bad day’ in general.

In many cases these factors resulted in feelings of tension and/or emotional

disturbance that resulted in the participant worrying or ruminating about the trigger

event whilst driving. The emotional upset and rumination, in turn, may have affected

their on-road driving behaviour with participants reporting the use of increased speed,

steering aggressively and subsequent sudden lane changes. Many of these participants

also admitted that they had paid insufficient attention to the on-road environment and

had little, or no, care for other road users.


These reactions were also reported in response to feeling under pressure, when

running late for work/appointment (n = 6). Another two participants reported feeling

fatigued having worked for an extended period, resulting in heightened levels of

irritability.

Two participants indicated that although they believed they had transferred their

negative emotions to the on-road environment, they became more vigilant about the on-

road environment. They also reported attempts to reduce the negative affect. For

example:

“…but I think it actually made me more careful about my driving. I didn’t want

to have an accident. So I put the issue out of my head and tried to focus on the

road and the music on the radio.” (FJ1)

4.3.5.4 Transfer of On-Road Generated Stress to the Off-road Environment

The final focus group questions posed to each group were:

• ‘Following an aggressive driving incident, have any of you felt

upset/tense or angry after you finished driving?’; and,

• ‘How did this affect your off-road behaviour?’

Eight participants believed they had not experienced any spill-over affect to the

off-road environment. However, a total of 28 participants reported that they had felt

upset, frustrated/angry after having finished a journey in which they had experienced

aggressive driving. Specifically, some of these participants (n = 13) suggested that the

on-road incident negatively affected their mood off-road. For example:

“…when I feel upset or angry on the roads I think I am grumpy also out of the

car.” (FS1)

“I think it effects how you are towards other people.” (FK4)

Five of these participants suggested that the resultant negative affect had

impacted on subsequent interpersonal interactions, though not markedly. Three female

participants reported feeling ‘upset’ to the extent that they were reluctant to drive the

following day.


It should be noted however, that a large proportion of participants (n = 19) spoke

of what may be considered ‘coping strategies’ (see Table 4.17). Six participants

reported feeling substantially better having discussed the incident with family or friends,

whilst eight spoke of improved affect upon arrival at their destination e.g. home.

However, one participant admitted to going to a hotel after his journey as a way of

reducing his stress. Three participants reported having put the incident out of their mind

upon alighting from their vehicle and/or commencing another task (see Table 4.17).

Table 4.17 Coping strategies adopted following an aggressive driving incident

Coping Strategies

Quotes

n

Discussing with Family or Friends

“Usually, once I talk about it I am fine.” (MR3)

6

Arrival at Destination Commencement of Other Tasks

“I think as soon as you get home you walk in the door and for me…it all goes over your head, you’re home, you’re safe, you’re happy. It’s your home.” (FT14) “Sometimes you might have a bit of road rage and you go home and shut your door on your car and you are fine.” (MT4) “…you know, you go into routine (when you arrive at work) and start your job…it’s only while I am in the car and it’s happening.” (FN4)

8

3

Finally, in the exploration of the transfer of on-road generated emotion to the off-

road environment, eight participants alluded to an accumulation of negative affect. For

example:

“The bad traffic on the way to work and then you have a bad day at work and then traffic on the way home…it just adds up.” (FJ4)

4.3.6 Personal Experiences with Aggressive Driving

Participants were asked to recall a personal experience with aggressive driving

behaviour. They were free to recount an experience as either a victim or the

perpetrator. Responses were anticipated to add to the information gathering relating to

RQ1 as well as RQ2, which aims at exploring the characteristics of those drivers more


likely to engage in aggressive driving. The following section is guided by the main

principles of the GAM as illustrated in Figure 3.1.

4.3.6.1 Victims or Perpetrators

When asked to contribute their personal experience with aggressive driving, 23

participants (9 males and 14 females) cited instances where they themselves were the

victim of aggressive driving behaviour. Twenty-one participants (10 females and 11

males) were able to recall instances where they perceived themselves the perpetrator.

The decision to categorise a participant’s role as either victim or perpetrator of

aggressive driving was based on the behaviour adopted and the level of intent to engage

in such behaviour. However, this was not difficult or demanding as the recalled events

and participant’s role in the incident were self-evident.

Fourteen participants initially attempted to reassure the researcher that they were

‘passive drivers’ or not at all likely to become aggressive on the roads, indicating a

desire to be perceived positively. However, despite their claims, use of probing

questions revealed that most of these participants had an experience to recount as either

the victim or the perpetrator. For example:

“I sort of class myself as a ‘passive driver’, my friends call me ‘driving Miss

Daisy’.” (some time later in response to another question, the same participant

responded…)

“ If I am driving and someone really pisses me off by cutting in on me, I will

catch up with them or flash my lights at them or give them the royal salute.”

(FN4)

4.3.6.2 Type of Road

Within the personal accounts of aggressive driving, not only were city and

suburban roads (n = 24) cited as the location for the incident, but highways (n = 10) and

country roads (n = 3) were cited in a number of incidents. This may suggest that

although aggressive driving may be more prevalent on city or suburban roads, it can

occur on all types of roads.


4.3.6.3 On-road Behavioural Causes

The following behavioural causes were elicited in response to the question:

• “Can you think of an instance where you may have acted angrily on the

road or responded angrily to someone?”

These figures include both victim and perpetrator accounts. The occurrence rates

for on-road precipitating behaviours cited in the personal recounts are recorded in Table

4.18.

Table 4.18 On-road precipitating behaviours from personal experiences with

aggressive driving Precipitating Behaviours n

Failure to stop/give way 12

Tailgating 11

Cutting in/off 9

Speeding 8

Getting out of vehicle 3

Delay at lights/signs 3

Not allowing merge 3

Overtaking 3

Slow driving 2

High-beam flashing 2

Misuse/lack of indicator 2

Horn honking 1

As was anticipated, the cited behaviours were similar to those behaviours

outlined in Figure 4.2. The most frequently cited behaviours were failing to stop/give

way, tailgating, and cutting-off. Most often, participants cited these behaviours in

combinations. These findings are consistent with the earlier, general causes identified


by the focus groups. When one or more facilitating factors are combined, the likelihood

of these behaviours being perceived as aggressive by an observer appeared to increase.

There were some specific instances where participants perpetrated aggressive

driving without any apparent on-road provocation. These instances were explored by a

later question relating to the transfer of aggression from the off-road environment to the

on-road environment. Therefore, given the absence of specific on-road causes in these

cases, six personal accounts from the perpetrator perspective have not been included in

the results at Table 4.19.

Further to exploring the behavioural causes, participants were asked to recall

specifically what it was about the ‘other driver’s behaviour’ that prompted their feelings

of frustration or anger (see Table 4.19). A number of participants (n = 6) cited the actual

behaviour as the catalyst for their feelings. However, the majority of participants cited

factors that indicate a strong interpersonal element (refer to Table 4.19). For example,

three participants reported that their feelings of anger were triggered specifically by their

frustration with the inability to communicate adequately from within the confines of a

vehicle and associated feelings of being misunderstood (Table 4.19).

Other participants indicated their feelings were prompted by the dangerousness

of the situation (n = 6) (Table 4.19) and associated feelings of threat, fear or shock (n =

5). Another three participants reported similar feelings being triggered by the ‘other

driver’ intending to or actually alighting from his vehicle (Table 4.19).

Interestingly, ten participants spoke of their feelings of anger being triggered

specifically by the attitude of the ‘other driver’ (Table 4.19). They spoke freely of the

other driver being rude, ‘cocky’ or ‘pushy’. These attitudes were apparently detected by

participants through verbal abuse (n = 7) and by the facial expressions of the ‘other

driver’ (n = 6). Further, three of the participants spoke of feeling specifically harassed

or pressured by the ‘other driver’. For example:

“I feared for our safety and maybe a bit pressured by him.” (MA2)

“I felt pressured not to wait and I was a bit shaken after that…” (FT3)

These findings suggest that negative on-road interactions may trigger feelings of

frustration, anger, threat or fear in young drivers.


Table 4.19 Frustrating or anger-provoking behaviour of other drivers

Quotes

n

Inability to Communicate Effectively

“They finally moved over (lanes). They had been quite aggressive toward me before that. …they thought I was trying to give them trouble. I was just trying to communicate with them.” (FA1)

3

Sense of Dangerousness

“Bit to do with anger and the fact that my adrenaline was pumping because I was nearly involved in an accident…because 2/3km down the road I started shaking a little bit.” (MN3)

6

Alighting from Vehicle

“…he was still going off at me for ages and I was going ‘oh, you shouldn’t have been speeding anyway’, and he said ‘pull over’, so I pulled over. Then he went in front of me and stopped (to get out) and I indicated to pull over but I just sped off instead, then I thought ‘oh, my gosh he might come after me’, so I did 120.” (FQ6) “Not so much the beeping and the flashing, but when he actually got out of the car, it was really scary.” (MA2)

3

Perceived Attitude of Other Driver

“Just that he was so smart and so sure (of himself), and I didn’t want a bar of it…” (MP2) “Apart from thumbing his nose at us…it was pretty much close to an accident as well.” (MP6) “…because he was flying around the roundabout and looked back and smiled at me. So he knew what he had done, and he was just being a real pig. That was pretty damn rude. The look is what made me really angry.” (FM5)

10

4.3.6.4 Pre-event Emotional State

As mood or ‘present internal state’ have been highlighted as relevant to

aggressive behavioural responses in general (Anderson & Bushman, 2002), young

drivers were asked how they were feeling immediately prior to their personal encounter

with aggressive driving. This question was intended to extend exploration of RQ1

examining what emotions, if any, participants bought to the on-road situation and RQ5

about the emotional and cognitive processes involved in aggressive driving.

Eight participants were unable to recall details of any specific feelings prior to

the on-road incident and 26 individuals recalled feeling ‘fine’ before the incident. It is

interesting to note that three of the latter participants indicated slightly higher levels of


positive emotion generated by a pending social event, singing along to music, and

‘cruising’ with others respectively, as shown in Table 4.20.

Table 4.20 Above average positive emotions reported prior to the event Due to Quote N

Pending Social Event

“I was coming home from work and I was going to a friend’s 18th birthday party that night. So…(I felt) pretty good actually.” (FA1)

Listening to Music

“(I felt) fine, the music was cranked and I was hitting the toe…so great.” (MP6)

Cruising with Others

“Just cruising. Travelling on with my brother, pretty groovy…” (MP2)

3

When participants reported a negative emotional state prior to the incident the

source of that stress was explored. Eleven participants reported being upset, tense or

angry prior to exposure to the provocative trigger and the generation of subsequent

feelings. Within this group, six respondents also spoke of feeling a little nervous about

driving prior to the on-road incident. Examination of their driving experience data

revealed that these participants were all newly licensed.

A further three participants reported feeling pressured as they were running late,

whilst four participants reported having had an argument with a ‘significant other’ prior

to the aggressive driving incident. This latter group reportedly experienced heightened

emotionality and/or anger, and these participants accounted for some of the more

extreme aggressive driving incidents.

4.3.6.5 Range of Emotions Experienced

Participants were asked to recall the range of feelings they experienced

throughout the recalled aggressive driving incident. Table 4.21 presents quotes that

illustrate some of these findings. A wide range of emotional responses to ‘other driver’

behaviours was identified by participants as the primary emotion.

Some of these emotions were felt in combination or in succession (refer to Table

4.22). For example, prior to the experience of these feelings, twelve participants

reported that they had felt harassed or pressured (n = 4), nervous (n = 2), worried about

safety (n = 2), offended (n = 1) or generally upset (n = 3).


Table 4.21 Range of primary emotions experienced

Range of Primary Emotions (n)

annoyed (11) scared (11)

frustrated (3) enraged (1)

angry (20) excited (3)

shocked (10)

After their behavioural response three participants reportedly experienced feeling

a sense of satisfaction or pride (n = 3) (refer to Table 4.22).

Table 4.22 Participant comments associated with range of emotions Emotions

Experienced Quotes n

Combined Emotions

“(It had) a bit to do with anger and the fact that my adrenaline was pumping because I was nearly involved in an accident. About 2/3 km down the road I started shaking a bit.” (MN3)

“My friends were hanging over the back thinking ‘oh he’s a bit cute’, so there was a bit of that going on…like ‘speed up girls the guy in the back is hot’. At the beginning it was a bit of fun, but it became something else…I was quite livid.” (FC3)

N/A Satisfaction or Pride

“…A bit smug, a little sense of pleasure. I didn’t think I was endangering them. I was just annoying them back.” (MD1) “I felt only a bit nervous, but quite proud of myself.” (FB6)

3

4.3.6.6 Cognitions During the Incident

Asked if during the incident participants recalled having any particular thoughts,

many were able to recall the main thrust of their thoughts (refer Table 4.23). A larger

number of participants (n = 28) recalled having made immediate negative appraisals

about the ‘other driver’.

In addition, ten participants recalled being primarily focused on the action they

intended taking (Table 4.23). These thoughts focussed on ‘getting back’ at the

‘offending driver’. Among these recollections were thoughts including physical abuse.

Other participants recalled thinking of how to remove themselves from the potential


source of danger (n = 2). For others the danger involved was their sole focus (see Table

4.23).

Five participants reported having what could be termed as ‘checking’ thoughts

(refer to Table 4.23). Such thoughts reflected that some participants were more likely to

reflect on their driving behaviour at the time of the incident, or upon their good fortune

at having avoided involvement in an accident. This may be an indication that some

participants tend to be more positive and/or reflective in their assessment of problematic

situations. A further five participants reported relatively neutral thoughts during the on-

road incident. These thoughts appeared to be non-personal, potentially reflecting a lack

of interest in blaming either party.

Table 4.23 Cognitions associated with reported aggressive driving incidents

Cognitive Themes

Quotes

n

Negative Attributions

“Who does this idiot think they are, ‘moseying’ along and holding traffic up like this?” (FJ1)

“Kind of like, ‘yeh, sucked in’. That is what was going through my mind…” (MR3)

28 Negative Actions

“…she kept sitting real close and following me and there was nothing I could do about it, but I thought to myself…alright, well I’m going to let her know that (she) has annoyed me.” (FN2)

“Yeh, I’m going to get you a beauty.” (FB6)

“He was going off and I was thinking, ‘oh (expletive)’. I was wondering if I could take him…” (MA2)

10

Escape/Danger

“I was thinking ‘what can I do to not get caught (by the ‘offending driver)?’ I was just concentrating on trying to find the best way out of it, to get away.” (MJ22) “I was just flooring it and I’ve never done anything like that before. Really fast…but even then I was thinking ‘oh, this is so dangerous’.” (MR4) “Just how dangerous it was.” (FC1)

2

2

Checking Thoughts

“I just thought I was pretty lucky I didn’t have a crash…” (MJ12) “When it happened, I wondered what I was doing wrong, but I was driving a bit faster than the speed limit so…” (MB16)

5

Neutral Thoughts

“I wondered, ‘why would you bother chasing someone that much?’ …I just thought ‘why would you bother to go to that much effort when you can’t really do anything about it?’” (MJ22)

5


4.3.6.7 Behavioural Responses to On-Road Provocation

At this point in the research process it was considered appropriate to distinguish

between displaced, suppressed or outward expressions of aggression consistent with

other research about aggressive driving in an Australian population (Lawton & Nutter,

2002). Table 4.24 illustrates participant behavioural responses consistent with these

descriptors.

Indicative of on-road reactions, six participants cited behavioural responses that

could be interpreted as displacement of aggression. That is, despite the experience of

negative emotion, no on-road action was taken (see Table 4.24). The displacement was

considered necessary in three cases, due to fear that the event may escalate in severity.

Table 4.24: Behavioural responses adopted by participants in response to perceived

provocation in recalled aggressive driving incidents

Behavioural Themes

Quotes

n

Displaced Aggression

“I don’t really know (what I had done). I was trying to get over into the other lane and she wasn’t going to let me. Next minute she was beside me screaming at me… (Behavioural Response) - I tried hard not to laugh because she looked funny with her mouth moving. She was saying enough for both of us.” (FC6)

6

Suppressed Aggression

“ I just think ‘oh, you idiot’ and keep cruising along…” (MJ22) “ I don’t get aggressive very much, I’m pretty happy all the time. I just say ‘good luck loser’.” (MC5)

10

Outward Aggression

“I jumped on the brakes, threw my car down two gears to stop the wheels locking up, threw my hand onto the horn and put my lights up onto highbeam.” (MN3) “…I was going about 50 up this hill and this guy came speeding up behind me and sat right up my arse, and I looked in my rear-view mirror…then when we came down the hill and I thought ‘hell yeh, I’m going to get you so bad right now’ and went even slower then…so I intentionally went really slowly...as he went passed I gave him the forks.” (FB6)

30


A number of participants (n= 10) reported behavioural responses consistent with

suppressed aggression i.e. aggressive thoughts (n = 3) and/or verbalisations made with

no intent of the ‘offending driver’ hearing it (n = 7). More female (n = 7) than male

drivers (n = 3) seem to participate in suppressed aggression in response to on-road

provocation. In the main, however, participants (n = 30) reported an outward

behavioural response to the on-road provocation (Table 4.24). Unexpectedly, more than

half of those who reportedly participated in outward expressions of aggressive behaviour

were female (16 females and 14 males). Table 4.25 outlines the frequency of the

specific outward behaviours adopted by participants. It should be noted that of the nine

behaviours reported, some of these occurred in combination.

Table 4.25 Outwardly aggressive behavioural responses to personal experiences with

aggressive driving


n

Tailgating

3

Overtaking

5

Speeding

5

Following of ‘offending’ vehicle

2

Slow driving

7

Verbal abuse

5

Highbeam flashing

2

Horn honking

7

Gesticulating

5

When a participant had engaged in an outwardly aggressive behavioural

response, they were asked if that response could have been interpreted as aggressive by

others. A large portion of participants (n = 20) indicated that the behavioural response


they adopted could be considered aggressive, six participants did not believe their

behaviour could be considered aggressive, and five participants were unsure.

These participants were also asked if their behaviour was intentionally aimed at

the ‘other driver’. Eighteen participants reported that their behaviour was ‘intentional’,

consistent with the inclusion of intention in the provisional definition outlined in

Chapter Two. A total of 27 participants expressed that they felt ‘justified’ in responding

as indicated.

4.3.6.8 Post-Event State

In an attempt to explore the duration of negative affect resulting from their on-

road aggressive driving experience and any possible influences upon subsequent

behaviour, participants were asked how they felt for the 15 minutes immediately

following the incident. They were also asked how they felt about the incident an hour

after the incident.

Four participants indicated that they had forgotten about the incident within 15

minutes of its occurrence. However, other participants reported a wide range of

emotions following the incident. In many instances participants reported that their

experience with aggressive driving resulted in the experience of more than one emotion.

For instance, 11 of the participants reported feeling annoyed or angry up to 15 minutes

immediately following the incident and six of them reported feeling simultaneously

upset, emotional or shaken during this time frame.

Three other participants cited feelings of relief at the potential danger having

passed, whilst two participants reported continuing to feel worried or frightened. A

further six participants reported feeling tense or ‘wound up’, and another two felt

‘excited’.

Three participants reported feeling ‘satisfied’ with having let the ‘other driver’

know they had behaved inappropriately on the road. It should be noted that as an

extension of these emotions, many participants (n=19) reported ruminating about the

event to some degree. For example:

“I was just thinking about it and pretty angry still.”(FM5)


When asked how they felt approximately one hour after the incident, a

considerable number of participants (n=25) reported not thinking of the incident again.

According to participant responses, this was primarily due to one or more of the

following:

• having forgotten about the incident after arriving at their destination;

• having commenced other tasks, such as work; and/or,

• having spoken about it with a workmate, friend or family member.

Some of those participants who spoke with a friend or family member about the

incident reported temporarily re-experiencing the emotions to some degree. For

example:

“I felt a bit wound up when I got home and I told everyone about it.” (FK1)

“Oh, I was still upset, but I was…calmer…I could (still) see it happening.

Thinking everyone is going to die, because no-one would let me in.” (FJ5)

Finally, six participants reported no change in their feelings for some time.

Without exception these individuals, usually the victim (n = 4), were those who had

been involved in more serious aggressive driving incidents which resulted in the

participant experiencing more intense negative emotions such as emotional upset or

shock accompanied with anger. For example, one participant who had been the victim

of a particular incident stated:

“…I called my grandparents about twenty minutes later and I was quite upset

about it. That feeling lasted quite a while.” (FA1)

4.3.6.9 Personal Accounts of Off-Road Stress Brought to the On-Road Environment

These results were referred to briefly in Section 4.3.5.3 (p.148). When

specifically asked to recall a personal experience with aggressive driving behaviour, six

participants offered detailed personal accounts of how an off-road trigger had

substantially affected their mood and subsequent on-road behaviour. One of these

participants reported feeling hyped due to ‘hanging’ with his friends and subsequently

‘cruising’ with them. Subsequently, an arguably minor transgression by another driver


prompted an aggressive response. This participant pursued and verbally abused the

‘other driver’.

“(Whilst merging into one lane and travelling with four mates)…but he kept

going, to the point where I had to slam on my brakes…everyone in the car is just

hurling abuse at him, but he was gone. So we were driving along and about five

minutes later we saw him and we pulled up beside him. At that point the five

guys in the car are just ‘OOOH’…so the windows went down and abuse was

hurled and we followed him for a while just because we had nothing better to do.

It wasn’t like we had a destination to go to.” (MP6)

Four of the participants offered accounts that had been triggered by an off-road

argument with a significant other. The resultant emotional affect was high levels of

frustration/anger, that in turn resulted in speeding and erratic driving behaviour. Three

of these participants were subsequently involved in motor vehicle crashes resulting in

personal injury and property damage. Two individuals who reported being involved in a

crash (1 male, 1 female) had been under the influence of alcohol and recreational drugs

respectively. These participants also reported having had little regard for other road

users at the time of the incident:

“I nearly lost my life...I wrapped my car around a pole. I was on a lot of social

drugs, had an argument with my partner…a big argument. It turned physical

and I decided to take the car and go driving. I wiped out a couple of cars, nearly

hit a few people……I was pretty much just fried in my head… I was so angry,

frustrated, smashing my hands on the steering wheel and came around the

corner and wrapped the car around a pole……anyone that was in my way was

going to cop it.” (FL5)

“The major one. I had just had a fight with my girlfriend. I was drunk…at a

rodeo and I decided to take off and done a few things (…coppers followed me out

of the rodeo grounds and I didn’t pull over, I just kept going) and lost my licence

for quite a while over that. I stopped after I hit them (with his vehicle)…” (MS5)


4.4 Discussion

This discussion is structured in accordance with the concept map outlined in

Figure 4.1. Where applicable, reference will be made to the relevant Research

Questions and how they have been addressed. A brief overview of the findings in

relation to the Research Questions is also outlined at Section 4.4.9 below.

4.4.1 Situational Factors

In relation to RQ1, the situational causes identified by this research do not differ

markedly from those identified in previous research (Lajunen & Parker, 2001; Shinar,

1998; VCCAV, 1999). The findings suggest that a combination of one or more

direct/indirect on-road situational factors increases the likelihood of on-road behaviour

being perceived as aggressive.

With reference to the general nature of the behavioural causes of aggressive

driving, participants indicated that if the behaviours outlined at Figure 4.2 are to be

considered aggressive they must also negatively impact upon, or have the potential to

negatively impact upon other road users. Moreover, when these behaviours are

perceived as being intentionally perpetrated they are then considered aggressive driving

behaviours. Thus, the results suggest that these behaviours may be considered

aggressive when an element of ‘danger’ is involved and when the behaviour is perceived

to be intentionally adopted, consistent with the provisional definition of aggressive

driving at Section 2.2.5.3.

Driver perception of other vehicles is also a factor to be considered in aggressive

driving. Seventy-four per cent of participants spoke of specific types or characteristics

of vehicles they believe will be more readily identified with aggressive driving. For

instance, larger or mechanically modified vehicles were believed to increase the

likelihood of driver behaviours being identified as aggressive. Although some

participant comments could be considered no more than stereotypes, they are the

perceptions of the participants, and perception appears to play a pivotal role in

aggressive driving.

Fifteen per cent of young driver participants also perceived an increase in the

number of vehicles on the road, as well as a general increase in the pace of living,

suggesting that these perceptions contribute to the generation of frustration/anger


associated with road use and ‘other driver’ behaviours (Shinar, 1998). Participant

comments related to driving whilst under ‘time pressure’ indicated that young driver

behaviour may become more aggressive as they may use greater speed and overly

assertive behaviours to gain time. In addition, these drivers will more readily interpret

‘other driver’ behaviours as ‘goal blocking’, consistent with previous research (O’Brien,

Watson, & Tay, 2005. Finally, as in other traffic related research, substantial evidence

was found of young driver behaviour being negatively influenced by the presence of

peer passengers (Doherty, Andrey, & MacGregor, 1998).

4.4.2 State and Trait, Person-Related Causes

The focus group participants reported a range of person-related factors

considered to influence aggressive driving, which provides interesting insights into RQ1

and RQ2. In the face of exposure to the factors identified, 26% of the participants

suggested that the ‘state’ or mood a driver brings to the road has the potential to

influence driver perceptions of the facilitating factors as aggressive or otherwise. They

also suggested a temporary, negative mood state brought to the on-road environment

may increase the likelihood of dangerous driving practices. This is consistent with other

research (Matthews, Dorn, & Glendon, 1991; Novaco et al., 1990). Negative mood also

appears to increase the likelihood of perceiving ‘other driver’ behaviour as aggressive.

Longer lasting stress, such as life stress or employment stress, seems to have similar

effects upon driver perceptions and behaviour (Cartwright et al., 1996; Selzer &

Vinokur, 1975).

The results suggest that young drivers, as an at-risk group, may also tend to

ruminate about on and off-road stressors. Twenty-three per cent of the young drivers

reported thinking about their experience with on-road aggression for some time. A

number of participants also continued to think about off-road stressors whilst driving

(40%). As a consequence, ruminating drivers appear to pay reduced attention to the on-

road environment. However, for some young drivers the effect of driving stress may, at

times, markedly increase the amount of attention paid to the on-road environment and

the behaviour of others. As a result of this, some young drivers may become

‘hypervigilant’ and primed to perceive ‘other driver’ behaviour as aggressive or

dangerous (Zillmann, 1988).


Within the confines of stereotypes, 9% of the young driver participants perceived

young male drivers as the main offenders in aggressive driving incidents. However,

15% also appear to perceive themselves as being subject to a ‘lack of patience’ by the

more experienced driving population. At the same time, however, a number of young

drivers (15%) indicated a lack of tolerance for elderly road users.

The participants also spoke of the trait characteristics a driver may bring to the

road, suggesting that these characteristics negatively influence driving behaviour and the

perception of ‘other driver’ behaviours as aggressive and/or intentional. Such person-

related traits include personality and trait aggression levels, consistent with other traffic

research (Deffenbacher, Huff, Lynch, Oetting, & Salvatore, 2000; Deffenbacher, Lynch,

Filetti, Dahlen, & Oetting, 2003). Further to these suggestions, 15% of participants

referred to a driver’s prior exposure to aggressive driving behaviours and/or aggression

in the home, suggesting that some young drivers believe that aggressive responses are

learned, as is consistent with social learning theory (Bandura, 1972). The review of risk

factors for the development of aggressive and anti-social tendencies also supports this

observation as valid (Bor, McGee, & Fagan, 2004; Borum, 2000; Cairns, Neckerman,

Gest, & Gariepy, 1988; Caspi, 2000; Coccaro, 2003; Farrington, 2000; Farrington,

Loeber, Yin, & Anderson, 2002).

Finally, multiple observations were made by participants about the general

attitudes that a driver may bring to an aggressive driving incident (refer to Table 4.15).

These ‘other driver’ attitudes are believed to contribute to feelings of frustration and/or

anger and increase the likelihood of an aggressive behavioural response by participants.

4.4.3 Range of Emotions During an On-Road Incident

Focus group questions aimed at exploring the emotions and cognitions

experienced during participant experiences with aggressive driving assisted in the

exploration of RQ5. The results are discussed at both 4.4.3 and 4.4.4.

When on-road behaviours are interpreted as provocative, a wide range of

emotions are reportedly experienced. This study strongly suggests that the experience of

frustration and/or anger in response to an on-road situation, as suggested by Shinar

(1998), are not the only precursor emotions influencing aggressive driving behaviour in

the young driver group. Emotions such as fear, nervousness, anxiety and excitation also


appear to influence aggressive driving behaviour. This indicates that the assumption that

aggressive driving behaviour comes purely from feelings of frustration/anger may be

potentially limiting our understanding of this phenomenon.

For instance, the inclusion of excitation as a precursor emotion to aggressive

driving behaviour appears reasonable when considering the small, but relevant, number

of young male drivers who reportedly participate in social/recreational driving practices

with peers. It is not difficult to imagine that driving with peers may contribute to

elevated feelings of excitation or arousal. It would be consistent with Zillmann’s

excitation transfer theory (1972) that this elevated state may lead to the perpetration of

potentially dangerous or impulsive on-road behaviours such as driving at high speed,

that has the potential to be interpreted as aggressive by others. The elevated state

leading to the interpretation of other driver behaviours as aggressive and increasing the

likelihood of an aggressive response, would also be consistent with excitation transfer

theory (Zillman, 1972).

The results also indicate a small but noteworthy difference in the emotions

leading up to aggressive driving behaviour. Although a large number of females

reportedly experience similar levels of frustration/anger to males, the results suggest

more female victims than males are likely to experience fear and feelings of

intimidation.

4.4.4 Cognitions During an On-Road Incident

When exposed to a potentially anger-provoking on-road situation, these results

also indicate that young drivers appear quick to make negative attributions about other

drivers and their abilities. Such negative attributions made by a driver may increase the

possibility of perceiving another’s actions as aggressive and increase the likelihood of an

aggressive response (Lennon, Watson, Arlidge, & Fraine, under review; Yagil, 2001).

Although Yagil (2001) found that the perception of negative attributions tend to act as a

catalyst to aggressive driving, there is no empirical evidence to date that suggests that

young drivers are more likely to assume negative attributions than older drivers. This

study also identified another, less frequent, form of thought reported by drivers during

an aggressive driving incident. These thoughts centred around ‘negative actions’ that

may be adopted towards the ‘other driver’.


In review of the cognitions associated with an on-road incident, it became clear

that there was little or no reference to some elements contained in the GAM appraisal

and decision-making model (Figure 3.2) (Anderson & Bushman, 2002). For example,

no participants reported having ‘checked’ if available resources were sufficient to deal

with the situation or if the outcome was important or satisfying to them prior to their

action/response. However, this does not mean that these checks are not made at a deeper

cognitive level that is unable to be recalled, as suggested by Anderson and Bushman

(2002). For example, for the 11% of individuals who reported relatively neutral

thoughts associated with the on-road incident, a response does not appear to have been

important, and the resultant lack of an outcome did not appear to concern them. Such a

finding may be interpreted as consistent with the decision and appraisal model proposed

in the GAM (Anderson & Bushman, 2002) that maintains that if an ‘outcome’ is not

overly important or satisfying to an individual then the expression of aggression is less

likely. Despite this, however, the findings indicate a substantial lack of remembered

decision making associated with aggressive driving.

4.4.5 Behavioural Responses to On-Road Provocation

Participant responses to questions aimed at exploring possible behavioural

responses to on-road provocation highlighted that a range of behaviours are possible.

The results assisted in the exploration of RQ2 and RQ5. In this study, severe cases of

aggressive driving that culminated in crash involvement or physical injury to a driver

appear few. However, this could be considered consistent with previous aggressive

driving research that suggests severe cases are indeed quite rare (Elliott, 1999; VCCAV,

1999).

The findings suggest there may be a small difference in the types of on-road

aggression in which male and female participants are prepared to engage. Firstly, more

young female drivers seem to participate in suppressed aggression than do young males.

This is consistent with previous research that suggests differences in male/female

expression of driver aggression (Lajunen & Parker, 2001). However, the current study

also revealed that female drivers are prepared to engage in outwardly aggressive

behavioural responses to on-road provocation e.g. gesticulating or verbal abuse (Section

4.3.6.1). Overall, there does not appear to be a substantial difference between male and


female involvement rates in aggressive driving as either victims or perpetrators

(perpetrators: 11 males, 10 females, and victims: 9 males, 14 females).

This research suggests that young driver behavioural responses to on-road

provocation vary due to the intensity of that provocation, and the degree of

dangerousness it presents. Indeed, these factors appear to be important when

considering any on-road behaviours associated with this phenomenon.

4.4.6 ‘Post Event State’ or Transfer to the Off-Road Environment

Evidence was found to support the concept of an altered ‘post-event state’

(Anderson & Bushman, 2002) after experiencing an aggressive driving incident (or

transfer of emotion to the off-road environment) that may influence a driver’s

subsequent behaviour. Not only does this ‘post-event state’ have the potential to affect

off-road interactions, but it has the potential to continue to accumulate whilst remaining

within the on-road environment, possibly influencing on-road behaviours at a later time.

Review of the findings suggests that on-road generated emotion may be

transferred to the off-road environment. However, it seems that the possible changes in

off-road behaviours are not overly severe or lasting. For example, the experience of

extreme on-road generated frustration/anger may affect subsequent off-road interactions

with others, but not to the point where physical or verbal abuse may result, although it

appears that some young drivers, particularly females, may experience continued

distress or a form of distraction due to ruminating about the incident. Clearly, the

consequences of transferring negative emotions to the off-road environment appear

relatively minor and infrequent. As suggested by this research, removing oneself from

the road environment and the task of driving seems to reduce and/or nullify residual

negative emotion in most cases.

4.4.7 Transfer of Emotions to the On-Road Environment

In the young driver group, it appears that off-road generated stress is frequently

transferred to the on-road environment. When faced with ambiguous or provocative on-

road situations, participant behavioural responses appeared to be impulsive and/or

reactive. The resultant heightened emotional states resulting from off-road causes may

also account for unprovoked on-road aggressive behaviours being perpetrated by young

drivers. Highlighted within some participant experiences was an apparent lack of


constructive coping strategies. For example, as opposed to discussing or expressing

their ‘bad day’ at work, some drivers proceeded to drive home quite agitated thereby

affecting the way they drove their vehicles. This response may be inherent in younger

drivers due to their general lack of life experience and exposure to a wider range of

coping strategies.

Further exploration of transference also found that young drivers may use

‘driving’ itself as a coping strategy for daily off-road stressors. For example, in addition

to two participants indicating that they drive to reduce off-road generated stress, a

further seven admitted to ‘escaping’ in their vehicle following an argument with a

‘significant other’ in their life. This suggests that when young drivers are faced with

considerable off-road stress, they may be more likely to use their vehicle as a means of

escape, avoidance or release from the stressor. A potential consequence of such a

transfer can be aggressive driving behaviour.

In general, the findings support the suggestion of transference of negative affect

to and from the road environment. In general aggression research, the transference of

aggression from one situation to a subsequent situation is more commonly known as

displaced aggression (Pedersen, Gonzales, & Miller, 2000; Marcus-Newhall, Pedersen,

Miller, & Carlson, 2000). More specifically, one of these studies found that provoked

individuals will respond more aggressively to a subsequent trivial trigger, than those

who were not originally provoked (Pedersen et al., 2000).

Ultimately, the findings of this study identified a number of both ‘on’ and ‘off-

road’ factors that have the potential to contribute to young driver aggression. It appears

that young drivers may engage in on-road aggression in two possible ways:

• Using a vehicle and the on-road environment as a means of expressing

off-road generated stress; and/or

• Whilst driving, responding to provocative actions that are encountered in

the on-road environment.

4.4.8 Coping Strategies Adopted by Young Drivers

Whilst exploring the phenomenon of aggressive driving, participants also spoke

of coping strategies they have adopted in order to deal with residual, on-road generated

anxiety or stress. For instance, 15% of young drivers spoke of improved mood having


discussed their experience with family or friends or after beginning other tasks. Some

young drivers (15%) spoke of the potential of music to enhance or mediate their internal

state whilst driving. Another 11% of participants demonstrated more rational responses

to aggressive driving by adopting ‘checking’ thoughts. This involved questioning the

accuracy or validity of their driving behaviour.

In summary, the findings of this study highlight coping strategies as an important

issue, which may assist in our understanding of the apparent over-representation of

young drivers in aggressive driving research. Perhaps it should be considered that

young drivers, as young adults, have a limited range of coping strategies available to

them when compared to older drivers. This is consistent with previous research into

young driver behaviours and risk taking (Jonah, 1997). As Jonah (1997) suggested, high

levels of on-road risk taking, more prevalent in young male drivers, may be a

developmental issue.

4.4.9 Addressing the Research Questions

The following discussion will summarise the study findings relevant to the

particular research questions identified in Section 4.1.


driving?

Many person-related and direct/indirect situational factors were cited as potential

contributors to aggressive driving, most of which were consistent with those identified in

the literature review. Although less person-related factors were identified than ‘on-road’

situational factors, the results suggest they are extremely important to the perception of

other driver behaviours and ultimately the behavioural outcome adopted by drivers.

Several factors previously identified as contributing to aggressive driving were also

identified. Among them were characteristics such as vehicle appearance and/or

modifications (Evans & Wasielewski,1983), size of a vehicle and travelling with peers

as passengers. Within the person-related factors, young drivers emphasised ‘mood’,

possible prior exposure (i.e. prior learning through other driver behaviours), stereotypes

and general attitudes. As such this study has added to the knowledge of potential factors

influencing aggressive driving among the at-risk group of young drivers.


RQ2 Are some drivers more likely to engage in aggressive driving and, if so, what are

their characteristics?

Although this study identified several young drivers who had reportedly engaged

in highly aggressive behaviour on the road, only socio-demographic data was collected

from each participant. However, the general person-related factors identified by

participants as influencing aggressive driving (see Figure 4.2), provide an insight into

the person-related characteristics that young drivers typically associate with aggressive

drivers. As such, these person-related factors require further investigation in the next

study.


behaviours?

Consistent with the distinction of types of on-road aggression as outward,

suppressed or displaced (Lawton & Nutter, 2002), this study found that a number of

young drivers adopt suppressed or displaced responses whilst driving. However, the

majority of both male and female young drivers reportedly engage in the outward

expression of aggression whilst driving (see Table 4.25). In answer to the research

question, the study suggests that on the surface the three methods of responding

examined by Lawton and colleague (2002) (i.e. outward, displaced or suppressed) are

not directly related to one another. Indeed, displaced or suppressed aggression appears

less likely to manifest in aggressive driving behaviour on the road. If the types of

outward behavioural responses adopted are examined alone, however, they appear to fall

into two categories in keeping with the instrumental/hostile distinction made by Shinar

(1998). Nonetheless, all of these behaviours may be considered instrumental or hostile

dependent on the context of the situation. Hence, this research question requires closer

examination in Study Two.


In response to this research question, the study findings suggest that for young

drivers, aggressive driving behaviours appear to serve several functions. Not only

would it appear to assist in overcoming obstacles to their on-road progress (Dollard et

al., 1939; Shinar, 1997), for some drivers they appear to serve more salient functions,

such as catharsis (Dollard et al., 1939) or a behavioural expression of high levels of


emotionality (Chang et al., 2003; Cummings et al., 2004; Loeber et al., 2001; Verona et

al., 2002). Additionally, the results suggest that some young drivers use their vehicles

and the on-road environment as a venue, however inappropriate, for the expression of a

wide range of emotions from frustration to excitation. Why young drivers adopt

aggressive driving behaviours when travelling with peer passengers is speculative.

However, whilst surrounded by their peers, perhaps it serves to demonstrate their driving

abilities or to inflate their self-esteem.


driving behaviour?

As detailed in Section 4.4.3, frustration and anger may not be the only emotions

associated with aggressive driving behaviour. Young drivers also reported experiencing

fear, nervousness, anxiety and excitation during episodes of aggressive driving.

Additionally, when discussing their own experiences with aggressive driving, the young

drivers in the study appeared quick to make negative attributions about other drivers and

their abilities. A small number of participants also reported having thoughts about

taking action against the other driver. These findings will be investigated further in

Study Two.

4.4.10 Strengths and Limitations of the Study

The current study has examined aggressive driving from within the framework of

the contemporary human aggression theories encompassed in the GAM (Anderson &

Bushman, 2002). The results of this study and the foregoing literature review have

identified some of the psychological characteristics of aggressive drivers. The study has

also identified several factors that appear to contribute to the perception of aggression by

young drivers, including stereotypes of young drivers and young driver participation in

social driving practices. Not surprisingly, the results also clearly highlighted the

importance of state and trait person-related characteristics of drivers in the perception of

‘other driver’ behaviours as aggressive or provocative.

The research provides valuable insight into the phenomenon of aggressive

driving from the perspective of young drivers i.e. those drivers who have been

repeatedly over-represented in aggressive driving (Harding et al., 1998; VCCAV, 1999).

Unfortunately, as the focus group participates comprised only young drivers aged 17–24


years of age, generalisation of these results to the greater population of drivers is not

possible. In addition, there may also be limitations in the generalisation of these

behaviours to young drivers, as the majority of research participants were ‘city’ drivers

and relatively inexperienced. As such, these limitations need to be borne in mind when

interpreting the findings.

4.4.11 Implications of Findings for the Development of a Psychosocial Framework for

Aggressive Driving

Guided by the Research Objective One identified in Section 1.7, the results of

this study suggest that elements of the GAM are valid and applicable to aggressive

driving. To assist in better understanding this phenomenon, however, it would be useful

to modify some of the concepts included in the GAM (Anderson & Bushman, 2002).

Figure 4.3 outlines the key psychosocial factors identified in the literature review and

this study as influencing the likelihood and nature of aggressive driving behaviour,

drawing on key components of aggression encapsulated in the GAM.

Figure 4.3 Theoretical framework of psychosocial processes underpinning aggressive driving

Present Internal

State

On-road Experience

Socio-demographic and Driving

Exposure Factors

State Person-related Characteristics

Emotional &

Cognitive Response

Negative Emotions

Threat

Negative

Attributions

Behavioural Response

Instrumental

Hostile

Post-event Influence Trait Person-related

Characteristics


Consistent with the GAM (Anderson & Bushman, 2002), trait and state person-

related characteristics are proposed to give rise to a ‘present internal state’ that drivers

bring with them to the task of driving. For example, an individual who has high trait

aggression levels brings this predisposition to the on-road environment (Deffenbacher,

Huff, Lynch, Oetting, & Salvatore, 2000; Deffenbacher, Lynch, Filetti, Dahlen, &

Oetting, 2001). Similarly, a driver who is experiencing state stress generated from work

or home life, may also bring this to the on-road environment (Navaco et al., 1990;

Wiesenthal & Hennessy, 1999).

This study’s findings also suggest that within the ‘present internal state’ a driver

brings to the on-road environment, heightened levels of ‘emotional arousal’ or

‘excitation’ may pre-exist at the beginning of the journey being undertaken. The

findings are consistent with the GAM and suggest that high levels of excitation resulting

from extreme negative affect or the presence of peers as passengers, may contribute to

an increased likelihood for aggressive on-road behaviours in response to a perceived

provocation. In the absence of a perceived on-road provocation, highly aroused drivers

may engage in potentially dangerous or impulsive driving behaviours, such as excessive

speeding. Previous research also demonstrated that low to moderate levels of emotional

arousal, measured in terms of depression, may serve to increase the likelihood of a

reactive, aggressive response to perceived provocation (Cooper et al., 1995). Consistent

with human aggression research (Berkowtiz, 1993; Florian et al., 1995) this research

also found that greater feelings of ‘threat’ in response to on-road provocation may also

result in aggressive driving behaviour. As such, the experience of a range of emotions

and the subsequent arousal associated with them, appears to increase the likelihood of

interpreting the on-road behaviour of ‘other drivers’ as aggressive, increasing the

likelihood of an aggressive response.

Whether or not they are highly aroused, in response to the provocative or

ambiguous on-road behaviour of ‘other’ road users, drivers appear to undergo an

automated appraisal process consistent with elements of the GAM’s decision-making

model and as suggested by the authors (Anderson & Bushman, 2002). However, the

‘checking of available resources’ contained in the original GAM appraisal process

remains largely subconscious and therefore it seems highly improbable that accurate


recall of these processes can occur (Anderson & Bushman, 2002). For this reason,

therefore, focus in the current study turned to the cognitions that were able to be recalled

when participants recounted their personal experience of an on-road incident. Thoughts

able to be recalled primarily centred around negative attributions about other drivers and

their driving abilities and/or thoughts of danger or threat. Hence, little reference was

made to the subconscious cognitive processes proposed in the GAM, within the

proposed framework at Figure 4.3. However, the findings of this study did highlight

three key elements of the ‘situational response’ to an on-road incident depicted in Figure

4.3: negative emotions, perceived threat, and negative attributions.

These key elements appear to have considerable impact on aggressive driving

outcomes. The findings of this study suggest that, in the face of perceived provocation,

or as a result of highly aroused driving, some drivers experience a negative emotional

response that will often be accompanied by higher levels of physiological arousal. It

also appears that upon perceiving provocation, drivers infer positive or negative

attributions about the ‘other driver’ behaviour and their abilities (Yagil, 2001). Further,

the results of this study also indicate that drivers may experience cognitions about taking

action. However, it should be noted that most thoughts recalled by participants as being

associated with the aggressive driving incident were considerably less detailed than the

cognitive appraisal process outlined in the GAM (Anderson & Bushman, 2002).

Having had an initial response comprising emotions, cognitions and arousal, the

GAM indicates that drivers will respond with either impulsive or thoughtful (deliberate)

behavioural responses (Anderson & Bushman, 2002). The current study was not

conclusive about this and it remains unclear whether participants were thoughtful or

impulsive in their responses. Notwithstanding this caveat, with reference to the

proposed framework, it could be that more impulsive behavioural responses are elicited

from participants who are more highly emotionally aroused prior to entering the on-road

environment. Alternatively, impulsive reactive behaviours may also originate within

participants high on trait impulsivity, not measured in this study (Caprara et al., 1987;

Stanford, Greve, & Dickens, 1995). Human aggression research suggests that drivers

who have low emotional arousal (or depression) and high levels of irritability, may also

experience high levels of frustration/anger when faced with an on-road provocation and


may also participate in impulsive, reactive aggressive behavioural responses (Caprara et

al., 1987; Stanford et al., 1995). However, not all participant responses cited in this

research can be explained by or reduced to ‘impulsivity’.

This research highlighted that many of the behavioural responses adopted by

drivers appear to be quite ‘deliberate or thoughtful’ i.e. intentionally driven, in keeping

with the provisional definition proposed in Section 2.2.5.3. Some deliberate behavioural

responses cited include quite extreme behaviours such as following a vehicle. However,

other deliberate behavioural responses appear to include the decision to remove oneself

from a perceived danger or not to have an on-road behavioural response. Despite these

findings it is clearly not always possible to determine whether the ‘decision-making

process’ preceding their behaviour response was ‘thoughtful’ or ‘impulsive’, as outlined

in the original GAM (Anderson & Bushman, 2002).

Finally, in relation to whether a behavioural response is adopted or not, this

research supports the concept of a residual ‘post-incident state’ resulting from

experiences with on-road aggression. In support of previous findings concerning the

cumulative effect of stressors, the resultant emotions, cognitions and arousal may

contribute to a new or revised, ‘present internal state’ for a driver (Anderson &

Bushman, 2002). As suggested by the findings of this study, the revised ‘present

internal state’ is then subject to temporal considerations. In keeping with the findings of

Fiendler and colleagues (1984), if enough time elapses, negative affect from the anger-

provoking event appears to dissipate. However, aggression researchers suggest that the

ready availability of the negative emotions associated with the ‘present internal state’ is

kept active/or easily activated by ruminative thoughts (Bushman et al., 2005). In this

regard, the study found that 23% of participants reported thinking about the event for the

15 minutes immediately following the incident. As such, it seems reasonable to posit

that the potential for further on-road aggression also remained.

4.4.12 Chapter Summary

This study was designed to explore the phenomenon of aggressive driving from

the perspective of a particular high-risk group, previously identified in the literature. In

doing so, the study identified a wide range of situational and person-related factors that

young drivers believe influence the likelihood of aggressive driving behaviour, many of


which were consistent with the available literature. Uniquely, this study also highlighted

elements of human aggression theory encapsulated in the GAM that appear relevant to

on-road aggression that have not previously been examined in other theory based

approaches to the phenomenon (Shinar, 1998). As such, a psychosocial framework

(Figure 4.3) for the further exploration of the psychological processes underlying

aggressive driving was proposed.

The research findings also suggested that aggressive on-road behaviour may

occur as a result of a wide range of on and off-road generated emotions including

excitation. Importantly, the study also suggested that for young drivers, adoption of

aggressive driving behaviour may serve several possible functions. However, more

research is required in order to confirm these findings. Due to the qualitative nature of

this study, it did not examine person-related factors in sufficient depth to reveal any

information about those drivers that are more likely to engage in the behaviour.

Therefore, there is a need to explore person-related factors in more detail in Study Two.



Chapter Five: A Quantitative Study of Aggressive Driving in Queensland

5.1 Introduction........................................................................................................... 161 5.1.1 Overview of Research Questions and Relevant Hypotheses .................. 161 5.2 Method ................................................................................................................ 166 5.2.1 Participants ............................................................................................. 166 5.2.2 Design ..................................................................................................... 167 5.2.3 Procedure ................................................................................................ 169 5.2.3.1 Scenarios .................................................................................. 170 5.2.4 Materials ................................................................................................. 171 5.2.4.1 Standardised Measures Used .................................................... 171 5.2.4.1.1 Aggression Questionnaire ..................................... 171 5.2.4.1.2 Social Problem Solving Inventory – Revised ........ 172 5.2.4.2 Research Specific Measures ..................................................... 172 5.2.4.2.1 Pre-Study Emotional State .................................... 173 5.2.4.2.2 Negative Emotional Response ............................... 173 5.2.4.2.3 Negative Attributions ............................................ 173 5.2.4.2.4 Behavioural Responses .......................................... 174 5.2.4.2.5 Post-Event Influence ............................................. 175 5.2.5 Statistical Analysis ................................................................................. 175 5.3 Results ................................................................................................................ 179 5.3.1 Data Cleaning and Testing Assumptions ............................................... 179 5.3.2 Psychometric Properties of the Standardised Measures ......................... 179 5.3.3 Factor Analysis of Research Specific Measures .................................... 180 5.3.3.1 Negative Emotions ................................................................... 180 5.3.3.2 Negative Attributions ............................................................... 181 5.3.3.3 Behavioural Responses ............................................................ 182 5.3.3.4 Post-Event Influence ................................................................ 184 5.3.4 Check of Pre-Study Emotions ................................................................ 184 5.3.5 Sample Characteristics ........................................................................... 185 5.3.5.1 Age and Gender of the Study Participants ............................... 185 5.3.5.2 Self-reported Driving Behaviour and Behavioural Intentions of the Sample ........................................................... 185 5.3.5.3 Trait Characteristics of the Sample .......................................... 188


5.3.6 Emotional, Cognitive and Behavioural Responses to On-Road Incidents .................................................................................................. 189 5.3.7 Examination of the Components Proposed in the Theoretical Framework of Aggressive Driving ......................................................... 190 5.3.7.1 Bi-variate Correlations of Variables for Consideration in the Examination of the Components of the Framework ........... 191 5.3.7.1.1 Driving Exposure and Socio-Demographic Variables ................................................................ 191 5.3.7.1.2 Negative Emotions ................................................ 192 5.3.7.1.3 Perceived Threat .................................................... 192 5.3.7.1.4 Negative Attributions ............................................ 193 5.3.7.1.5 Instrumental Behavioural Response ...................... 193 5.3.7.1.6 Hostile Aggressive Behavioural Response ............ 195 5.3.7.1.7 Post-Event Influence.............................................. 195 5.3.7.1.8 Self-Reported Measures for the Two Scenarios .... 196 5.3.7.2 Regression Analyses of Socio-Demographic, Trait and

State Person-Related Variables on Participant Emotional, Cognitive and Behavioural Responses ..................................... 197

5.3.7.2.1 Negative Emotions ................................................ 198 5.3.7.2.2 Perceived Threat .................................................... 200 5.3.7.2.3 Negative Attributions ............................................ 202 5.3.7.3 Regression of Socio-Demographic, Trait and State Person-related and Emotional and Cognitive Response Variables on Participant Behavioural Responses ..................... 205 5.3.7.3.1 Likelihood of an Instrumental Behavioural Response ................................................................ 205 5.3.7.3.2 Likelihood of a Hostile Behavioural Response ..... 208 5.3.7.4 Regression of Socio-Demographic, Trait and State Person-Related, Emotional and Cognitive Response and Behavioural Response Variables on the Likelihood of a Post-Event Influence ................................................................ 212 5.3.8 Exploratory Analyses of Potentially Hostile Aggressive Drivers .......... 215 5.3.8.1 Rationale ................................................................................... 215 5.3.8.2 PHA Driver Selection ............................................................... 215


5.3.8.3 Socio-demographic and Driving Characteristics of the PHA Drivers ............................................................................. 216 5.3.8.4 PHA Driver Differences in Trait Characteristics ..................... 217 5.3.8.5 PHA Driver Self Reported Driving Behaviour and Behavioural Intentions ............................................................. 218 5.3.8.6 PHA Driver Emotional, Cognitive and Behavioural Responses ................................................................................. 219 5.3.8.7 Ability of Variables to Predict PHA Driver Group Membership .............................................................................. 221 5.4 Discussion .................................................................................................. 222 5.4.1 Response Differences to On-Road Scenarios ......................................... 223 5.4.2 Exploration of the Components of the Proposed Theoretical Framework of Aggressive Driving ......................................................... 225 5.4.3 The Nature and Purpose of Aggressive Driving Behaviours ................. 236 5.4.4 Exploration of the PHA Driver Findings................................................ 236 5.4.4.1 Socio-Demographic and Driving Characteristics of the PHA Driver .............................................................................. 236 5.4.4.2 PHA Driver History of Driving Offences in the Previous Three Years .............................................................................. 238 5.4.4.3 PHA Driver Self-reported Driving Behaviour ......................... 238 5.4.4.4 Differences in Psychological Characteristics ........................... 239 5.4.4.5 PHA Driver Emotional, Cognitive and Behavioural Responses ................................................................................. 240 5.4.4.6 Prediction of PHA Group Membership .................................... 241 5.4.5 Implications for the Proposed Theoretical Framework of Aggressive Driving ................................................................................. 241 5.4.6 Overview of Findings and Theoretical Implications .............................. 243 5.4.7 Study Limitations ................................................................................... 244 5.4.8 Chapter Summary ................................................................................... 246



5.1 Introduction

This chapter will outline the methods, findings and implications of Study Two.

The study aimed to explore the elements of the theoretical framework for aggressive

driving based on the General Aggression Model and the findings of Study One (refer to

Figure 4.3). Consequently, this study investigated a range of psychosocial influences on

aggressive driving consistent with the key factors proposed in this framework.

The literature review and Study One findings highlighted multiple situational and

person-related factors that are believed to contribute to aggressive driving. Study One

also highlighted the role of driver perceptions in aggressive driving behaviour.

Therefore, the role of driver perceptions during an on-road incident is also explored in

this study. Further, while Study One specifically explored young driver experiences

with the phenomenon of aggressive driving, this study adopted a more general driving

population perspective, in order to examine more general age and gender differences.

The examination of a more general sample of drivers within this study, also aimed at

providing a more comprehensive understanding of the aggressive driving phenomenon

whilst endeavouring to determine the potential value of the GAM in explaining

aggressive driving.

5.1.1 Overview of Research Questions and Relevant Hypotheses

The following is an outline of the relevant research questions and hypotheses

arising from the literature review and the findings of Study One that guided the study.

More particularly, the hypotheses are informed by the theoretical framework derived

from the GAM (refer to Section 4.4.11). A rationale underpinning each hypothesis is

also provided.


driving?

H1 Drivers will report stronger emotional, cognitive, behavioural and post-

event influence in response to an intentionally anger-provoking incident

than to an ambiguous on-road incident.

The Study One findings suggest that when an on-road behaviour is perceived as

intentionally anger-provoking, a person is more likely to adopt an aggressive response.

Alternatively, aggression researchers have found that in an ambiguous situation that is


not necessarily intentional, some individuals become angered which serves to reduce the

situational ambiguity, increasing the likelihood of hostile interpretations of the situation

(Anderson, Anderson, Dill, & Deuser, 1998). Consequently, two potentially anger-

provoking scenarios, one of which was intentionally provocative in nature, are used in

the study to explore the influence of on-road situational factors on aggressive driving

outcomes. Specifically, analyses will be undertaken to examine whether drivers respond

differently when presented with a straightforward, intentional, anger-provoking situation

as opposed to an ambiguous situation.

H2 Driving exposure factors such as type of vehicle driven, exposure to

congestion and hours driven per week will be associated with driver

emotional, cognitive and behavioural responses to on-road provocation.

Study One findings suggest that aggressive drivers are more likely to drive larger

or modified vehicles. Further, high levels of on-road congestion and a greater number of

hours spent driving have also been associated with the increased likelihood of

experiencing frustration and anger whilst driving (Gordhamer et al., 1996; Hennessy &

Wiesenthal, 1997; Underwood et al., 1999). In light of this, the experience of greater

levels of perceived threat, negative emotion and associated negative attributions may

also be more likely among these drivers, increasing the likelihood of either an

instrumental or hostile aggressive behavioural response.

H3 Socio-demographic factors will be significant predictors of emotional,

cognitive and behavioural responses to on-road provocation.

Hypothesis Three is based on the literature that maintains that young, male drivers

are more likely to participate in aggressive driving behaviours (Aberg & Rimmo, 1998;

Gordhamer et al., 1996; Lajunen & Parker, 2001; VCCAV, 1999). Human aggression

and traffic researchers have reported that as age increases aggression decreases (Aberg

& Rimmo, 1998; Harris & Knight-Bohnhoff, 1996a; Lajunen & Parker, 2001). Based

on this information, young male drivers may experience greater levels of negative

emotions, perceived threat and negative attributions when faced with perceived

provocation. In turn, as suggested above higher levels of these emotions and associated

negative attributions would increase the likelihood of instrumental and hostile


aggressive behavioural responses (Berkowitz, 1993; Geen & Donnerstein, 1998;

Lajunen & Parker, 2001).

H4 Trait aggression will be a significant predictor of emotional, cognitive and

behavioural responses to on-road provocation.

Hypothesis Four is based on previous research (Lajunen & Parker, 2001) that

found drivers high on trait aggression are more likely to report a readiness to respond

aggressively to on-road provocation. Similarly, aggression theory maintains that those

individuals high on trait aggression are more likely to respond aggressively to perceived

provocation in any context (Buss & Perry, 1992; O’Connor, Archer, & Wu, 2001).

Human aggression theory maintains that the expression of aggression is more likely if an

individual experiences more negative emotion, perceived threat and negative attributions

in an anger-provoking situation (Berkowitz, 1983; Dodge & Coie, 1987; Geen &

Donnerstein, 1998; Lajunen & Parker, 2001; Shinar, 1998).

H5 Higher levels of ICS and NPO and lower levels of RPS will predict


Hypothesis Five is based on the findings that lower levels of rational problem

solving (RPS) and higher levels of the dysfunctional problem-solving styles,

impulsive/careless style (ICS) and negative problem orientation (NPO) are associated

with greater levels of expressed aggression (D’Zurilla et al., 2003). The likelihood of

aggression is further influenced by higher levels of negative emotion and negative

attributions experienced in an anger-provoking scenario (Berkowitz, 1983; Geen &

Donnerstein, 1998; Lajunen & Parker, 2001). As suggested by other researchers higher

levels of these negative problem-solving styles increase the likelihood of experiencing

intense negative emotions and negative attributions in the face of a perceived

provocation (Elliott, Herrick, MacNair, & Harkins, 1994; Yagil, 2001).

H6 Pre-study emotions, as a measure of state person-related stress, will

influence emotional, cognitive and behavioural responses to on-road

provocation.

This hypothesis is centred around the potential for off-road generated stress to

influence on-road behaviours (Navaco et al., 1990; Simon & Corbett, 1996; Smith,

1970). Study One findings also suggested that off-road stress caused by work or


relationship difficulties has the potential to negatively impact upon driving behaviour.

Therefore, for the purpose of this study, state person-related stress was assessed in

terms of ‘pre-study emotions’ immediately prior to completing the questionnaire (see

Section 5.2.4.2.1).


driving behaviour?

H7 Higher levels of negative emotion, perceived threat and negative

attributions will predict the likelihood of stronger instrumental and hostile

aggressive behavioural responses to on-road provocation.

H8 Higher levels of negative emotion, perceived threat, negative attributions

and an increased reporting of a behavioural response to on-road

provocation will increase the likelihood of a post-event influence being

experienced.

Hypotheses Seven and Eight are based on the premise that higher levels of

negative emotions, perceived threat and negative attributions experienced in an on-road

situation will increase the likelihood of an aggressive behavioural response that may

continue to influence the driver after the on-road event has passed (i.e. ‘post-event’)

(Anderson & Bushman, 2002). Additionally, human aggression research has found that

individuals who are provoked have a greater likelihood of responding aggressively in

response to a subsequent trivial trigger, than those individuals who were not initially

provoked (Pedersen et al., 2000). Traffic researchers also maintain that on-road

provocation increases the experience of on-road stress that may, in turn, influence

behavioural responses to subsequent on-road interactions (Navaco et al., 1990;

Parkinson, 2001). Navaco and colleagues (1990) also maintain that the experience of

this stress may transfer into the work or home environment. The Study One findings

also indicated that thirteen young drivers continued to experience negative emotion for

some time after an on-road incident (Sections 4.3.4.4 and 4.3.5.8).



behaviours? and RQ4 What function does aggressive driving perform for

drivers?

H9 The response of drivers to an intentionally provocative on-road incident

can be categorised into two distinct but related types of behaviours,

instrumental or hostile, which serve different functions for drivers.

Section 2.6 outlined the rationale for RQ3. In this discussion, there appeared to be

some support for aggressive driving behaviour forming a ‘continuum’ of less severe to

more severe on-road behaviours. This idea is indirectly supported by evidence

indicating that lesser acts of on-road aggression can sometimes lead to an escalation of

an on-road event, and in turn, to physical violence. However, Shinar (1998) proposed a

dichotomous classification of on-road aggressive behaviours as either instrumental or

hostile. He elaborated upon these two types of on-road behaviour, suggesting that both

types serve different functions for road users (Shinar, 1998).

RQ6 Are there differences in the characteristics of those drivers who are prepared to

engage in hostile acts of aggressive driving compared to those who only report

engaging in instrumental acts of aggressive driving?

Chapter Three literature review findings and Study One findings highlighted a

number of potentially important socio-demographic, psychological and person-related

factors that increase the likelihood of aggressive driving behaviour. Considering these

results, this study will also explore possible differences that can be found between

general road users and those drivers identified as potentially hostile aggressive (PHA)

who are prepared to engage in relatively severe acts of aggressive driving.

Due to the exploratory nature of this investigation into these PHA drivers,

specific hypotheses were not proposed. However, particular issues were examined,

including the extent to which PHA drivers differed from other drivers in terms of their:

• socio-demographic characteristics and general driving behaviour;

• trait aggression and problem-solving ability;

• self-reported crash and offence involvement; and


• emotional, cognitive and behavioural responses to provocative on-road

incidents.

The literature review reports that male drivers are more likely to participate in

aggressive driving behaviours (DCPC, 2005; Harding et al., 1998; VCCAV, 1990;

Lajunen & Parker, 2001; Shinar, 1998). The literature review also suggests that more

aggressive individuals are more likely to have had less formal education (Harris &

Knight-Bohnhoff, 1996; Shinar et al., 2001), drive more hours per week and more

frequently encounter higher levels of traffic congestion (Hennessy & Wiesenthal, 2001;

Underwood et al., 1999). Study One findings also suggested that aggressive drivers may

drive larger vehicles.

PHA drivers as potentially more aggressive individuals may have a significantly

greater history of on-road risk-taking behaviours in the past three years. Specifically, it

is anticipated that they will have had higher levels of crash involvement, more speeding

fines, drink-driving and unlicensed driving charges than other drivers. Similarly, it is

anticipated that PHA drivers may report a greater willingness to engage in on-road risk-

taking behaviours. Specifically, they may be more likely to exceed the limit by 10km/h

or more on urban roads and highways than other drivers. They may also be more likely

to indicate a willingness to drink/drug drive than other drivers. The literature review

findings suggest that trait aggression and problem-solving styles were found to be

associated with emotional, cognitive and behavioural response characteristics.

Therefore, it is possible that PHA drivers will differ from other drivers on these trait

person-related characteristics.

Finally, the literature reviewed in Chapter Three suggests that more intense

emotions, higher levels of threat and the greater likelihood of negative attributions are

associated with the increased likelihood of aggressive behaviours. Therefore, it is

possible that those drivers identified as PHA will have a greater emotional, cognitive

and behavioural response to both scenarios one and two than other drivers.

5.2 Method

5.2.1 Participants

Two participant pools were utilised for this research: 5,000 current members of

the Royal Automobile Club of Queensland (RACQ) and students of the Queensland


University of Technology (QUT). The final sample consisted of 853 RACQ members

(350 male and 503 female) and 73 QUT first-year psychology students (12 male and 61

female). The only selection criteria applied was that participants needed to hold a

current driver’s licence.

Use of the RACQ membership pool allowed researchers to target a wide age

range of Queensland drivers. A stratified random sample was drawn from the RACQ

database consisting of equal numbers of male and female drivers aged under 25 years,

25–44 years, 45–64 years and 65 years and older (refer to Appendix E for more details

of the RACQ sample). In an effort to obtain a representative cross-section of the

Queensland driving population a range of areas was targeted, with those contacted being

drawn from Brisbane, Ipswich and surrounding geographic areas, the Gold Coast, South

West Queensland, Central Queensland, the Wide Bay area, North Queensland and Far

North Queensland (see Appendix E).

Considering the traditional over-representation of young drivers in aggressive

driving research and a possibility that younger RACQ members may be less likely to

participate in the survey, QUT students were also approached in order to ensure that

sufficient numbers of younger drivers were involved in the research. QUT participants

were recruited from the first-year psychology participant pool.

5.2.2 Design

For the purposes of Study Two, the adoption of a research design which involved

the provocation of participants in either a simulated or actual driving environment

presented several ethical and professional problems, as found in earlier human

aggression research (Baron, 1977). Additionally, observational methods were also

considered, however, it was considered that such methods would be inappropriate for the

exploration of the underlying emotional and cognitive processes involved in aggressive

driving behaviour. Alternatively, many traffic researchers have relied upon self-report,

diary or questionnaire methods to investigate the phenomenon of aggressive driving.

Adoption of such methodological approaches has raised questions concerning the

truthfulness of participant responses, particularly in terms of behavioural response, as

some participants may wish to present themselves in a socially desirable manner (Baron,

1977). However, the careful design and manipulation of the variables of interest (Baron,


1977, p. 42) may minimise the potentially negative effect of this phenomenon.

Therefore, given the inevitable practical and ethical problems with conducting on-road

studies, it was decided to use self-report measures in Study Two and to manipulate the

emotional, cognitive and behavioural response variables of interest using scenarios.

A self-report questionnaire was designed to examine the theoretical framework

of aggressive driving described in Section 4.4.11. Appendix F contains a copy of the

Study Two questionnaire. The cover page varied depending on the targeted participant

pool (Appendices G and H).

The first part of the questionnaire was designed to collect a range of socio-

demographic and driving behaviour information. This included age, gender, education

attained and various driving exposure variables, including the likelihood of engaging in

speeding and/or drink/drug driving behaviour (Appendix F). The second part of the

questionnaire contained standardised measures in order to ascertain participant scores on

trait characteristics (Appendix F). As such, participants were asked to complete the

Aggression Questionnaire (AQ) and three subscales of the Social Problem Solving

Inventory – Revised (SPSI-R). Details of these standardised measures are provided in

Section 5.2.4.1.

The questionnaire was also designed to explore the emotional state of

participants prior to their participation. In particular, self-reported levels of stress,

agitation and positive affect were assessed (Appendix F). This check was considered

necessary due to the potential influence of emotional state on participant emotional and

behavioural responses to a potentially anger-provoking scenario, as suggested by

previous research and the GAM (‘present internal state’) (Anderson & Bushman, 2002;

Berkowitz, 1983; Carver, Sheier, & Weintraub, 1989; Hennessy & Wiesenthal, 2001;

Knight, Guthrie, Page, & Fabes, 2002; Lajunen & Parker, 2001). Prior to the conduct

of the analyses, the variables were sorted into broader subject categories consistent with

the psychological components of the GAM (see Table 5.1).


Table 5.1: Breakdown of individual variables into broader subject categories

Broad Subject Categories

Variables

Socio-Demographic

Age Gender Driving Exposure Variables

Trait Person-Related Characteristics

AQ Scores SPSI-R Subscales – NPO, ICS and RPS

State Person-Related Characteristics Pre-Study Emotions

Emotional and Cognitive Responses

Negative Emotional Response Threat Response Negative Cognitive Response


Instrumental Aggressive Behavioural Response Potentially Hostile Aggressive Behavioural Response

Post-Event

Post-Event Influence

The remainder of the questionnaire was designed to measure participant

emotional, cognitive and behavioural responses to two particular driving scenarios (see

Section 5.2.3.2 and Appendix F). In order to facilitate analyses, an average total score

for the emotional, cognitive, behavioural responses and post-event influence variables

was calculated for each participant in response to both Scenarios One and Two.

Specifically, their average total scores were computed for negative emotion, negative

cognition, likelihood of an instrumental aggressive response, likelihood of a hostile

aggressive response and potential post-event influence for each scenario.

5.2.3 Procedure

RACQ members were randomly selected and approached via mail to participate

in the study. The members were mailed the questionnaire directly by the RACQ, to

ensure their privacy. Completion of the questionnaire took approximately 20 minutes,

although no time limit was applied. Completed questionnaires were returned directly to

QUT by post. Completion and return of the questionnaire by RACQ participants was

deemed as their consent to participate. All RACQ members that chose to participate


were given the opportunity to enter into a competition for a free, one year RACQ

membership.

Of the 5,000 questionnaires distributed to RACQ members, 878 drivers returned

the questionnaire representing an 18% response rate. Upon examination, 25 of these

were missing substantial data and were therefore not used in the research.

Prior to completing the questionnaire the QUT participants were asked to read

the information package attached to the front of the document and sign the sheet

indicating their consent to participate (see Appendix H). These participants completed

their questionnaire on campus. Upon completion of the questionnaire, these participants

were granted credit towards the completion of their first year Psychology Program. Of

74 questionnaires obtained from QUT, only one questionnaire was unable to be used in

the study.

5.2.3.1 Scenarios

Two differing scenarios were presented to participants in the study questionnaire

in order to explore their likely responses to potentially provocative on-road incidents.

Specifically, the intentionality of the ‘other driver’ behaviour was manipulated in each

scenario. Scenario One was designed to present a clearly provocative on-road incident

which portrayed the ‘other driver’ behaviour as intentional:

“You are driving down a two lane road (one lane each way) travelling at the

speed limit and you notice that the car behind you is travelling very close to your

vehicle. Instead of waiting for an opportunity to overtake you, the driver

proceeds to flash his/her lights and beep his/her horn.”

In contrast, Scenario Two was designed to be more ambiguous, though

potentially anger-provoking. In this scenario, the intentionality of ‘other driver’

behaviour was intended to be unclear in nature.

“You have just had an argument with someone close to you, prior to getting in

the car. You then approach an intersection and the light changes to ‘red’. You

come to a stop behind another car. The light seems to take a long time to change

back to ‘green’. When the light finally changes the driver in front does not move

off, preventing you from moving forward.”


The dependent variables used to assess responses to each scenario were: negative

emotional response; perceived threat; likelihood of negative attributions; likelihood of

an instrumental and/or hostile behavioural response; duration of post event emotion; and

likelihood of a post-event influence.

The two scenarios were piloted prior to the finalisation of the questionnaire.

This process confirmed that Scenario One tended to be perceived as an intentional,

anger-provoking act, irrespective of the emotional state of the driver being tailgated.

However, the piloting did highlight differences in the interpretation of Scenario Two,

which prompted the inclusion of a pre-existing emotional state in the scenario (i.e. “You

have just had an argument with someone close to you, prior to getting in the car”) for

two reasons. Firstly, the participants in the pilot phase reported that, due to the

ambiguity of the situation, their response would likely vary based on how they were

feeling at that particular point in time. Secondly, some pilot participants indicated that

they would not necessarily experience anger in this situation, unless they were already in

a somewhat heightened emotional state. Hence the inclusion of a pre-existing emotional

state in the second scenario was designed to both ‘standardise’ the influence of this

factor across the participants and to ensure that a threshold level of anger was achieved

for at least some participants. However, it is recognised that the inclusion of the pre-

existing emotional state in Scenario Two introduced a factor not specifically addressed

in Scenario One. The implications of this are further discussed in the Study Limitations

Section (refer to Section 5.4.7).

5.2.4 Materials

5.2.4.1 Standardised Measures Used

5.2.4.1.1 Aggression Questionnaire. All four subscales of the AQ were

administered to participants: the physical and verbal aggression subscales, the general

anger scale and the hostility subscale (Buss & Perry, 1992). The overall reliability of the

full 29 items of the AQ has previously been estimated at Cronbach’s α = .92, in a sample

of 19–55 year old males (O’Connor, Archer, & Wu, 2001). Thus the overall measure of

trait aggression consisted of 29 items (refer to Appendix F). Participants rated how

characteristic the items were of themselves on a 5 point Likert Scale (1 = ‘extremely

characteristic of me’, 5 = ‘extremely uncharacteristic of me’).


For the purpose of this study a composite score measuring trait aggression was

constructed for each participant in order to conduct further analysis. Items 7 and 19

were reverse scored.

5.2.4.1.2 Social Problem Solving Inventory – Revised. The SPSI-R is designed

to measure an individual’s general ability to solve problems, without emphasising

specific situations. Specifically, the measure assesses two constructive/adaptive

dimensions and three dysfunctional dimensions of problem solving. Five subscales are

used to measure these dimensions: positive problem orientation (PPO) and rational

problem solving (RPS) versus negative problem orientation (NPO),

impulsivity/carelessness (ICS) and avoidance style (ACS). These subscales focus on

two primary distinctions made in problem-solving research: positive versus negative

problem orientation. Problem orientation encompasses the ways in which problems and

events are perceived and interpreted by an individual. In two separate studies focusing

on the problem- solving styles of young adults (n = 1053) and middle-aged adults (n =

100) respectively, researchers have reported sound reliability estimates for the three

subscales used in this study: NPO (α = .83, n = 1053; α = .80, n = 100); ICS (α = .74,

n = 1053; α = .78, n = 100); and RPS (α = .78, n = 1053; α = .88, n = 100) (Kant,

D’Zurilla, & Maydeu-Olivares, 1997).

The SPSI-R requires that participants indicate how characteristic the items are of

themselves on a five point Likert Scale (1 = ‘not at all true of me’ to 5 = ‘extremely true

of me’). For the purpose of this study only three of the SPSI-R subscales were used, as

they have been found in previous research to have strong associations with aggression

(Kant et al., 1997): NPO, ICS and RPS (refer to Appendix F). Consequently, calculation

of a composite ‘problem solving’ score would not be appropriate or overly meaningful

as only three of the original five subscales were used.

5.2.4.2 Research Specific Measures

The following is a brief outline of the measures that were developed by the

researcher to assess the applicability of the components identified in the theoretical

framework of aggressive driving first proposed at Figure 4.3. Also included is a brief

outline of the logic behind their development. The internal reliability of each measure

will be dealt with in Section 5.3.3, in conjunction with the factor analyses.


5.2.4.2.1 Pre-Study Emotional State. Previous research suggests that the

emotional or stressful state that a driver brings to the on-road environment has the

potential to increase the likelihood of aggressive behaviour and driving errors (Aseltine

et al., 2000; Deffenbacher et al., 2000; Gulian et al., 1989; Hartley & Hassani, 1994;

Hennessy & Wiesenthal, 1999; Navaco et al., 1990). In an attempt to measure the

emotive or stressful state which participants brought to the study (and hence the

scenarios), they were asked to indicate on a five point Likert scale whether they were 1=

‘very happy’ to 5 = ‘very unhappy’; 1 = ‘very calm’ to 5 = ‘very agitated’; and 1= ‘not

stressed at all’ to 5 = ‘very stressed’ at the time of completing the questionnaire.

For each participant, an average of the three items was calculated to provide a

measure of pre-study emotions. Higher scores reflected higher self-reported levels of

stress, unhappiness or agitation prior to completing the questionnaire.

5.2.4.2.2 Negative Emotional Response. As identified in the literature review, it

has been proposed that there are three key components to an aggressive response: an

emotional response, a cognitive response, and a behavioural response. In order to

measure the emotional response of participants to the on-road incidents portrayed in the

scenarios, participants were asked to indicate the degree to which they would feel angry,

annoyed, agitated and/or threatened on a 1-5 Likert scale (1 = ‘not at all’ to 5 = ‘very

much’).

5.2.4.2.3 Negative Attributions. The second component of an aggressive

behavioural response is cognition. Cognitions associated with the adoption of

aggressive driving behaviour are often negative and personal (i.e. negative attributions).

Consistent with Yagil’s (2001) research into negative attributions and aggressive driving

behaviour, the thoughts reflected in this measure are classed as ‘negative attributions’.

Participants were asked to nominate the likelihood of their having three negative

thoughts about the ‘offending driver’ in response to each scenario (Table 5.2). These

items called for a response on a 1-5 Likert scale (1 = ‘extremely unlikely’ to 5 =

‘extremely likely’).


Table 5.2: Items in the negative attribution scale

Items

a) What an idiot!

b) How did that fool get his licence!

c) That idiot shouldn’t be allowed on the road!

5.2.4.2.4. Behavioural Responses. The set of behaviours reported in Table 5.3 were used to assess the participants’ reported response to the two scenarios. This behavioural response set was derived from prior aggressive driving research (refer to Section 2.2). In response to each scenario, participants were asked to indicate the likelihood of engaging in each of the behavioural responses. Participants were asked to indicate on a 1-5 Likert scale (1 = ‘extremely unlikely’ to 5 = ‘extremely likely’) the likelihood of their responding to the scenario in the manner indicated. Items three and seven gave participants the option of not having a behavioural response, as it is not axiomatic that all drivers will respond to on-road provocation with a form of reactive aggression. Consequently, as this research focuses on the expression of potentially aggressive responses on the road, both items were not specifically considered in the majority of the subsequent analyses.

Table 5.3: Questionnaire behavioural response set

Behavioural Response Set

1. Swear or mutter to yourself or others in your car.

2. Give a blast of your horn and/or flash lights.

3. Carry on driving normally.*

4. Gesture at the other driver.

5. Swear at and/or verbally abuse the other driver.

6. Drive close to/follow the other vehicle.

7. Ignore the driver/incident as if nothing has happened.*

8. Stop the vehicle and get out of your vehicle, ready to argue. 9. Stop the vehicle and get out prepared to engage physically with the other driver.

10. Shout or scream out loud but not at the offending driver.

11. Use your vehicle to physically damage the other driver’s vehicle. * Items 3 and 7 were not included in the factor analysis of aggressive behavioural outcomes


5.2.4.2.5 Post-Event Influence. Table 5.5 outlines the potential post-event

experiences used to construct this measure. For each item, participants were asked to

indicate the likelihood of the on-road incident influencing their subsequent behaviours

on a 1-5 Likert scale (1 = ‘not at all likely’ to 5 = ‘extremely likely’).

Table 5.4 Items in post-event experiences

Items

a) During the rest of your trip. b) Doing other tasks during the day. c) In your dealings with others.

5.2.5 Statistical Analysis

A series of regression analyses were used to examine the psychological components of

the GAM (Anderson & Bushman, 2002) that have been found relevant to aggressive

driving behaviour. This statistical approach was considered appropriate for exploring the

relationships between the various stages of the GAM based model of aggressive driving.

Figure 5.1 below depicts the staged exploration of the theoretical framework of aggressive

driving derived from the findings of Study One and the literature review (see Section

4.4.11). As can be seen, stage one analyses examined the relationships between driver

socio-demographic, trait and state related characteristics and their reported levels of

negative emotions, feelings of threat and the likelihood of them adopting negative

attributions in response to each of the on-road scenarios. Notably, Figure 5.1 does not

include reference to the participants’ ‘present internal state’, encapsulated in the full GAM

(see Figure 4.3). This component of the model was not operationalised in this study due to

the inherent limitations of self-report, scenario-based studies. In particular, it would have

been highly artificial to require the participants to reflect on their likely ‘internal present

state’ in response to the scenarios. Rather, it was decided to focus on the emotional and

cognitive responses of the participants to the scenarios provided (as an indicator of their

‘present internal state’), which was referred to as their ‘emotional and cognitive response’.


Nonetheless, the decision not to operationalise the ‘present internal state’ component of

the GAM is a limitation which needs to be borne in mind and is further discussed in

Section 5.4.7.

The stage two analyses examined the relationships between the drivers’ emotional and

cognitive responses and the likelihood of them adopting either an instrumental and/or

hostile behavioural response. The final, third stage examined the relationship between the

likelihood of behavioural response and a post-event influence.

Structural Equation Modelling (SEM) was not utilised as the aim of the study was not

to establish the structural integrity of the model itself, but rather to explore the

relationships between the various components in the framework. Furthermore, due to the

specific requirements of SEM, it would have been necessary to include additional

subscale items in the questionnaire which would have increased its length and possibly

reduced the overall response rate. Accordingly, it was considered that SEM would be a

more appropriate analytical method in future research, once the various components

within the framework had been explored and established.

Prior to conducting the multiple regression analyses, the following ratio of cases to

independent variable calculation was assessed: N ≥ 50 + 8m (m is the number of IVs)

(Tabachnik & Fidell, 1996, p.132). All regression analyses met this criteria. Many of the

variables that were measured by Likert scales, although not strictly representing interval

data, were treated as continuous variables to facilitate the use of parametric statistics.

This restrictive assumption should be borne in mind when interpreting the results. In

addition, the categorical age variable was recoded by utilising the mid-point of each of the

age categories, enabling it to be treated as a continuous variable in the multiple regression

analyses. Similarly, the education level variable was recoded into a dichotomous variable

to facilitate its inclusion in the multiple regression analyses.

In consideration of the order of entry of the variables into the analyses, the logic of

the research, causal priority, research structure and attempts to minimise spurious

relationships were examined (Cohen, Cohen, West, & Aiken, 2003). This choice of

cumulative sequencing of IVs was also made in advance and determined primarily by

structural properties of the GAM model (Anderson & Bushman, 2002). Notably, the

GAM sequence reflects relevant temporal considerations.


Figure 5.1 Diagrammatic presentation of the three stage exploration of theoretical

components

For example, one brings their socio-demographic, state and trait characteristics to the

on-road environment on each occasion. Subsequently, exposure to a potentially anger-

provoking scenario may result in an emotional and cognitive response, and in turn a

behavioural response. Therefore, the adoption of this three-tiered regression strategy

and subsequent entry of variables into the equation in ‘blocks’, was the preferred

analytic approach (refer to Figure 5.1). However, it is recognised that the use of

hierarchical regression inevitably gives more precedence to those variables entered

earlier in the model. As such, this is a limitation that needs to be borne in mind when

interpreting the results (see Section 5.4.7).

Stages of Analysis ___ Stage One - - - Stage Two ….. Stage Three

Socio-demographic

Characteristics (Age, gender, educational

attained, driving exposure variables)

State Person-related

Characteristics (Pre-study Emotions)

Emotional &

Cognitive Response

Negative Emotions

Threat

Negative

Attributions

Likelihood of

Behavioural Response

Instrumental

Hostile

Post-event Influence

Trait Person-related

Characteristics (Total AQ, SPSI-R

subscales)


The general significance level for the analyses adopted was α = .05. Where

necessary Bonferroni adjustments were made to control for Type I error. In addition,

given that a number of regression analyses were conducted a more conservative

significance level of α < .001 was chosen for these analyses to guard against

experiment-wise error. However, significant results at α < .01 and α < .05 are also

noted. Only significant correlation coefficients of .2 and above are generally reported.

For the exploratory analyses involving the potentially hostile aggressive (PHA)

drivers (Section 5.3.8), non-parametric tests were considered necessary to account for

the problematic skewness and kurtosis associated with a number of the variables

(Tabachnick & Fidell, 1996). As a consequence, in an effort to determine where, if any,

differences exist between the PHA drivers (n = 88) and other drivers (n = 838) a series

of non-parametric tests were conducted comparing the two groups on the measured

variables.

In order to examine any differences between the PHA driver group and other

drivers on categorical data using Chi Square techniques, many of the variables needed to

be collapsed as some of the obtained cell frequencies were less than 5, contrary to what

is required for use of this statistical technique (Cohen et al., 1996). In these analyses,

when overall significance was found, post hoc analyses were undertaken within each

variable using the adjusted standardised residual (i.e. ê). This statistic assists in

identifying cells with observed frequencies significantly higher or lower than expected.

The adjusted standardised residuals can be interpreted as Z-scores (Haberman, 1978).

The strength of association between the categorical variables was assessed using the Phi

co-efficient (ø) for tables 2 x 2 or Cramer’s V (øc) for tables with more than 2 x 2 (Aron

& Aron, 1999).

For the purpose of the logistic regression analysis of the PHA driver group the

age variable was dummy coded and collapsed into four categories: 17–24 years; 25–39

years; 40–59 years and 60 years and over. The 17–24 year age group was used as the

reference group in this analysis. This approach was adopted as opposed to the recoding

used for the multiple regression analyses, to allow direct comparison of the different age

categories. As before, the categorical variable ‘education’ was collapsed to create a

dichotomous variable, i.e. 0 = ‘less than year 10 education’ and 1 = ‘greater than a year


10 education’. Three other discrete variables concerning ‘driving exposure’ were

collapsed and dummy coded to enable the regression analyses (type of vehicle, level of

traffic congestion most frequently exposed to, and hours driven per week). Details of

the resultant changes are outlined in the relevant tables of each analysis.

5.3 Results

5.3.1 Data Cleaning and Testing Assumptions

Data cleaning was applied to all independent and composite variables.

Participant questionnaires with missing data for four or more items, were visually

examined. Those participants with missing values that represented a pattern, or

sufficient missing data in any one of the measures to render a whole measure unusable,

were deleted from the data set. Other missing items were replaced with the mean

response for that item.

Examination of Levene’s test of homogeneity of variance, assessed at p < .05 has

been considered extremely strict (Tabachnik & Fidell, 1996), therefore, the probability

for a significant breach was reduced to p < .001. Despite this, several variables appear

to have breached Levene’s test of homogeneity of variance.

In testing the assumptions prior to the conduct of regression analyses, the

multivariate data cleaning entailed examination of ‘z’ scores, Mahalanobis distances and

scatter plots for all variables. Inspection of frequencies and normal probability plots for

all variables including composites revealed a number of univariate outliers and some

skewness. Those variables that were somewhat affected were: trait aggression (AQ

scores), ICS and NPO problem-solving styles, negative emotions, and instrumental and

hostile behavioural response variables. However, by the very nature of this study and its

examination of aggression, it was anticipated that there would be a number of

participants whose responses would gravitate towards the extreme end of scores. As a

result, it was decided to retain the outliers.

5.3.2 Psychometric Properties of the Standardised Measures

The overall means and standard deviations of trait aggression as measured by the

AQ (Buss & Perry, 1992) and coping style as measured by the three SPSI-R subscales

are presented below (Table 5.5).

The internal reliability of the three SPSI-R subscales used in this study was


evaluated separately using Cronbach’s alpha: NPO (.84), ICS (.76), and RPS (.82) (refer

to Appendix I). The internal reliability of the full 29 items of the AQ was evaluated at

Cronbach’s alpha .90 (refer to Appendix I). Therefore, the internal reliability of the

three problem solving subscales and the AQ was considered sufficient.

Table 5.5: Means and standard deviations of trait characteristics (n=926)

Variable

M

SD

Total AQ Score

46.96

15.57

Negative Problem Solving

5.21

.52

Impulsive/Careless Style

5.16

.54

Rational Problem Solving

3.32

.87

5.3.3 Factor Analysis of Research Specific Measures

Factor analyses were conducted to investigate the dimensionality of the measures

used in this study. For each measure, separate factor analyses were conducted on

participant responses to each scenario (i.e. Scenarios One and Two). As the research

specific measures used were exploratory in nature i.e. they were designed for this

survey, it was pre-determined that a reasonably high factor loading should be used.

Therefore, only items loading >.5 were retained. The internal reliability for each of the

following scales can be found at Appendix I.

5.3.3.1 Negative Emotions

The dimensionality of the four items detailed at Section 5.2.4.2 was subjected to

principal axis factoring in order to determine their measurement of one or more factors.

The analysis of the responses to Scenario One revealed one factor with an eigenvalue >

1 (eigenvalue = 2.105), explaining 56% of the variance in this factor. Inspection of the

scree plot also supported the existence of one factor. Consequently, principal axis

factoring, using oblimin rotation, excluding items loading <.5, revealed the item

loadings on the factor presented at Table 5.6. All items except ‘threat’ loaded well on

one factor. Similar results were obtained for Scenario Two. Consequently, the threat


item was excluded from the scale. The three item factor was subsequently named

‘negative emotional response’. The internal reliability of the three item factor in

response to Scenario One was evaluated at Cronbach’s α = .79. This analysis was

repeated for participant responses to Scenario Two and the analysis were almost

identical, revealing one factor (eigenvalue = 2.3) explaining 65% of the variance, with a

Cronbach’s of α = .85 (refer to Table 5.6) (see Appendix I).

Table 5.6 Factor loadings for negative emotional response for Scenarios One and Two

Items

Scenario One Factor Loading

Scenario Two Factor Loading

Angry

Annoyed

Agitated

.853

.707

.674

.831

.786

.801

Cronbach’s α .79 .85

5.3.3.2 Negative Attributions

Principal axis factoring was used to determine the dimensionality of the three items

in this measure. Consistent with the scree plot, the analysis for Scenario One revealed

one factor with an eigenvalue = 2.181, explaining 62% of the variance explained by the

factor (Table 5.7). The internal reliability of the three item factor was Cronbach’s α =

.81 (Appendix I).

Table 5.7 Factor loadings for negative attribution factor for Scenarios One and Two

Items Scenario One Factor One

Loading

Scenario Two Factor One

Loading a) What an idiot! .898 .919

b) How did that fool get his licence! .880 .918

c) That idiot shouldn’t be allowed on the road!

.541 .623


The exploratory factor analysis procedure was repeated with participant responses

to Scenario Two, yielding comparable results. Again, the principal axis factoring


revealed one factor (eigenvalue = 2.334) explaining 69% of the variance in this factor,

Cronbach’s α = .84.

It should be noted, however, that deletion of the first item ‘What an idiot!’,

resulted in a higher reliability estimate in response to Scenario One and Scenario Two (α

= .88 and α = .91 respectively). However, this item was retained in the calculation of

average scores of negative cognition in response to Scenarios One and Two, since the

original Cronbach’s α’s were considered adequate.

5.3.3.3 Behavioural Responses

The factor analysis of the behavioural measure, designed specifically for this

study, not only examined the structure of the measure, but was also relevant to the

following hypotheses:

H9 The response of drivers to a provocative on-road incident can be

categorised into two types of behaviours, instrumental or hostile. These

types of behaviours will serve different functions for drivers.

The nine reactive aggressive behaviours detailed in Section 5.2.4.2 were used in

the following factor analyses (refer to Table 5.8). As previously noted, items three and

seven did not involve the adoption of a potentially aggressive behavioural response and

were thus excluded from the factor analysis procedure.

Examination of the resultant scree plot in conjunction with principal components

analysis, revealed two factors with an eigenvalue > 1, explaining 59% of the variance in

these two factors (Factor One, eigenvalue = 3.612 and Factor Two, eigenvalue = 1.684).

The overall internal reliability of this measure using Cronbach’s alpha was .77 (see

Appendix I). The individual reliability estimates for Factors One and Two were α = .76

and α = .85 respectively.

In addition, the exploratory factor analysis procedure was repeated with

participant behavioural response to Scenario Two. Again, examination of the scree plot

and eigenvalues revealed two factors (factor one, eigenvalue=3.498 and factor two,

eigenvalue=1.802) explaining 59% of the variance. The overall Cronbach’s α was .74.

Having considered differences in the items and their loadings, the behaviours

appeared to group into two distinct concepts. Factor One appeared to involve lesser acts

of reactive aggression, representing behaviours consistent with Shinar’s preposed


construct of ‘instrumental’ aggression. In other words, these behaviours may be adopted

in order to release aggression or remove the source of on-road frustration in order to

continue on one’s journey. Conversely, Factor Two clearly involved extreme forms of

reactive aggression with the potential to involve interpersonal violence and also a

preparedness to put immediate goals aside. Consistent with Shinar’s model (1998), this

factor was labelled ‘hostile aggression’.

Contrary to expectations, item 6 – ‘drive close to/follow the other vehicle’ loaded

onto Factor One in response to both scenarios (see Table 5.8). Although, the

consequences of such behaviour may increase the likelihood of an on-road incident

escalating to a more serious altercation, the results suggest that the participants did not

consider this behaviour to be extreme, or hostile, in isolation.

Table 5.8 Factor loadings of behavioural response set for Scenarios One and Two

Questionnaire Item Scenario One

α = .77 Scenario Two

α = .74

Factor One

Factor Two

Factor

One

Factor

Two

5. Swear at and/or verbally abuse the other driver. .791 .763

4. Gesture at the other driver. .811 .792

2. Give a blast of your horn and/or flash lights. .697

.683

10. Shout or scream out loud but not at the offending driver.

.536 .566

1. Swear or mutter to yourself or others in your car. .613

.655

6. Drive close to/follow the other vehicle. .484 .497

9. Stop the vehicle and get out prepared to engage physically with the other driver.

.918 .923

8. Stop the vehicle and get out of your vehicle, ready to argue.

.827 .765

11. Use your vehicle to physically damage the other driver’s vehicle.

.840 .853

Cronbach’s α .76

.85

.74

.83

Examination of the correlation between the average total instrumental and

hostile aggression scores of participants for each scenario indicated that the two types of

behaviour have a significant but moderate association (Scenario One, r = .37, p < .001;


Scenario Two, r = .28, p < .001). Therefore, whilst it appears that instrumental and

hostile on-road aggressive behaviours fall into two distinct groups, they do appear to be

related constructs. The relevant items for each construct were subsequently computed to

produce an average ‘instrumental behavioural response’ and an average ‘hostile

behavioural response’ scores for each participant, in response to each scenario.

5.3.3.4 Post-Event Influence

Using Scenario One data, principal components analysis produced evidence of

one factor, eigenvalue = 2.295, explaining 77% of the variance in this factor. Table 5.9

details the factor loadings for the three relevant items. The internal reliability of the

measure was Cronbach’s α = .82.

Table 5.9 Factor loadings of items onto likelihood of post-event influence for Scenarios

One and Two

Items

Scenario One Factor One

Scenario Two Factor One

a. During the rest of your trip. .806 .816

b. Doing other tasks during the day. .934 .931

c. In your dealings with others. .880 .915


Again, the analysis was applied to participant responses for Scenario Two. The

analysis also produced one factor with an eigenvalue = 2.370, producing highly

comparable results with a Cronbach’s α = .85. The three items were, therefore, used to

calculate an average ‘likelihood of a post-event influence’ score for each participant in

response to each of the scenarios.

5.3.4 Check of Pre-Study Emotions

A 2 x4 ANOVA evaluating age group (four levels) by gender (two) effects on

self-reported emotionality at the time of completing the questionnaire was significant, F

(7,918) = 14.652, p < .001, η2 = .10. However, only a simple main effect (SME) was

found between the age groups, F (3,918) = 28.496, p < .001, η2 = .09. No SME was

found for gender F (1,918) = .166, p = .577. Nor was there a significant interaction

between age and gender F (3,918) = .710, p = .546.


Post hoc comparisons of the age groups found that 17–24 year olds reported

significantly greater levels of pre-study negative emotion than all other drivers, p < .05.

However, there was no significant difference between the 25–39 year old age group and

40–59 year olds, p > .05. Older participants aged 60 years plus reported significantly

less pre-study negative emotion than the other age groups, p < .05. As such, the results

suggest that the pre-study emotions need to be included in the regression analyses to

control for their potential influence on the other factors measured in the research.

5.3.5 Sample Characteristics

5.3.5.1 Age and Gender of the Study Participants

Table 5.10 outlines participant gender by age groups within both participant

pools. The age groups were created to facilitate the analyses and were based on

categories commonly used in road safety research.

Table 5.10 Age and gender of the participants by source

Participant Pool Age Groups Sex n

Female Male

RACQ 17–24 years 186 97

25–39 101 39

40–59 123 104

60 years plus 93 110

Subtotal 503 350 853

QUT 17–24 40 9

25–39 15 2

40–59 5 1

60 years plus 1 nil

Subtotal 61 12 73

TOTAL 564 362 926

5.3.5.2 Self-reported Driving Behaviour and Behavioural Intentions of the Sample

Table 5.11 provides an overview of the findings related to the driving behaviour

characteristics and the behavioural intentions of the sample. As can be seen in the tables

at Appendix J, due to the overrepresentation of young drivers in on-road aggression,

special attention needs to be given to those drivers aged 17–24 years of age in the


sample. Full details of the chi-square analyses associated with the significant results

relating to driving behaviours are included at Appendix J.

The majority of participants (n = 797) reported that they drove mainly on city/town

roads, while 694 participants indicated that they drove more frequently in medium to

heavy traffic. Interestingly, 710 participants reported driving a mere 0–10 hours per

week. However, 241 participants reported driving 11 or more hours per week.

When asked whether they had been fined for speeding in the last three years, 173

participants reported having been fined once, 62 fined twice and 25 had been fined three

or more times. Chi-square analysis of age by the number of self-reported speeding fines

in the past three years revealed no significant difference between drivers aged 17–24

years and other drivers, χ2 (df2) = 4.456, p > .05 (Table J1). This result is not surprising

as a number of young drivers aged 17–24 years may have held a licence for less than

three years. However, female drivers were significantly less likely to have received a

speeding fine in the past three years than males, ê + 2.8, p < .01, whilst males were

significantly more likely to have received two or more speeding fines in the same period

than females, ê + 3, p < .005 (refer to Table J2).

When asked about behaviours such as driving under the influence of alcohol (DUI),

unlicensed driving or other unspecified on-road offences that resulted in a loss of points,

relatively small numbers indicated that they had been fined. Therefore, chi-square

analysis of this data was not possible (see Table J3).

A reasonably large number of participants (n = 234) reported having been involved

in between one and three vehicular crashes in the past three years. A small proportion of

participants (n = 3) indicated having been involved in four to eight crashes for the same

period. Young drivers aged 17–24 years (ê + 4.4, p < .001) were significantly more

likely to have been involved in a crash in the past three years than older drivers, χ2 (df1)

= 19.2, p < .001, ø = .15 (see Table J4). No significant gender differences were found,

χ2 (df1) = .157, p > .05 (see Table J5).

Table 5.11 details the statistical tests conducted to examine age and gender

differences in the behavioural intentions of the sample. Due to the skewed distribution

of participant responses to the four intention variables, non-parametric Mann-Whitney U

Tests were utilised. The tests revealed that young drivers aged 17–24 years of age were


more likely to participate in on-road risk-taking behaviours such as speeding behaviour

and drink/drug driving than other drivers aged 25 years or more. Young drivers aged

17–24 years of age [561.68 and 582.47] had an average ranking higher than older drivers

[406.88 and 397.00] to exceed the speed limit by 10km or more on urban roads and

highways (z = -9.394, p < .001 and z = -10.521, p < .001 respectively). Drivers aged

17–24 years [479.14 and 481.29] also had average higher ranking than other drivers

[453.17 and 451.96] to drink or drug drive (z = -2.720, p < .05 and z = -4.252, p < .001

respectively). No significant gender differences were found for intention to speed on

urban roads or highways, drink drive, or drug drive (refer to Table 5.11).

Table 5.11 Driving behaviour characteristics and behavioural intentions of the sample

Variable

Drivers 17-24 Years

Drivers ≥25

Years

Male

Female

Significance

Level Driving Behaviour Characteristics

Speeding Fines in previous 3 years

% % % %

None 34.5 65.5 35.8 64.2

Age: χ2 (df2) = 4.456, p > .05, øc=.11 Gender: χ2 (df2) = 10.803, p < .05, øc=.1

One 35.5 64.5 42.2 57.8

Two or more fines 46.4 53.6 53.6 46.4

Number of Crashes in previous 3 years

Age: χ2 (df1) = 19.2, p < .001, ø = .15 Gender: χ2 (df1) = .157, p > .05, øc=.03

None

31.9 68.1 39.6 60.4

One or more

48.1 51.9 38.1 61.9

Behavioural Intentions

Mean Rank

Mean Rank

Mean Rank

Mean Rank

Speeding 10km/h or more urban roads

561.68 406.88 459.06 464.72

Age: z = -9.394, p < .001 Gender: z = -.350, p > .05

Speeding 10km/h or more highways

582.47 397.00 470.11 459.24 Age: z = -10.521, p < .001 Gender: z = -.628, p > .05

Drink Driving

479.14 453.17 469.70 457.24 Age: z = -2.720, p < .05 Gender: z = -1.26, p > .05

Drug Driving 481.29 451.96 464.98 460.91 Age: z = -4.252, p < .001 Gender: z = -.600, p > .05


5.3.5.3 Trait Characteristics of the Sample

Using 2 x 4 ANOVAs, analyses were undertaken to determine whether there were

any gender or age differences across the sample in terms of the trait aggression (AQ) and

social problem solving ability (SPSI-R) (see Appendix K). For the purpose of these

results, only significant

simple main effects and any relevant post hoc comparisons are mentioned. No

significant interactions were found.

Male participants scored significantly higher on total trait aggression than

females (p < .001, η2 = .03). Age also appeared to have a significant effect on total trait

aggression (η2 = .24), with younger drivers 17–24 years of age scoring significantly

higher trait aggression than any other age group (p < .05). In regard to the AQ

subscales, males also scored significantly higher on physical, verbal and hostile

aggression (p < .05), than females. There was no significant gender difference for angry

aggression. Significant age SMEs revealed that young drivers 17–24 years scored

significantly higher (p < .05) on all of the AQ subscales than other age groups. Post hoc

comparison also revealed that there was no significant (p > .05) difference between 25–

39 and 40–59 year old participants on physical, verbal and hostile aggression. Without

exception, participants aged 60 years and older reported significantly lower scores than

other age groups on all subscales (p < .05).

The 2 x 4 ANOVAs examining the NPO and ICS subscales of the SPSI-R were

significant (p < .001) (refer to Appendix K). Significant SMEs were found for age

groups by NPO and ICS (p < .001). Using Dunnett’s C post hoc comparisons, 17–24

year olds were significantly higher in NPO than all other age groups (p < .05) and

significantly higher in ICS than those aged 40 years and over (p < .05). A significant

SME for gender by NPO also indicated that females reported significantly higher levels

of NPO than males, although the difference was relatively small.


5.3.6 Emotional, Cognitive and Behavioural Responses to On-Road Incidents

H1 Drivers will report stronger emotional, cognitive, behavioural responses

and post-event influence in response to an intentionally anger-provoking

incident than to an ambiguous on-road incident.

Addressing H1 above, a series of pairwise t-tests were conducted to examine the

effect of on-road situational characteristics (as reflected in the two scenarios) on

participant emotional, cognitive and behavioural responses.

As detailed in Section 5.2.2.1, whilst the situation in Scenario One was

intentionally anger-provoking, Scenario Two was more ambiguous and not overtly, or

intentionally, anger-provoking. Research would suggest that the ambiguity of Scenario

Two would evoke anger in only some participants (Anderson et al., 1998). As shown in

Table 5.12, the statistical significance of these tests was predetermined at p < .025 (i.e.

using the Bonferroni adjustment .05 ÷ 2) in order to control for Type 1 error.

In summary, the results indicate that in response to Scenario One participants are

more likely to report significantly stronger negative emotion, greater levels of perceived

threat and more negative attributions than when faced with an ambiguous on-road

situation (Scenario Two). In addition, participants also reported significantly greater

likelihood of responding with both instrumental and hostile reactive aggressive

behaviours in response to Scenario One. Notwithstanding, examination of the means

would suggest that the behavioural response difference between the scenarios is more

apparent for the instrumental behaviours, rather than the hostile behaviours. When faced

with Scenario One, as opposed to the more ambiguous situation in Scenario Two,

participants also reported significantly greater likelihood of the event influencing their

subsequent behaviours, either on or off-road.


Table 5.12 Pairwise t-tests of mean emotional, cognitive and behavioural responses to

Scenarios One and Two

Variables by

Scenario

M

SD

Emotional & Cognitive Response Negative Emotion Scenario One

2.97***

1.04

Scenario Two 2.50 1.09 Threat Scenario One Scenario Two

2.53*** 1.18

1.31 .52

Negative Attributions Scenario One Scenario Two

3.36*** 2.14

1.15 1.12

Behavioural Response Instrumental Behavioural Response Scenario One Scenario Two

1.96*** 1.87

.75 .73

Hostile Behavioural Response Scenario One Scenario Two

1.07** 1.05

.35 .29

Post-Event Influence Scenario One Scenario Two

1.51*** 1.25

.74 .55

** p<.025, *** p<.001

5.3.7 Examination of the Components Proposed in the Theoretical Framework of

Aggressive Driving

The following analyses were undertaken to test hypotheses 2–8 detailed in

Section 5.1.1. As detailed in Section 5.2.2, in order to explore the psychological

components of the GAM (Anderson & Bushman, 2002) that have been found potentially

relevant to aggressive driving behaviour, the use of hierarchical regression analyses was

considered appropriate. This approach allows for exploration of the various stages of

the GAM based framework for aggressive driving. Specifically, a three stage analysis of


the model was utilised, in accordance with the diagrammatic presentation at Figure 5.1.

The first stage of the exploration examined the relationships between the socio-

demographic, state and trait person-related characteristics of participants in relation to

their emotional and cognitive responses to Scenario One and Scenario Two. The second

stage involved an examination of the relationship of the socio-demographic, trait and

state person-related characteristics, and participant emotional and cognitive responses

with the likelihood of either an instrumental and/or hostile aggressive behavioural

response. The final stage examined how these variables relate to the likelihood of a

post-event influence. Prior to these analyses, the bivariate relationships between the

relevant variables were examined to identify those for inclusion in the regression

analyses.

5.3.7.1 Bi-variate Correlations of Variables for Consideration in the Examination of

the Components of the Framework

As detailed in Table 5.13, there were many person-related characteristics and a

small number of socio-demographic variables that were significantly correlated to a

participant’s emotional, cognitive and behavioural response to Scenarios One and Two,

p < .001. As previously explained, the initial response comprises negative emotions,

feelings of threat and attributions, whilst the behavioural responses consist of

instrumental and hostile aggressive behavioural responses. A number of significant

associations, with correlations approaching .2 or greater, are discussed below. In some

instances, however, significant associations with correlations below .2 are mentioned for

ease of reference.

5.3.7.1.1 Driving Exposure and Socio-Demographic Variables. The type of

vehicle driven had a small but significant relationship with negative emotions in

response to Scenario One only (r = -.11, p < .001). Therefore, it was not incorporated

into the regression analyses exploring the components of the model. Similarly,

congestion and hours driven per week were not significantly correlated with the DV. As

such, they were not included in the regression analyses. However, participant age,

gender and education level attained were included in the regression analyses as they had

multiple significant relationships with variables across Scenarios One and Two. These

relationships will be highlighted in more detail below.


5.3.7.1.2 Negative Emotions. Several of the variables were significantly

correlated with the strength of negative emotions reported as a result of exposure to both

Scenarios One and Two (refer to Table 5.14). Participant total AQ scores (S1, r = .42, p

< .001 and S2, r = .49, p < .001)

were significantly related to the negative emotions reported following exposure to

Scenarios One and Two. Examination of the SPSI-R subscales also revealed NPO (S1, r

= .33, p < .001 and S2, r = .33, p < .001) and ICS (S1, r = .19, p < .001 and S2 , r = .18,

p < .001) are positively, albeit moderately, associated with negative emotions, indicating

that as negative problem-solving orientation and/or impulsive/careless style of problem

solving increase so does the amount of negative emotion reported by participants. The

strength of the associations is similar for both scenarios, indicating that higher levels of

NPO and ICS brought to either on-road situation will result in similar levels of negative

emotion. The RPS subscale was not significantly associated with negative emotions

reported by participants in response to either situation (p > .05).

As a measure of state characteristics, the participant’s reported pre-study

emotions were significantly (S1, r = .32, p < .001 and S2 , r = .34, p < .001), but

moderately correlated with the DV. This result indicates that if participants reported

greater positive emotions prior to completing the questionnaire they were more likely to

report less negative emotions in response to either scenario. The presence of this

significant association would indicate, once again, a need to account for pre-study

emotions in the following hierarchical regression analyses.

5.3.7.1.3 Perceived Threat. Gender had a significant association with threat in

response to Scenario One only (r = -.30, p < .001), indicating that females were more

likely to perceive threat in such a situation. However, all other state and trait variables

had a significant relationship with perceived threat in response to Scenarios One and

Two: age (S1, r = -.19, p < .001 and S2 , r = -.13, p < .001); total AQ (S1, r = -.12, p <

.001 and S2, r = .21, p < .001), NPO (S1, r = .28, p < .001 and S2 , r = .22, p < .001);

ICS (S1, r = .07, p < .05 and S2 , r = .08, p < .05); and, pre-study emotion (S1, r = .18, p

< .001 and S2 , r = .14, p < .001). These results indicate that as age decreases and

negative orientation and impulsive/careless style of problem solving increases so does

the likelihood of perceiving threat in response to both scenarios. Interestingly, the


correlations for trait aggression indicate that in response to Scenario One, lower levels of

trait aggression were associated with the experience of ‘threat’. Conversely, for

Scenario Two higher levels of trait aggression were associated with reported feelings of

‘threat’.

The correlation of education levels with feelings of threat in response to Scenario

One was also significant (r = .07, p < .05) suggesting that as education level increases so

does the likelihood of perceiving ‘threat’ in such a situation. The type of vehicle driven,

levels of congestion most frequently encountered and hours driven per week also had

small to moderate, significant relationships with perceived threat in response to Scenario

One (r = -.11, p < .001, r = -.12, p < .001, r = -.13, p < .001 respectively). These results

indicate that those drivers more likely to perceive threat will drive smaller vehicles, will

more frequently drive in light–medium levels of congestion and drive approximately 1–

16 hours per week. However, as these variables were only significant with regard to

Scenario One, they were not included in the regression analyses that follow.

5.3.7.1.4 Negative Attributions. There was a significant relationship between

the total AQ scores and negative attributions (S1, r = -.26, p < .001 and S2 , r = -.25, p <

.001), as well as the two SPSI-R subscales, NPO and ICS in response to both scenarios

(NPO - S1, r = .15, p < .001 and S2 , r = .22, p < .001; ICS - S1, r = .12, p < .001 and

S2 , r = .16, p < .001). These latter results indicate that higher scores on negative

problem orientation and impulsive/careless style are associated with experiencing

negative attributions in response to potentially anger-provoking on-road incidents. Pre-

study emotions were also found to be positively, though weakly (S1, r = .16, p < .001

and S2, r = .21, p < .001) related to the likelihood of negative attributions, with higher

levels of negative, pre-study emotion being associated with a greater likelihood of

having negative attributions in response to an on-road incident.

5.3.7.1.5 Instrumental Behavioural Response. Of the trait characteristics

measured, AQ scores (S1, r = .57, p < .001 and S2 , r = .59, p < .001) and two of the

SPSI-R subscales, NPO (S1, r = .21, p < .001 and S2 , r = .28, p < .001) and ICS (S1, r

= .28, p < .001 and S2 , r = .24, p < .001) were found to have significant, positive


Table 5.13 Bivariate correlations of the person-related, driving exposure, emotional, cognitive and behavioural responses, and post-event influence variables – Scenario One (S1) and Scenario Two (S2) (N=926)

Variable

Negative Emotions

Feelings of Threat

Negative

Attributions

Likelihood of

Instrumental Behavioural

Response

Likelihood of

Hostile Behavioural

Response

Likelihood

of Post-event Influence

S1

S2

S1

S2

S1

S2

S1

S2

S1

S2

S1

S2

Gender1

.12***

.03

-.30***

-.02

-.05

-.03

-.05

-.03

-.11***

-.06

.17***

.06

Agea

-.44***

-.45***

-.19***

-.13***

-.41***

-.42***

-.41***

-.42***

-.08*

-.04

-.23***

.18***

Total AQ Score

.42***

.49***

-.12***

.21***

.57***

.59***

.57***

.59***

.32***

.19***

.32***

.29***

NPO

.33***

.33***

.28***

.22***

.21***

.28***

.21***

.28***

.07*

.19***

29***

.25***

ICS

.19***

.18***

.07*

.08*

.28***

.24***

.28***

.24***

.18***

.10***

.14***

.16***

RPS

-.05

-.06

-.01

-.06

-.06

-.08*

-.06

-.08*

-.07*

-.05

-.03

-.04

Pre-Study Emotion

.32***

.34***

.18***

.14***

.31***

.31***

.31***

.31***

.11***

.10***

.31***

.21***

Education Levelb (< Yr 10 or > Yr 10)

.16*** .19*** .07*

.04 .19*** .23*** .19*** .23*** .05 .02 .10*** .11***

Type of Vehiclec -11*** -.06 -.11*** -.01 -.06 -.04 -.06 -.04 -.08* .06 -.10*** -.04

Congestionc -.04 -.01 -.12*** -.02 .05 .02 .05 .02 .05 .03 -.04 -.03

Hours Driven Per Week

-.00 .01 -.13*** -.01 .05 .04 .05 .04 .06 .02

-.07* -.04

*** p < .001 ** p < .01 * p < .05 a. Age variable was recoded to reflect midpoints of original categories. b. Education Level was collapsed. c. The categorical variable, congestion was rank ordered from lowest to highest levels of each variable to enable Spearman’s rho measure of association (rs). Also, the categorical variable ‘type of vehicle’ was also rank ordered from small vehicles to larger vehicles such as trucks to enable Spearman’s rho measure of association (rs). 1 In order to explore for any gender by age differences in participant responses, two way ANOVAs were conducted on the responses to Scenario One. A conservative probability of α = .008 (.05 ÷ 6 = .008) was chosen consistent with the number of tests performed. Post hoc test used Dunnett’s C at p <.05. All of the overall ANOVAs were significant at p < .001, however, only one interaction was evident between age and gender for likelihood of a hostile aggressive response [F (3,918) = 4.89, p < .008] although the effect size was small ή2= .02. Males were more likely to adopt a hostile behavioural response than females (p < .001) and 17-24 year old drivers were significantly more likely to adopt such behaviour than drivers aged 25-39 and 60 years and over (p < .001). Significant SMEs were also found for ‘perceived threat’ and ‘likelihood of a post-event influence’ (p < .05). In respect of both variables, females were significantly more likely than males to experience feelings of ‘threat’ and a ‘post-event influence’. Drivers 17-39 years of age were also significantly more likely to experience feelings of threat than drivers aged 40 years and over (p < .05). Of the other significant SMEs, post host tests revealed that 17-24 year old drivers were significantly more likely to experience negative emotions and adopt instrumental behavioural responses than any other age group (p < .05). However, there was no significant difference between drivers 25-39 and 40-59 years of age on the likelihood of adopting an instrumental behavioural response (p < .05). Examination of the means generally indicate that as age increases the emotional and cognitive response, behavioural response and likelihood of a post-event influence decreases.


relationships with the likelihood of an instrumental aggressive behavioural response to

both scenarios. The relationship of total AQ scores to the likelihood of adopting

instrumental aggression in response to either scenario, was particularly strong.

Another relatively weak, yet positive relationship was found between education

attained (‘0’ < Yr 10 and ‘1’ > Yr 10) and the DV in response to both scenarios (S1 - rpb

= .19, p < .001 and S2 - rpb = .23, p < .001 ), indicating that participants with greater

than a Year 10 education were more likely to have an instrumental aggressive

behavioural response to both scenarios.

The measure of participant state characteristics i.e. pre-study emotion, was also

found to be positively correlated with the likelihood of an instrumental aggressive

behavioural response in both situations (S1 - r = .31, p < .001 and S2 - r = .31, p <

.001).

5.3.7.1.6 Hostile Aggressive Behavioural Response. The results revealed two

interesting and significant relationships (p < .001). The total AQ scores were found to

have a positive relationship with the likelihood of a hostile aggressive behavioural

response to both scenarios (S1 - r = .32, p < .001 and S2 - r = .19, p < .001). Similarly,

ICS scores were also positively correlated with the likelihood of a hostile aggressive

behavioural response in both of the scenarios, albeit weakly (S1 - r = .18, p < .001 and

S2 - r = .10, p < .001).

5.3.7.1.7 Post-Event Influence. The bi-variate correlations of the state and trait

person-related and driving exposure variables with the likelihood of a post-event

influence following Scenario One revealed four significant, moderate associations equal

to, or approaching r = .2 at p < .001: age (r = -.23, p < .001), total AQ (r = .32, p <

.001), NPO (r = .29, p < .001) and pre-study emotions (r = .31, p < .001). Similarly,

these variables were significantly correlated with participant responses to Scenario Two:

age (r = .18, p < .001), total AQ (r = .29, p < .001), NPO (r = .25, p < .001) and pre-

study emotions (r = .21, p < .001). However, the correlation between age and the

likelihood of a post-event influence in response to Scenario One was negative, indicating

that younger drivers would be more affected after such an incident. Conversely, the age

correlation with the likelihood of a post-event influence in response to Scenario Two

suggests that older drivers will be more affected.


The correlations for total AQ, NPO and pre-study emotions indicate that as trait

aggression levels, negative problem orientation and negative pre-study emotions

increase, the likelihood of a post-event influence also increases in response to both

scenarios.

5.3.7.1.8 Self-Reported Measures for the Two Scenarios. The bi-variate

correlations of the emotional, cognitive, behavioural and post-event influence variables

with the self-reported participant responses to Scenarios One and Two are included in

Table 5.14. As would be expected, multiple significant correlations (p < .05) were

found between the participant responses to Scenarios One and Two. Significant

correlations of .10, .30 and .50 have been interpreted as weak, moderate and strong

respectively, consistent with other behavioural science research (Green, Salkind, &

Akey, 2000).

Two of the emotional and cognitive response variables for Scenario One were

moderately to strongly related to the same emotional and cognitive response variables

for Scenario Two: negative emotions (r = .51) and negative attributions (r = .37).

However, there was evidence of only a weak to moderate relationship between the

perceived threat reported in Scenarios One and Two (r = .21). The behavioural response

variables for Scenario One were strongly associated with the behavioural response

variables for Scenario Two ranging from r = .48 to r = .65. Though the emotional and

cognitive variables in response to Scenario One appeared to have a significant

association with the likelihood of an instrumental behavioural response to Scenario Two,

there were no significant relationships between the Scenario One emotional and

cognitive response variables and the likelihood of a hostile aggressive behavioural

response to Scenario Two. The behavioural response variables for Scenario One were

also significantly associated with Scenario Two emotional and cognitive responses,

although the associations varied from weak to moderately strong.


Table 5.14 Bivariate correlations of participant negative emotion, threat, negative

attributions, likelihood of behavioural response and post-event influence - Scenarios

One and Two

Negative Emotions

(S2)

Threat (S2)

Negative

Attributions (S2)

Likelihood of an

Instrumental Behavioural

Response (S2)

Likelihood of a Hostile

Behavioural Response (S2)

Post-event Influence

(S2)

Emotional & Cognitive Responses Negative Emotions (S1)

.51***

.40***

.51***

.42***

.02

.15***

Threat (S1)

.23***

.21***

.10**

.14***

-.01

.14***

Negative Attributions (S1)

.29***

.09**

.37***

.29***

-.01

.05 Behavioural Responses Likelihood of Instrumental Behavioural Response (S1)

.45***

.17***

.39***

.65***

.19***

.14***

Likelihood of a Hostile Behavioural Response (S1)

.12***

.24***

.19***

.31***

.58***

.15***

Post-event Influence (S1)

.30***

.23***

.19***

.26***

.12***

.48***

*** p < .05, ** p < .01, * p < .05

5.3.7.2 Regression Analyses of Socio-Demographic, Trait and State Person-Related

Variables on Participant Emotional, Cognitive and Behavioural Responses

Tables 5.15 and 5.16 report the results of the hierarchical regression analyses

conducted for Scenarios One and Two respectively. These analyses were undertaken to

further test hypotheses 2 to 8. Further to Section 5.3.7, total pre-study emotions were

also found to have a moderate, significant association with the negative emotional

responses reported by participants (S1 - r =.32, p < .001 and S2 – r = .34, p < .001) (see

Table 5.15). As such, in the regression analyses it was considered necessary to account

for total pre-study emotion, as a measure of ‘state’ stress. Therefore, pre-study emotions

were entered into the hierarchical regressions after the more enduring trait, person-

related predictor variables as detailed in Blocks 1 and 2 of the following analyses.


Table 5.15 Hierarchical regression of socio-demographic, trait and state person-

related variables on participant negative emotion responses to Scenario One (n = 926)

Variables

M

SD

B

Std. Error

β

sr2

Adj R2

∆R2

Block One

Age1

40.5

19.6

-.014***

.002

.046

.05

Gender

.100

.064

-.264

Education Level2

.009

.085

.003

.19*** Block Two

Total AQ

47

15.6

.014***

.003

.204

.02

NPO

5.2

.52

.279***

.065

.139

.01

ICS

5.2

.54

-.004

.061

-.002

RPS

3.3

.87

-.007

.035

-.006

.27*** .08*** Block Three

Pre-study Emotion

2.0

.77

.124*

.044

.091

.01

.28*** .01* 1. Age variable recoded to reflect midpoints of original categories. 2. Education level was recoded into a dichotomous variable. *** p < .001 * * p < .01 * p < .05

5.3.7.2.1 Negative Emotions. The overall regression analyses for Scenarios One

and Two were significant, F (8, 917) = 44.82, p < .001, R2 = .28 and F (8, 917) = 54.15,

p < .001, R2 = .32 respectively (refer to Tables 5.15 and 5.16). Socio-demographic

variables contributed a significant amount of the variance in the negative emotional

responses reported by participants in response to both scenarios [F (3, 922) = 72.44, p <

.001, R2 = .19 and F (3, 922 ) = 78.18, p < .001, R2 = .20 respectively]. The trait, person-

related variables also contributed a significant amount of the variance over and above

the socio-demographic variables [S1 - F (4, 918) = 26.68, p < .001, R2 Change = .08 and

S2 - F (4, 918) = 37.84, p < .001, R2 Change = .11].



related variables on participant negative emotion responses to Scenario Two (n=926)

Variables

M

SD

B

Std. Error

β

sr2

Adj R2

∆R2

Block One

Age1

40.5

19.6

-.015***

.002

-.263

.05

Gender

-.081

.065

-.036

Education Level2

.044

.087

.015

.20*** Block Two

Total AQ

47

15.6

.019***

.003

.271

.04

NPO

5.2

.52

.295***

.067

.141

.01

ICS

5.2

.54

-.064

.062

-.031

RPS

3.3

.87

-.023

.036

-.019


Pre-study Emotion

2

.77

.121*

.045

.084

.01

.32*** .01* 1. Age variable recoded to reflect midpoints of original categories. 2. Education level was recoded into a dichotomous variable. *** p < .001 ** p < .01 * p < .05

In response to both scenarios, three of the trait predictor variables were

significant: age (S1 - β = .046, p < .001 and S2 - β = -.263, p < .001), total AQ (S1 -

β = .204, p < .001 and S2 - β = .271, p < .001), and NPO (S1 - β = .139, p < .001 and

S2 - β = .141, p < .001). These results suggest that younger drivers are more likely to

experience higher levels of negative emotion in response to either situation. They also

indicate that higher trait aggression levels and negative orientation towards problem

solving (NPO) increases the likelihood of a negative emotional response in both

situations.

Having controlled for the socio-demographic and trait person-related variables,

pre-study emotions reported by participants contributed a significant, but small amount

of additional variance in the self-reported negative emotion for Scenario One and Two


[F (1, 917) = 7.76, p < .05, R2 Change = .01 and F (1, 917) = 7.09, p < .05, R2

Change = .01 ].

As such, participants who reported higher levels of negative emotion prior to completing

the questionnaire tended to record higher levels of negative emotion in response to the

scenarios. However, the R2 statistics indicate that pre-study emotions added only a small

amount to the overall variance in self-reported negative emotions in response to

Scenario One and Two.

5.3.7.2.2 Perceived Threat. The overall regression of socio-demographic, trait

and state person-related characteristics on self-reported levels of perceived threat was

significant for both scenarios [F (8, 917) = 21.22, p < .001, R2 = .15 and F (8, 917) =

8.2, p < .001, R2 = .06] (refer to Tables 5.17 and 5.18). Socio-demographic data

contributed a significant amount of the variance in self-reported threat in response to

Scenarios One and Two [S1 - F (3, 922) = 36.73, p < .001, R2 = .11 and S2 - F (3, 922) =

5.61, p < .001, R2 = .02]. However, gender was the only uniquely significant predictor

variable of perceived threat in response to Scenario One, females being more likely to

experience the emotion (S1-β = .238, p < .001). None of the socio-demographic

variables listed contributed significantly to the likelihood of perceived threat in response

to Scenario Two.

In the second step, the trait person-related variables also contributed to a

significant proportion of the variance in perceived threat having controlled for the socio-

demographic variables [S1 - F (4, 918) = 12.04, p < .001, R2 Change = .05 and S2 - F (4,

918) = 11.91, p < .001, R2 Change = .05].

In the case of Scenario One, NPO uniquely added a significant proportion of the

variance in reported perceived threat (β = .212, p < .001), suggesting that those

participants with higher levels of negative problem orientation were more likely to

report feeling threatened in response to Scenario One. Similarly, in response to Scenario

Two, NPO scores contributed to a significant proportion of the variance in self-reported

threat (β = .155, p < .001). Notably, participant total AQ scores were also significant

predictors of the likelihood of perceiving threat in response to Scenario Two (β = .126,

p < .05). The latter result may suggest that in a more ambiguous, anger-provoking

scenario, higher trait aggression scores will increase the likelihood of detecting or

perceiving threat.



related variables on participant perceived threat responses to Scenario One (n = 926)

Variables

M

SD

B

Std. Error

β

sr2

Adj R2

∆R2

Block One

Age1

40.5

19.6

-.004

.003

-.064

Gender

.639***

.087

.238

.05

Education Level2

.115

.115

.033

.11*** Block Two

Total AQ

47

15.6

-.001

.003

-.014

NPO

5.2

.52

.531***

.089

.212

.03

ICS

5.2

.54

-.052

.082

-.021

RPS

3.3

.87

.051

.047

.034


Pre-study Emotion

2

.77

.140***

.060

.082

.01

.17*** .01*** 1. Age variable recoded to reflect midpoints of original categories. 2. Education level was recoded into a dichotomous variable. *** p < .001 ** p < .01 * p < .05

In the final step, the entry of pre-study emotions added significantly only to the

likelihood of perceived threat in response to Scenario One, but only minimally [S1 - F

(1, 917) = 5.36, p < .05, R2 Change = .01 and S2 - F (1, 917) = .40, p > .05, R2

Change = .00].



related variables on participant perceived threat responses to Scenario Two (n = 926)

Variables

M

SD

B

Std. Error

β

sr2

Adj R2

∆R2

Block One

Age1

40.5

19.6

-.001

.001

-.037

Gender

-.014

.036

-.013

Education Level2

-.019

.048

-.014

.02*** Block Two

Total AQ

47

15.6

.004*

.001

.126

.01

NPO

5.2

.52

.154***

.037

.155

.02

ICS

5.2

.54

-.023

.034

-.024

RPS

3.3

.87

-.017

.020

-.028


Pre-study Emotion

2

.77

.016

.025

.024

.07*** .00 1. Age variable recoded to reflect midpoints of original categories. 2. Education level was recoded into a dichotomous variable. *** p < .001 ** p < .01 * p < .05

5.3.7.2.3 Negative Attributions. The regression model for person-related factors

on the likelihood of negative attributions in response to Scenarios One and Two are

detailed in Tables 5.19 and 5.20. The overall regression analyses for both scenarios

were significant [F (8, 917) = 14.16, p < .001, R2 = .10 and F (8, 917) = 22.73, p < .001,

R2 = .16].



related variables on participant negative attributions in response to Scenario One (n =

926)

Variables

M

SD

B Std.

Error β

sr2

Adj R2

∆R2

Block One

Age1

40.5

19.6

-.010***

.002

-.172

.02

Gender

.024

.078

.010

Education Level2

-.193

.104

-.063

.07*** Block Two

Total AQ

47

15.6

.016***

.003

.217

.03

NPO

5.2

.52

.016

.080

.007

ICS

5.2

.54

.005

.074

.002

RPS

3.3

.87

-.031

.043

-.023


Pre-study Emotion

2

.77

.020

.054

.013


The first step in the analyses for both scenarios was significant [S1 - F (3, 922) =

23.34, p < .001, R2 = .07 and S2 - F (3, 922) = 27.40, p < .001, R2 = .08], indicating that

socio-demographic factors contribute significantly to the variance in negative emotions

experienced on the road. However, participant age proved to be the only significant

predictor variable in both scenarios (S1 -β = -.172, p < .001, sr2 = .02 and S2 - β = -

.129, p < .001, sr2 = .01), indicating that younger drivers are more likely to make

negative attributions in response to the two scenarios. In response to Scenario Two,

gender was also found to be a significant predictor (β = -.106, p < .001, sr2 = .01);

males being more likely to make negative attributions in response to Scenario Two.



related variables on participant negative attributions in response to Scenario Two (n =

926)

Variables

M

SD

B Std.

Error β

sr2

Adj R2

∆R2

Block One

Age1

40.5

19.6

-.007***

.002

-.129

.01

Gender

-.243***

.073

-.106

.01

Education Level2

-.081

.098

-.027

.08*** Block Two

Total AQ

47

15.6

.019***

.003

.258

.04

NPO

5.2

.52

.179*

.075

.084

.01

ICS

5.2

.54

.000

.070

.000

RPS

3.3

.87

-.097*

.040

-.075

.01


Pre-study Emotion

2.0

.77

.038

.051

.026


In step two, trait person-related characteristics were also found to contribute a

significant amount of the variance in negative attributions in response to both scenarios

[S1 - F (4, 918) = 10.12, p < .001, R2 Change = .04 and S2 - F (4, 918) = 22.85, p < .001,

R2 Change = .08], over and above the socio-demographic person-related measures. The

Scenario One regression revealed only one significant trait predictor of negative

attributions, total AQ (β = .217, p < .001, sr2 = .03), with higher AQ scores being

associated with an increased likelihood of negative attributions. In contrast, the

regression on Scenario Two found three individually significant trait predictor variables:

AQ scores (β = .258, p < .001, sr2 = .04), NPO (β = .084, p < .05, sr2 = .01) and RPS


(β = -.075, p < .05, sr2 = .01). These results indicate that higher AQ scores, higher NPO

scores and lower RPS scores are associated with an increased likelihood of negative

attributions in response to Scenario Two.

In the final step, pre-study emotion failed to contribute significantly to the

likelihood of negative attributions in response to either Scenario One or Two [S1 - F (1,

917) = .14, p > .05, and S2 - F (1, 917) = .56, p > .05].

5.3.7.3 Regression of Socio-Demographic, Trait and State Person-Related and

Emotional and Cognitive Response Variables on Participant Behavioural

Responses

5.3.7.3.1 Likelihood of an Instrumental Behavioural Response. The regression

of the socio-demographic, trait and state person-related and emotional and cognitive

response variables on the likelihood of an instrumental behavioural response to

Scenarios One and Two are detailed in Tables 5.21 and 5.22 respectively. As can be

seen in the tables, the overall regression analyses were significant [S1 - F (11, 914) =

76.31, p < .001, R2 = .47, and S2 - F (11, 914) = 106.24, p < .001, R2 = .56].

The first step in both regression analyses was significant, suggesting that

participant socio-demographic characteristics contribute to a significant amount of

variance in the DV in response to both scenarios [S1 - F (3, 922) = 69.63, p < .001, R2 =

.19 and S2 - F (3, 922) = 76.46, p < .001, R2 = .20].

In the second step of each analysis, trait person-related characteristics were also

found to contribute a significant proportion of the variance in response to each scenario


R2 Change = .19]. Entry of pre-study emotions to both analyses, in step three, was not

significant [S1 - F (1, 917) = 2.2, p > .05, and S2 - F (1, 917) = .16, p > .05]. However,

in the final step, entry of the emotional and cognitive response variables yielded a

significant proportion of the variance in the likelihood of instrumental aggression in

response to both scenarios [S1 - F (3, 914) = 68.86, p < .001, R2 Change = .12 and S2 - F

(3, 914) = 120.21, p < .001, R2 Change = .17].

The regression performed on Scenario One identified a number of individually

significant socio-demographic, person-related and emotional and cognitive predictors of


the likelihood of an instrumental behavioural response including: age (β = -.073, p <

.05, sr2 = .00); total AQ (β = .345, p < .001, sr2 = .06); NPO (β = -.079, p < .05, sr2 =

.00; ICS (β = .088, p < .001, sr2 = .01); negative emotions (β = .356, p < .001, sr2 =

.07); perceived threat (β = -.091, p < .001, sr2 = .01); and negative attributions (β =

.114, p < .001, sr2 = .01). However, it is acknowledged that many of these predictors

account for a very small, unique amount of the variance in the dependent variable.

Indeed, much of the variance appears to be shared.


related and emotional and cognitive response variables on participant instrumental

response to Scenario One (n = 926)

Variables

M

SD

B

Std. Error

β

sr2

Adj R2

∆R2

Block One Age1

40.5

19.6

-.003*

.001

-.073

.00

Gender

-.066

.040

-.043

Education Level2

.046

.052

.023

.19*** Block Two Total AQ

47

15.6

.017***

.002

.345

.06

NPO

5.2

.52

-.113*

.041

-.079

.00

ICS

5.2

.54

.123***

.037

.088

.01

RPS

3.3

.87

-.014

.021

-.017

.37*** .18*** Block Three Pre-study Emotion

2

.77

.019

.027

.019

.37*** .00 Block Four Negative Emotions (S1)

3

1.1

.255***

.023

.356

.07

Perceived Threat (S1)

2.5

1.3

-.052***

.016

-.091

.01


3.4

1.2

.075***

.018

.114

.01




related and emotional and cognitive response variables on participant instrumental

response to Scenario Two (n = 926)

Variables

M

SD

B Std.

Error β

sr2

Adj R2

∆R2

Block One

Age1

40.5

19.6

-.002*

.001

-.064

.00

Gender

-.017

.035

-.011

Education Level2

.096*

.047

.049

.00

.20*** Block Two

Total AQ

47

15.6

.015***

.001

.320

.05

NPO

5.2

.52

-.024

.036

-.017

ICS

5.2

.54

.039

.033

.028

RPS

3.3

.87

-.018

.019

-.021


Pre-study Emotion

2

.77

-.020

.024

-.021

.39*** .00 Block Four

Negative Emotions (S2)

2.5

1.1

.212***

.022

.318

.05


1.9

.52

-.001

.033

-.001


2.1

1.1

.150***

.019

.229

.03



In comparison, the regression conducted on Scenario Two identified only four

individually significant predictor variables: age (β = -.064, p < .05, sr2 = .00);

education level (β = .049, p < .05, sr2 = .00); total AQ (β = .320, p < .001, sr2 = .05);

negative emotions (β = .318, p < .001, sr2 = .05); and negative attributions (β = .229,

p < .001, sr2 = .03). Again, however, individually these variables do not appear to

account for much of the unique variance in the likelihood of adopting an instrumental

behavioural response.

The above results indicate that those drivers who were more likely to report an

instrumental behavioural response to Scenario One were more likely to be younger and

have higher trait aggression levels. They were also more likely to have higher levels of

impulsive/careless style (ICS) problem solving. With regard to emotional and cognitive

response variables, those drivers more likely to adopt an instrumentally aggressive

response were more likely to experience higher levels of negative emotion and negative

attributions in response to the scenario, whilst being more likely to perceive less threat.

In response to the more ambiguous, yet potentially anger-provoking scenario

(Scenario Two), total AQ, negative emotions and negative attributions appear to be the

only unique significant predictors. This would suggest that in an ambiguous, anger-

provoking situation, those high on trait aggression will tend to adopt instrumental

aggression. They are also more likely to experience higher levels of negative emotions

and more negative attributions in response to such an on-road situation, prior to adopting

an instrumental behavioural response.

5.3.7.3.2 Likelihood of a Hostile Behavioural Response. As shown in Tables

5.23 and 5.24, the overall regression analyses of the relevant factors on the likelihood of

a hostile behavioural response were significant, albeit accounting for a relatively small

amount of variance [S1 - F (11, 914) = 12.68, p < .001, R2 = .12, and S2 - F (11, 914) =

13.70, p < .001, R2 = .13]. The first step in the regression analyses of the socio-

demographic variables on the likelihood of a hostile behavioural response was

significant for Scenario One only [S1 - F (3, 922) = 6.87, p < .001, R2 = .02, and S2 - F

(3, 922) = 1.79, p > .05].

Having controlled for socio-demographic variables, step two revealed a

significant contribution by the trait person-related variables in the prediction of hostile


behavioural responses to both Scenarios One and Two [S1 - F (4, 918) = 28.75, p < .001,

R2 Change = .11, and S2 - F (4, 918) = 9.07, p < .001, R2

Change = .04]. Step three revealed

no significant contribution by pre-study emotions to the prediction of hostile behaviour

in response to either scenario [S1 - F (1, 917) = .63, p > .05, and S2 - F (1, 917) = .46, p

> .05]. Finally, having controlled for all other variables, the emotional and cognitive

response variables were found to significantly contribute to the likelihood of a hostile

behavioural response to Scenario Two only [S1 - F (3, 914) = .36, p > .05, and S2 - F (3,

914) = 34.6, p < .001, R2 Change = .10].

For Scenario One, there were two predictor variables that significantly

contributed to a proportion of the variance in the likelihood of a hostile behavioural

response: total AQ (β = .369, p < .001, sr2 = .07); and ICS (β = .102, p < .001, sr2 =

.01). These results indicate that higher levels of trait aggression and impulsive/careless

style problem solving are significantly associated with a greater likelihood of hostile

aggression in response to an anger-provoking on-road situation (i.e. Scenario One). In

comparison, analysis of Scenario Two revealed three statistically significant predictor

variables: total AQ (β = .178, p < .001, sr2 = .02); negative emotions (β = -.169, p <

.001, sr2 = .01); and perceived threat (β = .321, p < .001, sr2 = .09). Again, higher

levels of AQ were associated with an increased likelihood of adopting hostile

aggression. As can be seen in response to Scenario Two, significantly lower levels of

negative emotion were associated with an increased likelihood of hostile aggression,

whilst higher self-reported levels of perceived threat were associated with the increased

likelihood of hostile behaviour.

Upon examination of the unique variance (sr2) contributed by the predictors, the

results suggest that total trait aggression scores account for a larger proportion of the

variance in the dependent variable, especially in terms of Scenario One. However,

perceived threat accounted for a larger proportion of the variance in the dependent

variable in response to Scenario Two. Again, in the analysis of both scenarios a

considerable amount of variance remains unexplained.



related and emotional and cognitive response variables on participant hostile response

to Scenario One (n = 926)

Variables

M

SD

B

Std. Error

β

sr2

Adj R2

∆R2

Block One

Age1

40.5

19.6

.001

.001

.073

Gender

-.044

.024

-.062

Education Level2

-.010

.031

-.011

.02*** Block Two

Total AQ

47

15.6

.008***

.001

.369

.07

NPO

5.2

.52

-.045

.025

-.068

ICS

5.2

.54

.066***

.022

.102

.01

RPS

3.3

.87

-.020

.013

-.051


Pre-study Emotion

2

.77

-.013

.016

-.028



3

1.1

-.012

.014

-.036


2.5

1.3

.007

.009

.028


3.4

1.2

.003

.011

.010

.13*** .00 1. Age variable recoded to reflect midpoints of original categories 2. Education level was recoded into a dichotomous variable. *** p < .001 ** p < .01 * p < .05



related and emotional and cognitive response variables on participant hostile response

to Scenario Two (n = 926)

Variables

M

SD

B

Std. Error

β

sr2

Adj R2

∆R2

Block One

Age1

40.5

19.6

.000

.001

.031

Gender

-.019

.020

-.032

Education Level2

-.003

.026

-.004

.01*** Block Two

Total AQ

47

15.6

.003***

.001

.178

.02

NPO

5.2

.52

-.014

.021

-.025

ICS

5.2

.54

.023

.019

.042

RPS

3.3

.87

-.010

.011

-.029


Pre-study Emotion

2

.77

.012

.014

.031



2.5

1.1

-.046***

.012

-.169

.01


1.9

.52

.184***

.019

.321

.09


2.1

1.1

.016

.011

.059



5.3.7.4 Regression of Socio-Demographic, Trait and State Person-Related, Emotional

and Cognitive Response and Behavioural Response Variables on the Likelihood

of a Post-Event Influence

The relevant regression analyses for Scenarios One and Two are detailed at

Tables 5.25 and 5.26. The overall regression analyses for both scenarios were

significant [S1 - F (13, 912) = 22.89, p < .001, R2 = .24 and S2 - F (13, 912) = 19.11, p <

.001, R2 = .20].

The first step in the analyses revealed socio-demographic variables contributed a

significant proportion of the variance in the likelihood of a post-event influence in

response to both scenarios [S1 - F (3, 922) = 23.34, p < .001, R2 = .07, and S2 - F (3,

922) = 10.38, p < .001, R2 = .03]. The second step in the analyses also found that trait

person-related variables contributed to a significant amount of the variance in the

likelihood of a post-event influence, over and above the socio-demographic variables


R2 Change = .08]. The subsequent entry of the pre-study emotions for Scenario One,

resulted in a small but significant change in the variance, F (1, 917) = 19.88, p < .001, R2

Change = .02. Conversely, the entry of pre-study emotions for Scenario Two did not

significantly add to the variance in the likelihood of a post-event influence, F (1, 917) =

2.93, p > .05.

In the fourth step, entry of the emotional and cognitive response variables in the

regressions for both Scenarios One and Two revealed significant change in the variance

explained [S1 - F (3, 914) = 25.63, p < .001, R2 Change = .06, and S2 - F (3, 914) = 31.14,

p < .001, R2 Change = .08]. In the final step, the likelihood of adopting an instrumental

and/or hostile behavioural response was entered into the regression equation, having

controlled for all other variables. For Scenario Two, the likelihood of the behavioural

responses added a significant though small amount of additional variance in the

likelihood of a post-event influence, F (2, 912) = 10.18, p < .001, R2 Change = .02.

However, the same step applied to Scenario One was not significant, F (2, 912) = 1.2, p

> .05.

As can be seen in Table 5.25, the regression for Scenario One revealed several

individually significant predictors worthy of mention: gender (β = .085, p < .05, sr2 =


.01); total AQ (β = .174, p < .001, sr2 = .02); pre-study emotions (β = .129, p < .001,

sr2 = .02); and, perceived threat (β = .266, p < .001, sr2 = .05). These results indicate

that females are more likely to report a post-event influence than males. Also, higher

levels of pre-study negative emotions and perceived threat were associated with a

greater likelihood of a post-event influence. Perceived threat uniquely contributed a

greater proportion of the variance than the other two variables.


related, emotional, cognitive and behavioural response variables on the likelihood of a

post-event influence to Scenario One (n = 926)

Variables

M

SD

B Std.

Error β

sr2

Adj R2

∆R2

Block One

Age1 40.5 19.6 .000 .001 .002

Gender .128** .048 .085 .01 Education Level2 -.004 .062 -.002 .07*** Block Two

Total AQ 47 15.6 .008*** .002 .174 .02

NPO 5.2 .52 .104* .049 .074 .00 ICS 5.2 .54 .014 .044 .010 RPS 3.3 .87 .007 .025 .009 .16*** .09*** Block Three

Pre-study Emotion

2 .77 .124*** .032 .129 .01

.18*** .02*** Block Four

Negative Emotions (S1) 2.5 1.1 .030 .029 .043

Perceived Threat (S1) 2.5 1.3 .149*** .019 .266 .05 Negative Attributions (S1)

2.1 1.1 -.046* .022 -.071 .00

.24*** .06*** Block Five

Likelihood of Instrumental Behavioural Response (S1)

3 1.1 .046 .041 .047

Likelihood of Hostile Behavioural Response (S1)

3.4

1.2

.047

.068

.022




related, emotional, cognitive and likelihood of behavioural response variables on the

likelihood of a post-event influence to Scenario Two (n = 926)

Variables

M

SD

B

Std. Error

β

sr2

Adj R2

∆R2

Block One Age1

40.5

19.6

.001

.001

.037

Gender

.075**

.036

.066

.00

Education Level2

.043

.047

.029

.03*** Block Two Total AQ

47

15.6

.003

.002

.078

NPO

5.2

.52

.083*

.037

.079

.00

ICS

5.2

.54

.047

.034

.046

RPS

3.3

.87

.015

.019

.024

.11*** .08*** Block Three Pre-study Emotion

2

.77

.034

.025

.047

.11*** .00 Block Four Negative Emotions (S2)

2.5

1.1

.026

.023

.052


1.9

.52

.217***

.035

.203

.03


2.1

1.1

.036

.020

.073

.19*** .08*** Block Five Likelihood of Instrumental Behavioural Response (S2)

3

1.1

.060

.035

.080

Likelihood of Hostile Behavioural Response (S2)

3.4

1.2

.216***

.062

.116

.01

.21*** .02*** 1. Age variable transformed to reflect midpoints of original categories. 2. Education level was recoded into a dichotomous variable. *** p < .001 ** p < .01 * p < .05

Similarly, in the regression of Scenario Two data (Table 5.26) there were only

two significant predictors of the likelihood of a post-event influence worthy of mention.


Perceived threat accounted for a significant proportion of the variance (β = .203, p <

.001, sr2 = .03), as did the likelihood of a hostile behavioural response (β = .116, p <

.001, sr2 = .01). Overall, the Scenario Two results indicate those more likely to perceive

threat and/or engage in hostile on-road behaviours in response to this scenario are more

likely to experience a post-event influence. Again, there was a lot of unexplained

variance.

5.3.8 Exploratory Analyses of Potentially Hostile Aggressive Drivers

5.3.8.1 Rationale

Using the available data, the researcher also endeavoured to explore the

characteristics of those participants who indicated a preparedness to engage in a hostile

aggressive response to the scenarios. For the purposes of these analyses these

participants are referred to as ‘potentially hostile aggressive’ (PHA) drivers.

5.3.8.2 PHA Driver Selection

In order to later explore the characteristics of the driver that has the potential for

more hostile aggressive acts on the road, participants with a mean score greater than

‘one’ on the three hostile aggressive behavioural response items in response to either

Scenario One or Two were distinguished (n = 88) from the larger sample (n = 926). An

average score of greater than one on these three items for either scenario was interpreted

as indicating that a participant was, to some degree, prepared to adopt more extreme

behaviours in response to a potentially anger-provoking on-road incident. Specifically,

these participants indicated their preparedness to engage in:

8. Stopping their vehicle and getting out ready to argue;

9. Stopping their vehicle and getting out ready to engage physically with the other

driver; and/or

10. Using their vehicle to physically damage the other driver’s vehicle.

The age and gender breakdown of the 88 drivers identified as PHA drivers is

presented at Table 5.27.


Table 5.27 Breakdown of gender by age group for the PHA driver group (n = 88)

Gender 17-24 years 25-39 years 40-59 years 60 + years Male 24 5 23 4

Female 18 4 6 4

TOTAL 42 9 29 8

5.3.8.3 Socio-demographic and Driving Characteristics of the PHA Drivers

A significant difference was found between the two driver groups in terms of age

[χ2 (df3)=16.157, p < .001, øc=.13] (refer to Table L1). Drivers aged 17–24 years were

proportionately more likely to be categorised PHA drivers (47.7%) than ‘other drivers’

(34.6%) [ê = 1.8, p < .05]. Not surprisingly, drivers 60 years and older were

significantly more represented in the ‘other driver’ group (23.4%), than the PHA driver

group (9.1%) [ê = 3.1, p < .005]. There was also a significant gender difference

between the PHA driver and ‘other driver’ groups [χ2 (df1) = 24.361, p < .001, ø = .162]

(refer to Table L2). Males were significantly more represented in the PHA driver group

(63.6%) than the ‘other driver’ group (36.6%) [ê = 4.9, p < .001].

Although a significant overall difference in the level of education attained by

PHA drivers and other drivers was detected [χ2 (df3) = 12.672, p < .01, øc = .117], none

of the comparisons at each level of the variable was significant at p < .01 (see Table L3).

However, examination of the frequencies in the cells indicates that a large proportion of

PHA drivers (92%) had attained a Year 12 or higher education (i.e. either senior –

39.8%, TAFE or apprenticeship – 31.8%, or university – 18%).

Participants were asked to indicate the approximate number of hours they drive

per week in the categories outlined at Table L4. As can be seen, there were no

significant differences found between the two driver groups in the number of hours

driven per week [χ2 (df4) = 5.583, p > .01, øc = .08].

Participants were also asked to indicate what type of vehicle they drove. As

some of the obtained cell frequencies were less than 5, various categories were collapsed

together. Utility vehicles, small/large trucks and all 4WDs were combined to be known

as ‘4WD, utility or truck’. Finally, as the number of participants that indicated use of


either a motorcycle or a van/people mover/ mini-bus was less than 5, these items were

excluded from the analysis. Thus, the number of participant responses under

consideration was reduced to ‘other drivers’ (n = 807) and ‘PHA drivers’ (n = 83).

The overall difference between the two driver groups of ‘other drivers’ and PHA

drivers [p = .017] was approaching significance at the predetermined alpha level, p >

.01. Examination of the frequencies at Table L5 suggests that PHA drivers may tend to

drive a medium-size vehicle or larger.

The measure of the type of road most frequently used distinguished between

urban, city, highway and open road. As can be seen in Appendix F, this measure made

simultaneous reference to the density of traffic to which a driver is most frequently

exposed, as traffic density is known to vary with type of roads travelled. For example,

the number of cars using a city/town road understandably varies from the number using

a country road. The categories were collapsed to reflect a measure of light, medium and

heavy traffic density, irrespective of type of road (see Table L6). However, no

significant differences between PHA drivers and ‘other drivers’ were found in relation to

exposure to traffic density [χ2 (df2) = 2.574, p = .276, øc = .05]. Also, it is worth noting

that on the original scale, approximately half of the PHA driver group (n = 47 or 53.4%)

reported most frequently driving on city/town roads in medium density traffic.

5.3.8.4 PHA Driver Differences in Trait Characteristics

A series of independent sample, Mann-Whitney U t-tests was conducted (Table

L7) comparing hostile aggressive drivers to other drivers on the various trait

characteristics measured via the survey (see Appendix F). Comparisons were made

between the potentially ‘hostile aggressive driver’ (n = 88) scores and ‘other drivers’ (n

= 838) on the AQ (Buss & Perry, 1992) subscales: physical aggression, verbal

aggression, angry aggression and hostile aggression. The results of the tests indicated

that the PHA drivers scored significantly higher on all four AQ subscales, as well as the

total AQ scale, than the ‘other drivers’ (refer to Table L7).

Secondly, the PHA driver group was compared with other drivers on the three

SPSI-R subscales of interest in this study, i.e. negative problem solving (NPO),

impulsive/carelessness style (ICS) and rational problem solving (RPS) (refer to Table

L7). The Mann-Whitney U tests were significant for: NPO [ z = -2.882, p < .005]; and


ICS [z = -4.081, p < .001], with the PHA drivers having higher scores on both NPO and

ICS than ‘other drivers’. Although not statistically significant (p > .017), the PHA

drivers’ scores on rational problem solving were lower than the other drivers.

Finally, prior to completing the questionnaire participants were asked to indicate

their current stress, happiness and agitation levels. A total score of ‘pre-study emotion’

was subsequently calculated. A test comparing levels of pre-study emotion reported

prior to completion of the questionnaire between the PHA drivers and other drivers was

significant [z = -4.711, p < .001] (refer to Table L7). Interestingly, PHA drivers had an

average rank of 590.10, while other drivers had an average rank of 450.21, suggesting

that the PHA driver group may have higher levels of negative emotion than ‘other

drivers’ at any given point in time.

5.3.8.5 PHA Driver Self Reported Driving Behaviour and Behavioural Intentions

Examination of the frequencies for the PHA driver group across the original

response categories indicates that 21.6% (n = 19) of PHA drivers reported being

involved in one crash in the last three years (see Table L8). In a more thorough

breakdown of the nine PHA drivers involved in two or more crashes as outlined above,

four reported having had two crashes, three reported having three crashes and one

reported having been involved in four crashes in the past three years. Interestingly, one

of the PHA drivers reported having had eight crashes in the past three years. However, it

should be noted that there was no overall significant difference in the self-reported crash

involvement of the PHA drivers compared to the ‘other drivers’ (see Table L8).

Similar to the measure of crash involvement above, participants were asked to

indicate the number of speeding fines they had received in the past three years. To aid

interpretation of the data, the frequencies were collapsed into three categories (see Table

L9). Again, no significant difference was found between reported speeding fines for

other drivers and PHA drivers [χ2 (df2) = 1.927, p = .381, øc = .05]. Examination

revealed that 34% (n = 29) of the PHA driver group and 27.3% (n = 221) of other

drivers had received one or more speeding fines in the past three years (Table L9).

Participants also reported whether they had been fined for any other offences

during the last three years. As shown in Table L9, these responses were recoded into


two categories. No significant difference was found between PHA drivers and other

drivers on this variable [χ2 (df1) = 1.885, p = .170, ø = .048].

When asked to indicate the number of drink-driving charges they have had in the

last three years, a significant difference was found between the obtained frequencies of

drink-driving charges for the driver groups [χ2 (df1) = 7.951, p < .05, øc = .10] (see

Table L9). A significantly larger proportion of PHA drivers (4.1%) had reported one or

more drink-driving charges than the ‘other’ driver group (.7%). However, caution

should be exercised when interpreting these results as one of the cell frequencies was

below 5, potentially influencing the results.

Participants were also asked if they had driven unlicensed in the past three years.

Unfortunately, 120 participants chose not to respond to this question, while only four

reported engaging in such behaviour. Therefore, it was not possible to detect any

meaningful differences between the two driver groups.

The self-reported driving behaviour and behavioural intentions of the PHA and

‘other drivers’ were also compared using Mann-Whitney U Tests due to the skewed

distribution of participant responses to the four intention variables (refer to Table L10).

The PHA drivers reported significantly stronger intentions than other drivers in relation

to their preparedness to exceed the speed limit by 10km/h or more on urban roads [z =

2.993, p < .05] and on highways [z = 4.188, p < .001]. PHA drivers also indicated

significantly stronger intentions to drink drive and drug drive [z = 4.714, p < .001 and z

= 5.127, p < .001 respectively].

5.3.8.6 PHA Driver Emotional, Cognitive and Behavioural Responses

Using Mann-Whitney U tests, PHA drivers and other driver emotional, cognitive

and behavioural responses to each scenario were compared. The results of these tests

are outlined at Table L11. Considering five tests were conducted for each scenario a

Bonferoni adjustment was made (.05 ÷ 5) which resulted in the adoption of p < .01

value.

Significant differences were found between the driver groups on self-reported

negative emotions in response to both Scenarios One and Two [z = -3.509, p < .001 and

z = -3.973, p < .001]. PHA drivers reported higher scores in response to both Scenario

One and Scenario Two, than the ‘other drivers’.


As can be seen in Table L11, the comparison of PHA drivers and ‘other drivers’

on the likelihood of perceiving threat was significant for Scenario Two only [z = -5.725,

p < .001]. In this case, the PHA drivers reported a strong perception of threat than ‘other

drivers’ in an ambiguous, though potentially anger-provoking, scenario. The non-

significant result between PHA drivers and ‘other drivers’ on perceived threat in

response to Scenario One [z = -.319, p >.01] indicates that there was no difference

between drivers in their tendency to perceive threat in an anger-provoking on-road

situation.

Though the comparison of the driver groups for Scenario One negative

attributions was not significant [z = -2.353, p > .01], the difference between the average

ranks for PHA [526.98] and ‘other drivers’ [456.83] was in the direction anticipated.

The comparison of the PHA drivers and ‘other drivers’ on Scenario Two responses was

significant [z = -4.711, p < .001]. Again, PHA drivers had a higher negative cognition

score in response to Scenario One than ‘other drivers’.

As previously detailed, six items on the behavioural response scale were used to

calculate a total score reflecting the likelihood of an instrumental aggressive response

for each participant. Similarly, the three items detailing more severe behavioural

responses were used to calculate the likelihood of having a hostile reactive aggressive

response. Mann-Whitney U tests comparing the PHA drivers and the ‘other drivers’ on

the likelihood of an instrumental aggressive response was significant for both scenarios:

Scenario One [z = -9.164, p < .001]; and Scenario Two [z = -8.702, p < .001]. In both

scenarios the PHA driver group had higher average ranks [Scenario One – 711.19,

Scenario Two – 698.69] than ‘other drivers’, average rankings 437.49 and 438.80

respectively. As such, not only did the PHA driver group report a higher score for an

instrumental aggressive response to an anger-provoking incident (Scenario One), but

also when the on-road incident is ambiguous (Scenario Two).

Mann-Whitney U tests also compared self-reported likelihood of a post-event

influence following an on-road incident between PHA drivers and ‘other drivers’

following Scenarios One and Two. Both tests were significant, Scenario One – z = -

3.695, p < .001 and Scenario Two – z = -3.362, p < .001. In response to Scenario One,

the PHA drivers [average rank = 556.91] were more likely to report stronger post event


influence than the ‘other drivers’ [average rank = 453.69]. This result was also reflected

in response to Scenario Two. That is, hostile aggressive drivers [average rank = 535.00]

were more likely to report a stronger post event influence following an ambiguous on-

road incident than the ‘other drivers’ in the sample [average rank = 455.99].

5.3.8.7 Ability of Variables to Predict PHA Driver Group Membership

The final step in the analysis of Study Two data was to assess the extent to which

the various discrete and continuous variables of the proposed model of aggressive

driving predict PHA group membership. Consequently, a logistic regression was

conducted utilising the person-related, emotional, cognitive and behavioural responses

and individual driving exposure variables as predictor variables (refer to Table L12).

Person-related predictors were gender, age (17–24 years, 25–39 years, 40–59 years and

60 years plus), trait aggression (as measured by the AQ), social problem solving

subscale score measures (NPO, ICS and RPS scores), pre-study emotions and education

(either < Year 10 or > Year 10). The emotional, cognitive and behavioural response

predictor variables were the total negative emotions, perceived threat, negative

cognitions and likelihood of an instrumental aggressive reaction, summed across the two

scenarios.

The majority of these variables are continuous and missing values were replaced

with the mean. Ninety-two cases with missing values on the categorical variables, age,

hours driven per week, type of vehicle and congestion exposure, were excluded from

analysis leaving 834 drivers for the analysis. There was no identifiable pattern to the

missing data.

A test of the full model with all predictors against a constant-only model was

statistically reliable [χ2 (df24, n = 834) = 170.99, p < .001, Nagalkerke R2 = .41]. The

predictors as a set reliably distinguished between PHA drivers and other drivers.

However, prediction of PHA group membership was relatively poor, with only 29.3% of

PHA drivers correctly predicted. Conversely, 98.4% of ‘other drivers’ were correctly

predicted. The overall prediction success rate was 91%.

As shown in Table L12, three person-related predictors, three emotional,

cognitive and behavioural response predictors and one of the driving exposure predictors

reliably predicted driver group membership. Gender [B = -1.04, p < .01, odds ratio =


.36, CI = .18 - .70] and total AQ scores [B = .04, p < .01, odds ratio = 1.04, CI = 1.01 –

1.06] were significant predictors. The gender indices indicate that being female

increases the likelihood of ‘other driver’ group membership, whilst the total AQ indices

suggest that higher trait aggression scores increase the likelihood of PHA group

membership. The categorical, person-related variable ‘age’ also yielded a significant

result for 25–39-year-old drivers [B = -1.13, p < .05, odds ratio = .32, CI = .12 – 1.07].

These indices indicate that drivers aged 25–39 years old are more likely to belong to the

‘other driver’ group. However, this could be a product of the fact that proportionately

less 25–39 year-old drivers were recruited than other age groups.

The three response predictors were negative emotions [B = -.83, p < .01, odds

ratio = .44, CI = .25 - .76], perceived threat [B = .32, p < .01, odds ratio = 1.37, CI =

1.09 – 1.73] and instrumental aggressive behavioural response [B = 2.08, p < .01, odds

ratio = 7.99, CI = 4.2 – 14.9]. These results indicate that greater negative emotions

and/or lower levels of perceived threat experienced by a driver increase the likelihood of

belonging to the PHA driver group. Finally, being more likely to engage in instrumental

aggressive behaviours rather than hostile behaviours increased the likelihood of

belonging to the ‘other driver’ group.

Of the categorical driving exposure variables, ‘type of vehicle’ yielded

significant results at p < .05:

• Medium vehicle – [B = 1.02, odds ratio = 2.78, CI = 1.18 – 6.53]

• Large vehicle – [B = 1.18, odds ratio = 3.25, CI = 1.18 – 8.96]

• Four Wheel Drive – [B = 1.39, odds ratio = 4.0, CI = 1.31 – 12.2]

These results indicate that drivers of medium/large vehicles and four wheel

drives are more likely to be categorised as PHA drivers than drivers of small vehicles

(i.e. reference group).

5.4 Discussion

The following section discusses the results of the study in terms of the relevant

research questions and specific hypotheses outlined in Section 5.1.1.


5.4.1 Response Differences to On-Road Scenarios


driving?

H1 Drivers will report stronger emotional, cognitive and behavioural

responses and post-event influence in response to a clearly anger-

provoking incident than to an ambiguous incident.

In support of Hypothesis One, the pairwise t-test results at Table 5.12 (Section

5.3.6.1) suggest that drivers, in general, do respond differently to an intentionally anger-

provoking on-road incident as opposed to an ambiguous, though potentially anger-

provoking, on-road incident. Participants reported significantly greater levels of each of

the following factors in response to Scenario One (p < .001): negative emotion, feelings

of threat, likelihood of negative attributions, likelihood of instrumental and/or hostile

aggression and likelihood of post-event influence in response to an intentionally anger-

provoking incident than in response to Scenario Two (ambiguous incident). Although

there was a significant difference between Scenarios One and Two in the likelihood of a

hostile aggressive behavioural response (p < .025), the difference between the means

was extremely small and there is evidence of a moderate-strong relationship between

hostile aggressive responses between Scenarios One and Two (r = .58, p < .001) (refer to

Table 5.14). This suggests that those more likely to respond with hostile aggression to

Scenario One were more likely to adopt this type of behavioural response to Scenario

Two.

In aggressive driving research there is considerable support for the above

findings concerning stronger levels of negative emotions being reported in response to

on-road incidents that are anger-provoking, and subsequently culminating in the

increased likelihood of aggressive behavioural responses (O’Brien, Watson, & Tay,

2005; Lajunen & Parker, 2001; Shinar, 1998). The results of these t-tests are also

consistent with Frustration-Aggression theory (Dollard et al., 1939) and GAM theory

(Andersen & Bushman, 2001), both of which propose that stronger feelings of

frustration/anger increase the likelihood of an aggressive behavioural response.

The results relating to significantly stronger levels of ‘threat’ being reported in

response to Scenario One and resulting in an increased likelihood of an instrumental or


hostile behavioural response, are consistent with human aggression research (Anderson

et al., 1998; Berkowitz, 1989, 1990; Dodge & Coie, 1987). For instance, Berkowitz

(1989, 1990) maintained that ‘fear’ is a basic instinctive response to a provocative

incident that will result in ‘flight’ or ‘fight’. This finding also lends support to the Study

One findings in which young drivers cited feelings of ‘dangerousness’, and/or more

explicitly ‘fear’, as a result of an on-road incident. Consequently, these findings also

support the inclusion of ‘threat’ in the theoretical model of aggressive driving behaviour

(see Figure 4.3) as a legitimate contributing factor to on-road aggression.

The findings concerning the increased likelihood of having negative attributions

associated with such an incident, are also consistent with the human aggression theories

incorporated in the GAM (Anderson & Bushman, 2002. The GAM emphasises the

interplay between emotions and cognitions in response to environmental stimuli; in this

instance, an on-road incident. These results are further supported by subsequent results

involving either an instrumental or hostile behavioural response, whereby participants

reported an increased likelihood of either type of behavioural response in the face of a

clearly anger-provoking incident. From the literature review of aggression theory,

negative cognitions are frequently associated with reactive aggressive responses

(Anderson & Bushman, 2002; Berkowitz, 1989; Deffenbacher et al., 2003; Dollard et

al., 1939).

Finally, consistent with previous research into displaced aggression (Lawton &

Nutter, 2002; Marcus-Newhall et al., 2000; Pedersen et al., 2000), the results of the

pair-wise t-tests suggest there is an increased likelihood of a post-event effect having

been confronted with an intentionally provocative incident, compared with an

ambiguous one. Specifically, consideration of the items presented to participants

indicated an increased likelihood of the incident influencing subsequent on-road

behaviours, in other tasks performance and/or in their dealings with others. Therefore, it

appears there is evidence to support the potential for an anger-provoking on-road

incident to generate sufficient emotion to transfer to the on and off-road environment.

Although it should be noted that the relatively small effect size may be due to

participants responding to ‘artificial’ on-road scenarios and the effect in real-life may be

greater.


Furthermore, it should be acknowledged that there are two areas of the GAM that

were not assessed in this study due to the use of scenarios and their lack of realism.

Firstly, this study was not able to measure physiological arousal levels that a driver may

bring to the on-road environment, suggested as important to aggressive behavioural

outcomes in the GAM (Anderson & Bushman, 2001). Secondly, the decision-making

process as strictly outlined in the original GAM was not fully explored. The decision

not to explore this process fully was based on Study One findings that suggested many

of the decisions associated with aggressive driving behaviour are performed at a

subconscious level. Additionally, the participants were not physically situated in the

driving environment at the time of their responses and, therefore, would not be subject to

the ‘real-life’ temporal and environmental constraints.

5.4.2 Exploration of the Components of the Proposed Theoretical Framework of

Aggressive Driving

The results are discussed in keeping with the hypotheses formulated according to

the three stage exploration of the proposed theoretical framework derived from the

GAM, detailed at Figure 5.1.

H2 Driving exposure factors such as type of vehicle driven, congestion

exposure and hours driven per week will be associated with driver


Only partial support was found for H2. Though significant correlations were

found between several of the driving exposure variables and the behavioural outcomes

(refer Table 5.14), the strength of these relationships were small, falling below r = .2.

As a result, none of the driving exposure variables were included in the regression

analyses. Despite this, some of the significant correlations are worth noting.

Examination of the correlations revealed that smaller vehicles are driven by those

who experience greater levels of negative emotion (r = -.11, p < .001) and perceived

threat (r = -.11, p < .001) in response to Scenario One. Smaller vehicles were also found

to be significantly associated with hostile aggressive responses to Scenario One (r = -

.08, p < .05) and an increased likelihood of a post-event influence (r = -.10, p < .001).

These findings are contrary to the Study One findings that suggested that aggressive

drivers are more likely to drive larger or modified vehicles. However, it should be noted


that these results may be the product of the large and diverse sample surveyed for the

purpose of this study. In other words, the survey did not specifically target hostile

aggressive drivers, rather it was aimed at a cross-section of the general driving

population. Alternatively, the greater proportion of young drivers surveyed may have

influenced the results, given that young drivers in general tend to drive smaller, possibly

more affordable vehicles.

H3 Socio-Demographic factors will be significant predictors of emotional,

cognitive and behavioural responses to on-road provocation.

In each of the relevant multiple regressions, socio-demographic factors

contributed a significant proportion of the variance in the emotional, cognitive and

behavioural responses of the participants in support of H3. However, of the socio-

demographic factors included in the regression on self-reported negative emotions in

response to Scenarios One and Two, participant age was the only individually significant

predictor (S1 - β = .046, p < .001 and S2 - β = -.263, p < .001). As such, younger

drivers appear more likely to experience greater levels of negative emotion when faced

with either on-road situation, in keeping with earlier aggressive driving research that

found that younger drivers are more likely to experience greater levels of frustration or

anger in response to an on-road incident (Lajunen & Parker, 2001; O’Brien, Watson, &

Tay, 2004; Shinar, 1998). The regression analyses also indicate that driver gender

contributes little to the level of annoyance, frustration or anger experienced in response

to on-road provocation.

In contrast, gender was the only significant socio-demographic variable for self-

reported feelings of ‘threat’ in response to Scenario One (β = .238, p < .001, sr2 = .05).

Therefore, it would seem that females are more likely to report feeling threatened in

response to more clearly provocative on-road incidents. This is consistent with Study

One findings that found that females were more likely to report experiencing fear and

feelings of intimidation when faced with a provocative on-road incident. None of the

socio-demographic variables were found to be individually significant predictors of

perceived threat in response to Scenario Two. However, there was some evidence of a

significant association between age and perceived threat in response to this scenario (r =

-.13, p < .001), suggesting that younger drivers may perceive greater threat in an


ambiguous, yet anger-provoking scenario. This relationship may be indicative of their

relative inexperience with the driving environment.

In regard to the likelihood of experiencing negative attributions, age was found

to be a significant predictor in the case of Scenario One (β = -.172, p < .001, sr2 = .02),

whilst both age and gender were found to be significant predictors in the case of

Scenario Two (age - β = -.129, p < .001, and gender - β = -.106, p < .001). In both

scenarios, as age increases the likelihood of experiencing negative attributions appears

to decrease. This finding is consistent with Study One findings that found a substantial

number of young drivers in the sample (n = 28) reported having negative thoughts about

the ‘other driver’. In response to the ambiguous situation in Scenario Two, however,

males were found to be significantly more likely to experience negative attributions than

females.

The foregoing results confirm earlier aggressive driving research (Lennon,

Watson, Arlidge, & Fraine, under review; Yagil, 2001). As outlined above in Section

5.3.5.3, younger drivers (17–24 years of age) have higher levels of trait aggression.

They are also more likely to experience greater levels of anger and frustration in

response to a potentially anger-provoking incident. Consequently, the results suggest

they are more likely to have negative attributions about the behaviour of other road users

(Lennon, Watson, Arlidge, & Fraine, under review; Yagil, 2001). These findings also

emphasise the findings of general aggression research that acknowledges the interplay of

intense negative emotions and activation of negative thoughts, potentially increasing the

likelihood of aggressive behaviour (Berkowitz 1988, 1989).

In further support of H3, the regression analyses on the likelihood of adopting

instrumental behaviours in response to Scenarios One and Two, revealed that socio-

demographic factors contributed a significant proportion of the variance (S1 – R2 = .19,

and S2 - R2 = .20). Although participant age was found to be the only individually

significant predictor (p < .05) in response to either scenario, the small semi-partial

correlations revealed that it accounted for very little of the variance. The trend that

younger drivers are more likely to adopt instrumental aggression is, however, consistent

with other aggressive driving research and Study One findings (Harding et al., 1998;

Lajunen et al., 1999; Shinar, 1998; VCCAV, 1999). Also consistent with Study One


findings, gender was not found to be a significant predictor for adopting an instrumental

behavioural response, contrary to the same research that simultaneously reported that

males will be more likely to adopt such behaviours on the roads (Harding et al., 1998;

Lajunen & Parker, 1998; Shinar, 1998; VCCAV, 1999).

The education level attained by participants was also found to be a significant

predictor, but it only accounted for a minimal amount of variance. In this instance, those

drivers with a Year 10 education or better were more likely to adopt an instrumentally

aggressive response. This finding is contrary to human aggression research which has

long associated lower levels of education with greater levels of human aggression and

road safety research (Harris et al., 1996a; Murray, 1998; Shinar, Schechtman, &

Compton, 2001). This contrary result could be due, in part, to a societal trend to pursue

greater than a Year 10 education. Alternatively, it may be due to the nature of

aggressive driving behaviour itself. Perhaps, the anonymity experienced whilst driving

(Ellison, Govern, Herbert, & Figler, 1995) allows a greater range of individuals, with a

wider range of educational achievements, to adopt an instrumental aggressive response

to on-road provocation.

H4 Trait aggression will be a significant predictor of emotional, cognitive and

behavioural responses to on-road provocation.

H5 Higher levels of ICS and NPO and lower levels of RPS will be predictive

of emotional, cognitive and behavioural responses to on-road

provocation.

The trait person-related variables of interest significantly contributed to the

prediction of negative emotions reported by participants in response to both scenarios

(S1 - R2 = .08, and S2 - R2 = .11), having controlled for socio-demographic variables,

lending support for H4 and H5. Total AQ scores and NPO were both individually

significant predictors of negative emotions in response to both scenarios (S1 - AQ, β =

.204, p < .001, sr2 = .02, and NPO - β = .139, p < .001, sr2 = .01; S2 - AQ, β = .271, p

< .001, sr2 = .04, and NPO - β = .141, p < .001, sr2 = .01). These results indicate that as

trait aggression and negative problem orientation increase so do the negative emotions

experienced as a result of exposure to provocative on-road incidents consistent with

other aggressive driving research (Buss & Perry, 1992; D’Zurilla, Nezu, & Maydeu-


Olivares, 2002; D’Zurilla et al., 2000; Lajunen & Parker, 2001). Examination of the

semi-partial correlations would indicate that trait aggression accounted for more of the

unique variance in the case of Scenario Two than Scenario One. This finding is

indirectly supported by the research of Dodge and colleague (1987) that found that

aggressive children are more likely to experience anger in response to ambiguity in

social situations.

In regard to levels of ‘perceived threat’, trait person-related factors also

contributed a significant proportion of the variance (S1 - R2 = .05, and S2 - R2 = .05). In

response to Scenario One, NPO was the only predictor to contribute a significant

proportion of the variance (β = 212, p < .001, sr2 = .03), higher levels of negative

problem orientation increasing the likelihood of perceiving threat in an anger-provoking

scenario. In contrast, both total AQ and NPO were individually significant predictors of

perceived threat in response to Scenario Two (AQ, β = .126, p < .001, sr2 = .01, and

NPO - β = .155, p < .001, sr2 = .02). This result indicates that those individuals high on

trait aggression and/or negative problem orientation are more likely to feel threatened in

an ambiguous on-road incident. Other human aggression research suggests that many

individuals with aggression difficulties have, at some point in their lives, been exposed

to environmental/developmental stimuli that have served to increase their trait

aggression levels (refer to Section 3.2) (Anderson et al., 1998; Dodge & Coie, 1987;

Silva & Marks, 2001). This research proposes that such exposure has the potential to

predispose some individuals to the adoption of ‘anger’ and the detection of ‘threat’

within ambiguous situations.

Further, the regression analyses on negative attributions revealed that trait

person-related factors again contributed to a significant amount of the variation (S1 - R2

= .04, and S2 - R2 = .08). However, trait aggression was the only significant trait

predictor variable of negative attributions in response to Scenario One (β = .217, p <

.001, sr2 = .03). Conversely, for Scenario Two, trait aggression (β = .258, p < .001, sr2 =

.04), NPO (β = .084, p < .05, sr2 = .01) and RPS (β =-.075, p < .05, sr2 = .01) were

found to be individually significant predictors. In response to either scenario, these

results indicate that higher trait aggression levels are predictive of an increased

likelihood of negative attributions in the face of on-road provocation, consistent with


human aggression research (Dodge & Coie, 1987). Additionally, greater NPO levels are

also significantly predictive of more negative attributions in response to an ambiguous

on-road situation such as Scenario Two. This latter result may be considered consistent

with the human aggression research that has found a relationship between depression

and greater levels of irritability (Stanford et al., 1995), cognitive negativity being highly

related to depression (Caprara et al., 1987; Bushman et al., 2005).

Finally, as may have been anticipated by the human aggression and problem-

solving research (D’Zurilla, Nezu, & Maydeu-Olivares, 2002), lower levels of RPS were

also predictive of negative attributions in response to this scenario. The previous

research found that ICS and NPO are more highly related to the adoption of aggressive

behaviours (D’Zurilla, Nezu, & Maydeu-Olivares, 2002). Collectively, these results

would suggest that when faced with situational ambiguity, individuals with higher levels

of trait aggression, lower levels of rational problem-solving skills and/or those with

higher levels of negative problem-solving orientation will have a tendency to interpret

the driving behaviour of others in a more negative manner.

It is also worth noting, that trait person-related factors were also found to

contribute a significant amount of the variance in the likelihood of adopting instrumental

aggression in response to both Scenarios One and Two (S1 - R2Change = .18 and S2 -

R2Change = .19). In response to Scenario One, trait aggression levels (β = .345, p < .001,

sr2 = .06), NPO (β = -.079, p < .05, sr2 = .00) and ICS (β = .088, p < .001, sr2 = .01)

were identified as significant predictors lending support for H4 and H5. In contrast, trait

aggression (β = .320, p < .001, sr2 = .05) was the only significant trait person-related

predictor in the case of Scenario Two. In response to both scenarios, higher trait

aggression scores were predictive of a likelihood of adopting instrumental aggression.

Furthermore, those drivers with higher levels of impulsive/careless problem-

solving style were also more likely to adopt instrumental behaviour in response to

Scenario One, consistent with other research into impulsivity and driving behaviours

(Eysenck et al., 1995; Dahlen et al., 2005; Deffenbacher et al., 2000; Karli, 1991).

Additionally, in response to Scenario One, lower levels of NPO were associated with a

greater likelihood of adopting an instrumental response. Upon reflection, these results

may suggest that those individuals that have less negative problem orientation and/or a


tendency to respond to provocation in an impulsive or careless manner, will be more

likely to adopt an instrumental behavioural response to Scenario One.

H6 Pre-study emotions as a measure of state person-related stress will be

predictive of emotional, cognitive and behavioural responses to on-road

provocation.

Some support was found for H6. In the final set of regression analyses, pre-

study emotions, as a measure of state stress, were found to account for a significant,

though small, proportion of the variance in negative emotions reported in response to

Scenarios One and Two (S1 - R2 change = .01 and S2 - R2 change = .01). The results

indicate that off-road generated emotions may have the potential to influence on-road

emotional, cognitive and behavioural responses. That is, off-road generated emotion

will increase the likelihood of experiencing negative emotions when faced with a

provocative incident. Alternatively, they may indicate that pre-study emotions as a

measure of state stress may influence the negative emotions reported by participants in

surveys, albeit to a small degree.

Pre-study emotion was also found to be a significant predictor of ‘perceived

threat’ in response to Scenario One (β = -.082, p < .001, sr2 = .01). As previous research

suggests, greater levels of frustration/anger or negativity brought to the on-road

environment may increase the likelihood of detecting threat in a subsequent anger-

provoking on-road incident (Anderson et al., 1998; Dodge & Coie, 1987; Novaco et al.,

1990; Silva & Marks, 2001). Interestingly, it was not predictive of the likelihood of

negative attributions made in response to either scenario, contrary to the potential for

higher levels of negative emotions to contribute to the adoption of more negative

attributions (Berkowitz, 1983, Geen & Donnerstein, 1998; Lajunen & Parker, 2001).

However, it should be noted that these feelings are independent of the anger-provoking

situation and therefore temporally and situationally unrelated to the measure of the

emotional and cognitive response variables. As such, it appears that the temporal

differences may account for the lack of a relationship between pre-study emotions and

attributions.

In contrast, pre-study emotions did not significantly add to the prediction of the

likelihood of either instrumental or hostile aggression in response to Scenarios One and


Two. Given that the prior contribution of pre-study emotions to other dependent

variables has been relatively small this result is not overly surprising. Conversely, it

may also be a product of the artificiality of the use of scenarios.

H7 Higher levels of negative emotion, perceived threat and negative

attributions will predict the likelihood of stronger instrumental and hostile

aggressive behavioural responses to on-road provocation.

In response to both scenarios, emotional and cognitive response variables added

significantly to the likelihood of adopting instrumental aggression (S1 - R2Change = .12

and S2 - R2Change = .17) in general support of H7. Participant self-reported negative

emotions (β = .356, sr2 = .07), perceived threat (β = -.091, sr2 = .01) and negative

attributions (β = .114, sr2 = .01) were significant predictors of the likelihood of adopting

instrumental aggression in response to Scenario One. Similarly, negative emotions (β =

.318, sr2 = .05) and negative attributions (β = .229, sr2 = .03), but not perceived threat,

were predictive of instrumental aggression in response to Scenario Two. As such, the

results indicated that higher levels of negative emotion accounted for a greater

proportion of the variance in the prediction of the likelihood of instrumental aggression

than the other emotional and cognitive response variables consistent with other human

aggression and traffic psychology research (Berkowitz, 1989, 1993; Lajunen & Parker,

2001; Shinar, 1998). Further to this, higher negative attributions were more predictive

of an instrumentally aggressive response in the ambiguous anger-provoking situation.

Overall, the contribution of emotional and cognitive responses to the likelihood

of instrumental aggression is consistent with GAM theory and other human aggression

research (Anderson & Bushman, 2002; Berkowitz, 1989; Dollard et al., 1939; Shinar,

1998). In keeping with this research, higher levels of negative emotions and a greater

likelihood of negative attributions do appear to contribute to the likelihood of adopting

an instrumental response. In addition, these results also support the proposition by

Berkowitz (1989) that negative emotions and negative schemas are linked in a cognitive

manner and will increase the likelihood of an aggressive response.

As previously noted, in the regression analyses examining the likelihood of a

hostile aggressive response to Scenario One, socio-demographic variables (R2 = .02)

collectively contributed significantly to the prediction of hostile aggressive behaviour, in


support of H3. Consistent with H4 and H5, two trait person-related variables (R2change =

.11) were identified as individually significant predictors of the likelihood of a hostile

aggressive behavioural response: trait aggression (β = .369, sr2 = .07), and ICS (β =

.102, sr2 = .01). In this intentionally anger-provoking scenario, those drivers higher on

trait aggression and/or impulsive/careless problem solving appear more likely to engage

in hostile on-road aggressive behaviours, similar to the results for the likelihood of

adopting instrumental on-road behaviours. Though the proportion of variance explained

by ICS is small, these results are consistent with human aggression and traffic

psychology research that has found high levels of impulsivity associated with young

males and their driving behaviour (Eysenck et al., 1995; Connor et al., 2003; Dahlen et

al., 2005; Deffenbacher et al., 2003b; Karli, 1991).

Interestingly, however, the emotional and cognitive response variables were not

significant predictors of the likelihood of a hostile aggressive response to Scenario One

(see Table 5.23). The adoption of hostile aggressive behaviours to this intentionally

anger-provoking scenario, therefore, appears to be contingent on the trait characteristics

of the driver, indicating a lack of support for H7.

In contrast, in response to Scenario Two, although the socio-demographic

variables contributed a significant proportion of the variance in the likelihood of a

hostile behavioural response (R2 = .01), the trait person-related factors (R2 change = .04)

and cognitive and emotional response factors (R2 change = .10) also contributed

significantly to the variance. Of these variables, total AQ (β = .178, sr2 = .02), negative

emotions (β = -.169, sr2 = .01) and perceived threat (β = .321, sr2 = .09) were

individually significant predictors of the likelihood of hostile aggression in response to

Scenario Two.

H8 Higher levels of negative emotion, perceived threat, negative attributions

and an increased reporting of a behavioural response to on-road

provocation will increase the likelihood of a post-event influence being

experienced.

The regression analyses relating to the likelihood of a post-event influence

following Scenarios One and Two were both significant (S1 – Adj R2 = .24, and S2 –

Adj R2 = .21). However, the results are complex and show mixed support for H8.


Before discussing the influence of the emotional, cognitive and behavioural response

variables on the likelihood of a post-event influence, it is worth noting the impact of the

socio-demographic factors and pre-study emotions on this outcome.

In response to Scenario One, female drivers were significantly (p < .001) more

likely to report a post-event influence (β = .085, sr2 = .01). In response to the more

ambiguous situation posed by Scenario Two, females were again more likely to

experience a post-event influence (β = .066, sr2 = .00), however, the semi-partial

correlation indicates gender contributes only a minimal amount of the variance. Trait

person-related factors contribute a significant amount of variance having controlled for

the socio-demographic variables in response to both scenarios (S1 - R2 change = .09 and

S2 - R2 change = .08). Specifically, trait aggression (β = .174, sr2 = .02) and NPO (β =

.074, sr2 = .00) was identified as a significant predictor of a post-event influence in

response to Scenario One. However, in response to Scenario Two, NPO (β = .079, sr2 =

.00) was the only significant person-related predictor variable. As such, those high on

trait aggression and negative problem-solving style appear more likely to experience a

post-event influence. Perhaps this effect is due to the potential for aggressive or

negative individuals to ruminate about a provocative incident, as suggested in human

aggression research concerned with emotional susceptibility, ruminating and aggression

(Caprara et al., 1987; Bushman et al., 2005).

Pre-study emotions, as a measure of state factors, were also found to be

predictive of the likelihood of a post-event influence in response to Scenario One (β =

.129, sr2 = .01) (Novaco et al., 1990; Matthews et al., 1991; Parkinson, 2001).

However, the state person-related variable, pre-study emotions did not contribute to the

overall prediction of a post-event influence in response to Scenario Two.

Turning to the influence of the emotional and cognitive responses on the

likelihood of a post-event influence, in Scenario One they contributed a significant

proportion of the variance (R2 change = .06) having controlled for socio-demographic, trait

and state person-related variables. Of these variables, perceived threat (β = .266, sr2 =

.05) was the only notable significant predictor of a post-event influence. As such, it

would appear that feelings of threat appear to persist longer than other negative

emotions, thereby having the potential to influence subsequent interactions.


In contrast, the emotional, cognitive and behavioural response variables did

contribute a significant proportion of the variance to post-event influence in response to

Scenario Two (R2 change = .08 and R2 change = .02 respectively). Again, higher levels of

perceived threat were found to be a significant predictor variable of post-event influence

(β = .203, sr2 = .03). As such, this result clearly demonstrates that feeling threatened

when faced with an ambiguous on-road situation increases the likelihood of

experiencing a post-event influence. Considering the items contained in the post-event

measure, the result suggests that drivers may be influenced on the remainder of their

journey, whilst conducting other tasks during the day or in their dealings with others.

The likelihood of adopting either an instrumental or hostile behavioural response,

however, was not predictive of a possible post-event influence in response to the

intentionally anger-provoking scenario portrayed in Scenario One. This finding may be

suggestive that expression of either instrumental or hostile behaviours may serve to

reduce any residual thoughts or emotions associated with such an on-road situation,

consistent with the cathartic effect first mentioned in frustration-aggression theory

(Dollard et al., 1939). However, this concept would require much closer examination

before definite findings would be reportable.

A greater likelihood of adopting a hostile aggressive behavioural response was

minimally predictive of a likelihood of a post-event influence (β = .116, sr2 = .01) in

response to Scenario Two. This finding suggests that perhaps the expression of hostile

aggressive behaviours in response to an ambiguous on-road situation does not

necessarily have a cathartic effect for some drivers. As noted above, human aggression

research would suggest the outward expression of aggression has a cathartic effect,

allowing the frustration-aggression threshold to return to its ‘normal’ state (Dollard et

al., 1939). However, it would seem that for some drivers, the adoption of hostile

aggressive behavioural responses may increase the time-lapse required to return to the

‘normal’ state, exposing some individuals to the potential for residual effects.

Notably, the results of the regression analyses indicate that there was a

considerable amount of unexplained variance. Perhaps this was due to the artificiality of

the methodology. Alternatively, perhaps it is due to the limited number of variables that

were operationalised in order to examine the theoretical framework at Figure 5.1, as it is


well-known that a large range of variables have the potential to negatively influence on-

road behaviour (refer to Figure 2.1 for example).

5.4.3 The Nature and Purpose of Aggressive Driving Behaviours

The results of Study Two show considerable support for Hypothesis Nine:

H9 The response of drivers to an intentionally provocative on-road incident

can be categorised into two distinct but related types of behaviours,

instrumental or hostile, which serve different functions for drivers.

Consistent with the research of Shinar (1998) and Lajunen & Parker (2001),

factor analysis of the behavioural response items indicated two distinct types of

behavioural responses. As detailed in Section 5.3.3.3 (Table 5.8), the behaviours

labelled ‘instrumental aggression’, can be adopted with little or no loss of time or

without deviating from the original goal of driving. As such, the adoption of

‘instrumental’ on-road aggression appears to facilitate one’s journey. Alternatively,

those behaviours labelled ‘hostile aggressive’ were more extreme in nature, sometimes

involving interpersonal violence. These behaviours reflected a preparedness to deviate

from one’s original reason or goal for driving, investing the ‘time’ to personally express

anger or annoyance. Therefore, the function served by ‘hostile’ behaviours appears to

be personally, and intrinsically, important to the driver, suggesting the strong

involvement of person-related characteristics as confirmed by the foregoing research.

Finally, the total average participant instrumental and hostile aggressive

behavioural responses were found to be significantly associated (r = .36, p < .001). This

was largely anticipated, due to the role of ‘aggression’ in the adoption of many of the

behaviours. However, it is only a moderate relationship, where 13% (r = .36) of the

total variance in the likelihood of adopting ‘hostile aggressive’ behaviour is predicted by

the likelihood of adopting ‘instrumental aggression’. In summary, it would appear that

the behaviours adopted in aggressive driving fall into two distinct but related categories,

serving different functions for the aggressor.

5.4.4 Exploration of the PHA Driver Findings

5.4.4.1 Socio-Demographic and Driving Characteristics of the PHA Driver

Utilising the four age groups identified in earlier analyses, a significant age

difference was found between the PHA drivers and other drivers (p < .001). Young


drivers are proportionately more likely to be categorised PHA drivers than other drivers

(Lajunen & Parker, 2001; Harding et al., 1998; O’Brien, Tay, & Watson 2005;

VCCAV, 1999). Conversely, older drivers (60 years and over) were more likely to fall

in the ‘other driver’ category and there was no significant difference between drivers

aged 25–39 and 40–59 years of age. Thus this may be interpreted as being consistent

with the findings of Harris and Knight-Bohnhoff (1996), that an individual’s

aggressiveness may be susceptible to modification over the course of their life,

increasing age being associated with lower aggression levels. However, this result also

indicates that the increased likelihood of adopting hostile aggressive behaviours on the

road is not exclusive to young drivers.

A significant difference in gender representation was also found between the two

driver types (p < .001). Males were found to be significantly more represented in the

PHA driver group than females, in keeping with earlier aggressive driving research

(Aberg & Rimmo, 1998; Lajunen & Parker, 2001; Lawton et al., 1997; Reason et al.,

1991, VCCAV, 1999). Interestingly, no statistically significant differences were

detected in education levels attained. However, inspection of the frequencies did

suggest that a large percentage (92%) of PHA drivers have attained a considerable level

of education. They have completed their higher school certificate, completed an

apprenticeship or finished TAFE and even university. These results are rather

surprising, considering earlier traffic research, that found a relationship between lower

education and aberrant driving behaviour (Shinar, et al., 2001).

Consistent with earlier research concerning congestion (Hartley & Hassani,

1994; Hennessy & Wiesenthal, 1999; Lajunen, et al., 1999) and study one findings, it

was anticipated that increased exposure to on-road traffic and subsequent congestion

would increase the likelihood of a driver having the potential for hostile aggression on-

road. However, the results indicate there is no significant difference between the two

driver groups (p > .01), contrary to previous research (Hennessy & Wiesenthal, 1999;

Lajunen, et al. 1999). There was no significant difference between the PHA and ‘other

drivers’ in the traffic density they were most often exposed to. Notwithstanding, the

frequencies infer that PHA drivers (53.4%) may drive more frequently in medium

density traffic than any other (see Table L6).


The type of vehicle driven may also contribute to on-road aggression to some

degree, as the results approached significance. Inspection of the frequencies in Table L5

indicates that PHA drivers tend to drive a medium or large car, or a 4WD/Utility/Truck.

These results are consistent with the focus group findings, in which participants reported

vehicle presentation, mechanics, sense of security and size of car as potential causes of

aggressive driving. However, how the type of vehicle driven influences the likelihood

of on-road aggression remains unclear.

5.4.4.2 PHA Driver History of Driving Offences in the Previous Three Years

No significant differences were found between PHA and ‘other drivers’ in the

number of crashes they reported having had in the past three years. Similarly, no

significant differences were found between the two driver groups in the number of

speeding fines and other general driving related fines incurred in the last three years.

However, it is worth noting that within the PHA driver group 34% indicated having

received one or more speeding fines in the past three years. Finally, a larger, significant

proportion of PHA drivers than ‘other drivers’, reported having one or more drink-

driving charges in the last three years.

5.4.4.3 PHA Driver Self-reported Driving Behaviour

A significant difference was found in the preparedness of PHA and other drivers

to engage in speeding behaviour. Significantly more PHA drivers indicated they would

be ‘extremely likely’ to exceed the speed limit by 10km/h or more on an urban road than

other drivers (p < .05). Further, significantly more PHA drivers indicated they would be

‘extremely likely’ to exceed the speed limit by 10km/h or more on a highway than other

drivers (p < .001).

These results are particularly noteworthy, as they suggest that PHA drivers are

more likely than general drivers to travel at excessive speed not only on highways, but

urban roadways. The suggestion that this behaviour may be indicative of PHA drivers is

consistent with the focus group findings where n = 27 young drivers reported speeding

as a contributing factor or behaviour that characterises aggressive driving behaviour.

Consequently, the inclusion of speeding in studies of aggressive driving appears

justified.


A significantly greater proportion of PHA drivers reported it would be ‘more

likely to extremely likely’ that they would drink then drive (p < .05). Further,

proportionately more PHA drivers did not rule out the possibility of driving under the

influence of drugs compared to ‘other drivers’ (p < .05). These findings would suggest

that PHA drivers may be more likely to engage in on-road risk-taking behaviours.

5.4.4.4 Differences in Psychological Characteristics

The PHA driver group were found to have significantly higher overall AQ and

subscale scores, than the ‘other driver’ group (p < .001). Thus, these results indicate that

PHA drivers may have greater levels of physical aggression, verbal aggression, angry

aggression and hostile aggression than the general driving population. Interestingly, as

this measure reflects trait tendencies for aggression, this result also indicates that

perhaps PHA drivers are also more likely to express aggression in contexts other than

the driving environment.

In the context of problem solving, measured using the SPSI-R (D’Zurilla et al.,

2002), PHA drivers were found to have significantly higher rank scores on NPO (p <

.005) and ICS (p < .001) than the ‘other driver’ group, suggesting they adopt more

negative and impulsive problem-solving strategies when faced with on-road situations

that may or may not be interpreted as anger-provoking. However, there was no

significant difference between the drivers groups on RPS, indicating that perhaps PHA

drivers have access to similar levels of rational problem solving to other drivers. Why

PHA drivers do not adopt more rationale problem-solving strategies in the driving

environment remains unclear. Perhaps activation of their high trait aggression levels

influences the social problem-solving style adopted.

Finally, there was a significant difference in the level of negative emotion

reported by drivers prior to undertaking the study. PHA drivers again ranked

significantly higher than the ‘other driver’ group (p < .001), on this measure. If

considered a reflection of the amount of stress being experienced by an individual, this

result suggests that PHA drivers experience, or are experiencing, greater levels of

general life stress than ‘other drivers’. At the same time, this result suggests that they

experience more negative emotion at any given point in time than ‘other drivers’. This

would be consistent with the findings for PHA drivers having higher levels of negative


problem solving, outlined above. As this study did not investigate individual ‘state’

stress in detail, it is recommended that more research be conducted in this area. Effort

should also be given to identifying the sources of such stress.

5.4.4.5 PHA Driver Emotional, Cognitive and Behavioural Responses

Recalling that the two scenarios presented to each participant involved a

potentially anger-provoking scenario (Scenario One) and an ambiguous, potentially less

anger-provoking scenario (Scenario Two), significant differences were found between

the two driver groups and their emotional, cognitive and behavioural responses to each.

As detailed in L7, PHA drivers ranked significantly higher on emotional, cognitive and

behavioural responses in both situations.

Consequently, this suggests that PHA drivers experience stronger negative

emotional and more negative thoughts in response to an on-road incident, even a

relatively ambiguous one as represented by Scenario Two (p < .001). These results may

indicate that PHA drivers will have more difficulty controlling their emotions and as a

consequence greater difficulty controlling their behavioural responses. They are also

more likely to perceive threat than other drivers when faced with on-road ambiguity that

may have the potential to be anger-provoking as in Scenario Two (p < .001), consistent

with human aggression research that found that individuals high on trait aggression will

be more likely to detect threat in their surrounding environment (Dodge & Coie, 1987).

Further, the PHA driver is more likely to respond with instrumental aggressive

behaviour than drivers in general in either situation (p < .001). They are also more

likely to have such an incident influence their later on or off-road behaviour.

In light of the earlier findings concerning problem solving, perhaps this latter

result is due to PHA drivers having less constructive problem-solving strategies, which

in turn results in greater residual affect which these drivers appear to be unable to

regulate effectively. Also, as PHA drivers have been identified as being higher on ICS,

a number of them appear to be responding to these situations in an impulsive, reactive

manner involving little conscious thought. In the context of aggressive driving, these

findings would suggest that conscious decision making and evaluation of outcomes has

little to do with aggressive behaviour on-road, contrary to the GAM (Anderson &


Bushman, 2002). However, it would be wise to explore this concept further in Study

Three.

5.4.4.6 Prediction of PHA Group Membership

Overall, the factors contained in the theoretical framework of aggressive driving

reliably distinguished PHA drivers from ‘other drivers’ (Nagalkerke R2 = .39).

However, prediction of PHA group membership was not overly impressive, with only

29.3% of PHA drivers correctly predicted.

Of the person-related predictors, gender, age and trait aggression scores (as

measured by the AQ) were found to be significant. Females are more likely to be

identified with the ‘other driver’ group and higher trait aggression was predictive of

PHA group membership. The response variables, negative emotion, perceived threat

and likelihood of an instrumental aggressive behavioural response also proved to be

significant individual predictors of PHA group membership. PHA drivers are more

likely to experience more intense negative emotion and perceived threat in response to

an on-road incident and more likely to engage in instrumental aggressive behaviours on

the road. Finally, the results also suggest that PHA drivers are significantly more likely

to drive medium to large vehicles or four wheel drives than small vehicles. In short,

there appear to be a number of psychosocial differences between PHA and ‘other

drivers’.

5.4.5 Implications for the Proposed Theoretical Framework of Aggressive Driving

Overall, the findings of Study Two confirm the applicability of the factors

contained in the proposed theoretical framework of aggressive driving (Figure 4.3). The

sequencing of the relationships illustrated in Figure 4.3 also appears to be robust.

Indeed socio-demographic, driving exposure, trait person-related and state person-

related variables are brought to the on-road environment at any time. Previous Study

One and Two findings suggest that trait person-related factors contribute to a driver’s

initial interpretation of ‘other driver’ behaviour as intentional or benign. Further, the

findings of both the general driving sample and the PHA driver group indicate that when

exposed to an on-road incident, individual drivers experience negative emotions such as

frustration/anger, rage and feelings of threat. These emotions also appear to influence

the likelihood of making negative attributions about the ‘other driver’. Thus, these


findings show support for the ‘present internal state’ proposed within the GAM (Figure

3.1) that we inferred from the ‘emotional and cognitive responses’ depicted in Figure

4.3. Indeed, these elements appear critical to the study of on-road aggression.

A driver’s ‘emotional and cognitive’, encompassing negative emotions and/or

feelings of threat and negative attributions, influence the likelihood of adopting either an

instrumental or hostile behavioural response on-road. Although this study indicates that

the individual characteristics that a driver brings to the on-road environment contributes

more to the adopted behavioural response than other factors in the proposed model.

Finally, Study Two results appear to indicate that the possible ‘post event

influence’ of on-road aggression influencing the likelihood of behaviour in subsequent

encounters on or off-road, is minimal. However, this may have been due to the

artificiality of the scenarios. From another perspective, it fails to account for the

evidence concerning psychological and physical injuries that can be caused by

aggressive driving, especially from the victim’s perspective (DCPC, 2005). As such,

further research on the actual psychological impact that aggressive driving has on

victims is recommended. In the interim, the inclusion of the ‘post event influence’ in the

theoretical model of aggressive driving appears to add minimal exploratory value.

Notably, the factors included in the proposed theoretical framework did not

include all facets of the GAM ‘decision making model’ (Section 3.5.3), specifically an

explicit measure of the adoption of thoughtful or impulsive behavioural responses. As

Study One findings suggested that the decision-making processes associated with

aggressive driving behaviour appear difficult to recall. However, the use of the two

scenarios and measure of behavioural responses may be interpreted to infer some

element of ‘intentional’ or ‘impulsive/risky’ behavioural responses based on the

extremity of the behavioural response likely to be adopted. Conversely, however, the

use of scenarios lacks the situational, real-time, cues that have the potential to influence

the likelihood of intentionally or impulsively adopting behavioural response. Also, it is

noted that in Study One findings participants had difficulty recalling their behaviours as

deliberately decided upon, therefore, this would suggest that this area of the model

requires closer examination. This is not meant to imply that these processes do not


occur or are not important in the study of aggressive driving. On the contrary, this

merely indicates that more research is required in this area.

5.4.6 Overview of Findings and Theoretical Implications

In the exploration of the theoretical framework based on the GAM (Anderson &

Bushman, 2002) this study has shown significant support for the psychological

components included in the proposed framework. The study has also illustrated the

complicated relationships that exist between the various components. In addition, the

results have highlighted the significance of on-road situational factors and their

interaction with various socio-demographic and person-related factors in determining the

likelihood of a driver’s emotional, cognitive and subsequent behavioural response.

Indeed, the study of aggressive driving appears as complex as the study of human

aggression in other social settings.

The results indicate that socio-demographic, trait and state person-related

variables contribute to a driver’s interpretation of an on-road incident as anger-

provoking or not, consistent with Shinar’s (1998) model of aggressive driving as well as

the GAM model of human aggression (Anderson & Bushman, 2002). The use of the

two scenarios, one clearly provocative and the other ambiguous in nature, not only

highlighted driver differences in perception of on-road behaviours, but illustrated

differences in emotional, cognitive and behavioural responses in both cases.

Use of human aggression theory in the GAM (Anderson & Bushman, 2002)

facilitated exploration of three main types of response to perceived provocation:

emotional, cognitive and behavioural. The study found that having perceived on-road

provocation, a driver will experience emotions such as frustration, anger and/or threat.

It is also likely that drivers that experience intense emotion will experience negative

attributions about the ‘other driver’. Subsequent to these responses, a driver may adopt

instrumental or hostile aggressive on-road behaviours. However, whilst the study found

some support for Shinar’s (1998) instrumental/hostile distinction of on-road aggression,

the characteristics of these behaviours require closer examination. In particular, there is

a need to further examine Shinar’s assertion that drivers will react in a hostile (as

opposed to instrumental) manner when the path to their goal is blocked. Indeed, the

results of this study raise the possibility that the decision to adopt a hostile behaviour


may reflect a preparedness by some to abandon their goals, at least in the short-term.

This issue is further discussed in Section 6.4.

In the study of the emotions associated with aggressive driving, the foregoing

analyses demonstrated considerable support for the inclusion of ‘perceived threat’ as a

motivating factor in aggressive driving behaviour. Thus, reference made to the

perception of on-road behaviour as ‘threatening’ in the provisional definition of

aggressive driving (Section 2.2.5.3) appears to be justified. This finding is also more

consistent with the GAM (Andersen & Bushman, 2001) that suggest feelings of threat or

dangerousness can result in aggressive behaviour, and contrary to Shinar’s solely

frustration-aggression based model of aggressive driving.

Importantly, the results also suggest that many of the psychological components

considered in the GAM based framework appear to be dependent on the trait person-

related characteristics of a driver. In the exploratory regression analyses, person-related

factors were repeatedly found to contribute a significant proportion of the variance.

Although, it should be acknowledged that the operationalised variables fell short of

explaining much of the variance and some researchers would suggest that this may be

explained, in part, by the order in which the variables were entered into the regression

equation (Cohen et al., 2003). As such, the results of this study and the review of human

aggression literature would suggest that a closer examination of the person-related

characteristics contributing to aggressive driving is warranted, particularly among

potentially hostile aggressive drivers.

5.4.7 Study Limitations

A primary limitation of the study centres on the possibility of social desirability

bias. As participants normally wish to present themselves in a favourable manner, there

is the possibility they will underreport on measures of aggression (McCloskey &

Coccaro, 2003). However, as detailed in Chapter One, due to the difficulties associated

with direct provocation and observational methods in the context of aggressive driving,

although the self-report is acknowledged as having its limitations, it has been found

useful in aggression research (McCloskey & Coccaro, 2003).

Other limitations centre around the use of, and design of, the scenarios. The

artificiality of presenting participants with on-road written ‘scenarios’ may lack realism,


but arguably most drivers are able to relate to this topical issue and are able to imagine

their behavioural responses. Additionally, as explained in Section 5.2.2.1, the results of

piloting prompted the inclusion of a sense of ‘off-road’ stress in Scenario Two.

However, it is possible that this may have introduced a potentially confounding factor

which may have unintentionally added another layer of complexity to Scenario Two.

Consequently, due regard should be given to this possibility when interpreting the

results.

Notably, future research may be able to measure actual participant responses in

terms of physiological changes such as heart rate and blood pressure, in response to

driving scenarios presented within a driving simulator. Such an approach combined

with qualitative information collected at the time may improve the reality of the use of

scenarios in driving research. Another limitation is that the use of tertiary students as

part of the sampling may have resulted in an overrepresentation of young drivers in the

final sample for Study Two. Further, this may have contributed to the slightly bimodal

distribution of the age groups as reflected in the 2 x 4 ANOVAs (Appendix I) and

regression analyses, the survey having netted greater numbers of 17–24 year olds and

40–59 year olds than the other two age groups. Therefore, due caution should also be

exercised in the interpretation of any age-related results.

Further, it is acknowledged that a number of the statistically significant loadings

for many of the variables in the regression analyses were quite low. It is acknowledged

that the order in which the variables were loaded into the regression equation may have

contributed to the relatively low variance accounted for by subsequent factors.

However, the order in which the variables were entered was driven by the GAM based

aggressive driving model that evolved from Study One and as outlined at Section 5.2.5.

Other limitations of note pertain to the theoretical framework of aggressive

driving proposed for this research (Figure 4.3). Firstly, the person-related and on-road

situational factors considered in this study, are only a small number that are considered

relevant to aggressive driving behaviour. Secondly, neither the theoretical framework,

nor the questionnaire, explored the decision-making process outlined in the original

GAM proposed by Anderson & Bushman (2001). In particular, due to the limitations of

the design, it was not possible to directly operationalise the ‘present internal state’


component of the model. Rather, the emotional and cognitive responses of the

participants were assessed as indicators of this construct. Further, the number of

measures employed needed to be limited in order to contain the length of the

questionnaire, increasing the likelihood of participant co-operation. Lastly, given the

role of driver perception of situational characteristics in on-road aggression (Lennon,

Watson, Arlidge & Fraine, under review), it was not possible to consider all the factors

that have the potential to trigger an aggressive behavioural reaction on the road (Lonero

& Clinton, 1998).

With regard to the examination of the identified PHA driver group, this study

demonstrated that person-related characteristics differentiate PHA drivers from general

road users. Unfortunately, in terms of person-related differences, the study only

examined trait aggression and problem-solving styles. As such, closer examination of

the person-related characteristics of the PHA driver is warranted. Additionally, many of

the strengths and weaknesses outlined above apply to the exploratory analysis involving

the PHA drivers.


This study has demonstrated the relevance of a number of psychosocial variables

to the likelihood of aggressive driving behaviour. The findings also highlighted the

relevance of perception in the likelihood of adopting either an instrumental or hostile

behavioural response. Importantly, consistent with human aggression theory, the study

highlighted a number of key psychological factors that contribute to the likelihood of on-

road aggression, over and above a driver’s trait aggression levels. Hence, for the

remainder of the research program a greater emphasis will be placed upon examining a

wider range of trait and state person-related characteristics of aggressive drivers.

In review, the foregoing results would suggest that the number of hours driven

per week, the traffic density experienced and the type of vehicle driven, do little to

identify the more aggressive driver. Contrary to some of the aggressive driving

literature, a history of crash involvement, speeding and/or other infringements also does

little to identify the more aggressive road user. However, the findings suggest that the

PHA driver is more likely to be 17–24 years of age and male. This driver is also more

likely to have been charged with drink-driving in the last three years. The results also


indicated that the more aggressive drivers may be more prepared to engage in risk-taking

behaviour such as speeding and drink/drug driving. They are also potentially more

likely than general drivers to have higher levels of trait aggression and poorer problem-

solving ability. As such the results suggest that the most significant differences lie at the

deeper, person-related level. Therefore, Study Three will approach the examination of

aggressive driving from the perspective of self-reported hostile aggressive drivers. In

this final study, significantly more attention will be paid to the person-related

characteristics of the hostile aggressive driver.



Chapter Six: Examination of the Psychosocial Characteristics of Self-reported

Hostile Aggressive Drivers

6.1 Introduction........................................................................................................... 253 6.1.1 Relevant Research Questions and Areas to be Explored ........................ 254 6.2 Method ................................................................................................................ 255 6.2.1 Design ..................................................................................................... 255 6.2.2 Procedure ................................................................................................ 257 6.2.3 Participants ............................................................................................. 257 6.2.4 Statistical Analysis ................................................................................. 258 6.2.5 Measures ................................................................................................. 258 6.2.5.1 Stressful Life Experiences Screening ....................................... 258 6.2.5.2 Aggression Questionnaire ........................................................ 259 6.2.5.3 Social Problem Solving Inventory – Revised .......................... 259 6.2.5.4 Carlson Psychological Survey .................................................. 259 6.2.5.5 Barratt Impulsiveness Scale – Version 11 (BIS-11) ................ 261 6.3 Results ................................................................................................................ 263 6.3.1 Socio-Demographics .............................................................................. 263 6.3.2 Driving Characteristics ........................................................................... 263 6.3.3 History of Driving Offences and Charges .............................................. 264 6.3.4 Historical Background ............................................................................ 264 6.3.4.1 Familial Backgrounds .............................................................. 264 6.3.4.2 Victims of Abuse/Neglect ........................................................ 264 6.3.4.3 History of Delinquency and/or Violence ................................. 265 6.3.4.4 Negative Peer Associations ...................................................... 265 6.3.4.5 History of School Conduct Problems ....................................... 266 6.3.4.6 Clinical History ........................................................................ 266 6.3.5 Clinical Background ............................................................................... 266 6.3.5.1 Trait Aggression ....................................................................... 268 6.3.5.2 Social Problem Solving ............................................................ 268 6.3.5.3 Impulsivity ............................................................................... 268 6.3.5.4 Carlson Psychological Survey (CPS) ....................................... 269 6.3.5.4.1 Chemical Abuse (CA) ........................................... 269 6.3.5.4.2 Thought Disturbance (TD) and Validity (VAL) ... 270 6.3.5.4.3 Anti-Social Tendencies (AT) ................................ 271 6.3.5.4.4 Self-Deprecation (SD) ........................................... 272 6.3.5.5 CPS Typing .............................................................................. 272


6.3.6 Qualitative Analysis of Hostile Aggressive Driving Incidents .............. 273 6.3.6.1 Situational On-Road Triggers................................................... 273 6.3.6.1.1 Road Characteristics .............................................. 273 6.3.6.1.2 Passenger Effect .................................................... 273 6.3.6.1.3 Gender of the Other Driver .................................... 273 6.3.6.1.4 Reference to the Other Driver's Vehicle ................ 273 6.3.6.1.5 Behavioural Triggers ............................................. 274 6.3.6.1.6 Range of 'Other Driver' Behaviours ...................... 274 6.3.6.1.7 Perceived Attitude of 'Other Driver' ...................... 275 6.3.6.2 Situational Off-Road Triggers .................................................. 276 6.3.6.3 Emotional Responses................................................................ 276 6.3.6.4 Cognitive Responses ................................................................ 278 6.3.6.5 Physiological Arousal ............................................................... 279 6.3.6.6 Behaviours Engaged by Hostile Aggressive Driver Group ...... 279 6.3.6.7 Consequences of the Hostile Aggressive Driver Behaviour .... 281 6.3.6.8 General Attitudes of the Hostile Aggressive Driver................. 282 6.3.6.9 Lack of Personal Insight ........................................................... 283 6.3.6.10 Other Experiences as the Perpetrator ....................................... 283 6.4 Discussion ............................................................................................................. 283 6.4.1 Case Study Experiences as a Hostile Aggressive Driver ....................... 284 6.4.1.1 On-Road situational factors ...................................................... 284 6.4.1.2 Situational Off-Road Triggers .................................................. 285 6.4.1.3 Emotional Responses................................................................ 286 6.4.1.4 Cognitive Responses ................................................................ 286 6.4.1.5 Physiological Arousal ............................................................... 287 6.4.1.6 Behaviours Adopted by the Hostile Aggressive Driver ........... 288 6.4.1.7 Consequences of the Hostile Aggressive Driver Behaviour .... 288 6.4.1.8 General Attitude of the Hostile Aggressive Driver .................. 289 6.4.1.9 Levels of Personal Insight in the Hostile Aggressive Driver ... 289 6.4.1.10 Other Experiences as the Perpetrator ....................................... 290 6.4.2 Person-Related Characteristics of the Hostile Aggressive Driver Group ...................................................................................................... 290 6.4.3 Exposure to Developmental Risk Factors for Aggression ...................... 292 6.4.4 Trait Person-Related Characteristics ...................................................... 295 6.4.5 General Psychological Characteristics ................................................... 296 6.4.6 Hostile Aggressive Drivers and the Theoretical Framework of Aggressive Driving ................................................................................. 299


6.4.7 Strengths and Limitations of the Research ............................................. 302 6.4.8 Recommendations for Future Research.................................................. 303 6.4.9 Chapter Summary ................................................................................... 304



6.1 Introduction

Study One explored the psychosocial factors contributing to aggressive driving

from the perspective of young drivers due to their over-representation in aggressive

driving statistics (Harding et al., 1998; Lajunen & Parker, 2001; Lawton & Nutter,

2002; VCCAV, 1999). The results of this study also identified a number of ‘on’ and

‘off-road’ factors that may contribute to driver aggression. Additionally, they

identified a number of psychological processes encapsulated within the GAM

(Anderson & Bushman, 2002) that appear to influence the likelihood of aggressive

driving behaviour (refer to Figure 4.3). Study One also indicated that highly

aggressive drivers appear to engage in on-road aggression in two ways:

• Using a vehicle and the on-road environment as a means of expressing off-

road generated aggression; and/or

• Whilst driving, responding to provocative triggers that are encountered in the

on-road environment.

Study Two examined the explanatory value of the psychosocial factors included

in the theoretical framework outlined at Figure 4.3. The results indicated that a

number of person-related factors were significant predictors of both instrumental and

hostile aggressive behavioural responses. These include age, trait aggression, and

negative problem solving and impulsive/careless problem-solving styles. However,

only trait aggression and impulsive/careless problem-solving style were found to be

uniquely predictive of hostile aggression. Additionally, the emotional and cognitive

response variables (negative emotions, perceived threat and negative attributions)

were found to significantly predict self-reported instrumental aggression (Table

5.21), but not hostile aggression in response to Scenario One (Table 5.23).

In a set of exploratory analyses undertaken at the end of Study Two, 88

potentially hostile aggressive drivers (PHA) were identified and their responses

compared to the remaining drivers in the sample (n = 838). The analysis found that

while hostile aggressive drivers are more likely young drivers, 25–59 year old drivers

were no more likely to be categorised as hostile aggressive drivers. In response to

the two scenarios detailed in Study Two, hostile aggressive drivers also ranked

significantly higher on their emotional, cognitive and behavioural response scores

than the remaining drivers (refer to Table K5). As such, they appear to initially

experience greater negative emotionality and cognitions in the face of perceived

provocation. Subsequently, they appear more likely to respond with both


instrumental and hostile reactive aggression to on-road provocation. These drivers

were also more likely to report engaging in speeding behaviour, drink and/or drug

driving. These findings support the existing body of evidence which suggests that

the differences between hostile drivers and ‘other drivers’ lies at the person-related

level. It also suggests that hostile aggressive drivers are more likely to engage in

illegal or socially unacceptable behaviours, consistent with the risk factors for

aggression, as previously outlined in Chapter Three.

Overall, these results suggest that hostile reactive aggressive behaviour on the

road is influenced more by internal, person-related factors and less by situational, on-

road situational factors. There appear to be two main areas of difference at the

person-related level: hostile aggressive drivers appear to have higher levels of trait

aggression as well as impulsive/careless problem-solving style. In terms of on-road

situational factors, however, the hostile aggressive driver also appears more likely to

perceive provocation when faced with ambiguous, as well as provocative on-road

behaviours than other general drivers. Therefore, the differences between highly

aggressive drivers and other drivers appear to exist at a trait, person-related and

cognitive level. Consequently, Study Three was driven by the need to obtain a better

understanding of the psychosocial indicators that characterise hostile aggressive

drivers. Given the general lack of research evidence available regarding this group

in the road safety literature, and the difficulties associated with recruiting a

representative sample of these drivers, it was decided to adopt a case-study approach

to this final component of the research. It is recognised that hostile aggressive

drivers represent only a minority of the drivers on the road. However, from a road

safety and public safety perspective, this is a group warranting further investigation

due to the potentially severe consequences of the behaviour which they may be

prepared to engage in on the road.

6.1.1 Relevant Research Questions and Areas to be Explored

The findings of Studies One and Two suggest that there are several important

issues that need to be explored specific to hostile aggressive drivers, consistent with

the following research questions.


driving behaviour?

If self-reported hostile aggressive drivers do differ from other drivers at the

person-related level, do they adopt/experience the same cognitive and affective


processes as those drivers prepared to engage in instrumental, aggressive driving

behaviours? Although this study will not directly involve a comparison between

hostile aggressive and other drivers, it will enable an in-depth exploration of the

cognitive and affective experience of aggressive driving from the perspective of the

self-reported hostile aggressive driver. This exploration will be framed within the

proposed theoretical framework of aggressive driving developed from the GAM

(Figure 4.3).

RQ6 Are there differences in the characteristics of those drivers who are

prepared to engage in hostile acts of aggressive driving compared to those

who report engaging in only instrumental acts of aggressive driving?

Study Three will explore in greater depth the psychosocial characteristics of self-

reported hostile aggressive drivers. Further to the findings of both Studies One and

Two, and the issues emerging from the Chapter Three literature review, it is

proposed that the self-reported hostile aggressive driver may:

• have a history of violence/aggression in areas of their life other than the

road;

• be more likely to exhibit signs of drink/drug abuse;

• have higher levels of trait aggression than the general population;

• have greater maladaptive problem-solving orientation than the general

population;

• exhibit distorted thinking;

• have had more close encounters with law enforcement officials;

• exhibit anti-social tendencies;

• exhibit difficulties with emotion management; and

• be more likely to engage in impulsive/reactive behaviours.

6.2 Method

6.2.1 Design

The use of a qualitative case-study approach to this study was considered

necessary for several reasons. Primarily, the exploration of trait person-related

characteristics and developmental risk factors for aggression warranted the

personalised attention of a qualified counsellor. Additionally, a case study approach

facilitates the comparison of similarities and differences between participants.

Consequently, a questionnaire was designed to facilitate the exploration of


participant exposure to developmental risk factors for aggression (see Appendix L).

In the first instance, participant socio-demographic data and history of driving

violations were collected. Participants were then assessed on several psychological

measures (refer to Section 6.2.4) in order to facilitate comparison between the

studies: Stressful Life Experiences Screening – Short Form (SLES-S); the Carlson

Psychological Survey (CPS); and the Barrett Impulsiveness Scale – 11 (BIS-11).

Participants were also assessed on several of the measures used in Study Two (refer

to Section 6.2.4). A semi-structured interview was also devised to explore

participant experiences as perpetrators of aggressive driving (see Appendix M).

Several methods of recruitment were considered. Firstly, recruitment of self-

reported highly aggressive drivers via a media release was considered. However,

this was discounted as the target group of interest may have been less likely to come

forward and/or continue to co-operate for the purpose of research. The researcher

had access to the Men’s Information and Support Association (MISA), a community

based counselling organisation, where a predominantly male clientele seek assistance

for a wide range of issues e.g. relationship and anger management difficulties.

Subsequently, a number of participants were recruited through MISA. It is

acknowledged that participants recruited from this source may result in a sample that

is not necessarily representative of all potentially hostile aggressive drivers in the

general driving population. However, the use of this sample allowed the researcher

to access a group who potentially may have experienced anger-management

problems on the road. The criteria for selecting participants for this study were

driven by the three behaviours which helped identify the hostile aggressive driver

group in Study Two (refer to Section 5.2.1). Specifically, the participants needed to

report engaging in one of the following behaviours within the last two years:

• having gotten out of their vehicle to physically or verbally abuse

another driver;

• using their vehicle to intimidate another road user; or

• using their vehicle to damage the vehicle of another road user.

The selection of the two-year period was designed to balance the likelihood

of identifying such drivers with the need to include sufficient recency to avoid

potential recall problems.


6.2.2 Procedure

MISA participants were recruited via in-house advertising (Appendix N). If

interested in participating, MISA clients left their name and contact number with

reception for contact by the researcher. Similar advertising was also placed across

three Queensland University of Technology (QUT) campuses and the Northpoint

College of TAFE campus in order to attract interested staff or students. The

advertisement was also placed on the QUT internet noticeboard. In all cases,

interested parties were invited to contact the researcher by phone or email. Upon

contact, participants were screened by the interviewer to ensure that they met the

selection criteria.

Prior to commencing the interview participants were asked to read and sign a

consent package (Appendix O). The administration of this study was broken into

two stages: a survey stage and an interview stage. Firstly, participants were asked

socio-demographic questions as well as questions relating to their driving history.

They were then administered the SLE, AQ, SPSI-R subscales, CPS and BIS-11

respectively. At the end of the survey stage, they were asked if they had ever been

officially charged with any driving offences or other general offences. The full

survey was read to participants to account for the possibility of literacy difficulties.

Full administration of the survey and interview took approximately 1.5 hours.

During the interview stage of the process, participants were asked to recall

the aggressive driving incident that met the above selection criteria. At relevant

points throughout the interview participants were asked key questions consistent with

the factors identified in the theoretical framework at Figure 4.3, similar to the

questions that were explored in Study One (refer to Appendix M). This was

considered necessary in order to examine whether self-confessed hostile aggressive

drivers experience similar psychological processes as less aggressive drivers when

involved in an on-road incident. At the completion of the interview, participants

were reimbursed $60.00 for their time and travelling expenses. All interviews were

conducted within the confines of the MISA counselling premises, to ensure the safety

of the researcher.

6.2.3 Participants

From a total of 22 potential participants recruited through QUT and MISA,

10 participants met the selection criteria outlined in Section 6.2.1. Only one of the


participants was female. Participant ages ranged from 24 to 55 years (M = 41.6

years). Nine participants were recruited through MISA and one from QUT.

6.2.4 Statistical Analysis

Although this study primarily adopted a qualitative case study approach, it

was possible to test for statistical differences between the self-reported hostile

aggressive drivers and other relevant groups on all of the standardised measures

detailed above. Given the inherent difficulties in comparing different samples

recruited via different recruitment strategies, these tests were undertaken for

exploratory rather than confirmatory purposes. Despite the low sample size, when

comparing the 10 case studies to the other driver groups identified in other research

or Study Two (i.e. n = 88 or n = 926), a series of independent sample t-tests were

considered appropriate for these analyses (Sheskin, 2004). Additionally, the use of

independent t-tests provides a more accurate estimate of the underlying sampling

distribution for the data when the sample size is small and the sample variance is

problematic (i.e. less than 25) (Sheskin, 2004, p. 423). As several t-tests were

conducted, the tests were subject to appropriate Bonferroni adjustment (refer to

Tables 6.1 and 6.2).

Additionally, in order to determine any statistically significant difference

between the individual case study scores on the AQ, SPSI-R, CPS and BIS-11 and

the pre-published means of relevant comparison groups, participant scores were first

converted into ‘z’ scores using the SD and M of the comparison group to determine if

there were any statistical differences: Z = (X - µ) / σ (Sheskin, 2004).

6.2.5 Measures

6.2.5.1 Stressful Life Experiences Screening

The Stressful Life Experiences Screening – Short Form (SLES-S) screens for

major life events that may be considered stressful and significant in a person’s life

(Stamm et al., 1996). In this study, the SLES was used as a measure of the amount

of violence and stressful life events that participants have been exposed to

throughout their developmental years. The SLES-S consists of 20 items. In response

to each example of stressful life experiences, participants are required to indicate

their response on a ‘0’ to ‘10’ Likert type scale from ‘I did not experience’ to

‘exactly like my experiences’.


In Study One, six drivers referred to prior exposure to violence or aggression

in their lives. Use of the SLES-S in Study Three had the potential to provide a richer

understanding of high-level aggressive driver backgrounds. The data gathered via

this survey was used as personal, contextual information for each case study.

6.2.5.2 Aggression Questionnaire

All four subscales of the AQ were administered to participants: the physical

and verbal aggression subscales, the general anger scale and the hostility subscale

(Buss & Perry, 1992). Thus the measure of trait aggression consists of 29 items.

Participants rated how characteristic the items were of themselves on a 5 point Likert

Scale (1 = extremely characteristic of me, 5 = extremely uncharacteristic of me).

The internal reliability of the full 29 items was relatively high in Study Two, with a

Cronbach’s α of .90 (Appendix I).

6.2.5.3 Social Problem Solving Inventory – Revised

As in Study Two, only three subscales of the SPSI-R (D’Zurilla, Nezu, &

Maydeu-Olivares, 2002) were used in Study Three. The internal reliability of each

of the subscales was evaluated for Study Two and the corresponding Cronbach’s

alpha were: negative problem-solving orientation (.84); impulsive/carelessness style

(.77); and rational problem solving (.82) (Appendix I).

6.2.5.4 Carlson Psychological Survey

The Carlson Psychological Survey (CPS) is primarily designed for use with

individuals who have been accused or convicted of crimes, or otherwise referred to

the authorities for socially deviant behaviour. Considering this target group of

interest, this test has been designed to make few literacy demands of the individual

without sacrificing reliability (Carlson, 1982) (see Appendix N). High-level

aggressive driving behaviour may also be considered socially deviant behaviour and

at times may result in criminal behaviour, e.g. assault or property damage. As such,

administration of this survey was deemed particularly relevant to the exploration of

person-related characteristics of high-level aggressive drivers. The factors explored

by these measures included developmental, behavioural and cognitive factors that

have been statistically found to be associated with the increased likelihood to

respond aggressively and antisocially to perceived provocation.


As detailed in Section 3.2, such factors have been found to be associated with the

adoption of aggressive/antisocial behaviours.

The CPS requires participants to respond to 50 questions. Responses are

indicated on a graded scale (1 to 5) to allow participants to indicate the degree of

applicability of the item. Participants are also given space to comment on each of the

items should they wish to make any comments about each question. Scoring

involves totalling the items relevant to each subscale.

The items comprise four subscales: chemical abuse (CA); thought disturbance

(TD); antisocial tendencies (AT); and self-depreciation (SD). A ‘validity’ scale (V)

was also added to provide an indication of the participant’s ability/willingness to

maintain an appropriate test-taking attitude.

The CA scale reflects the degree to which a person abuses drugs/alcohol and

the relevance of this abuse to their antisocial behaviour. The TD scale reflects

disorganised thinking, confusion and perceptual distortions and feelings of unreality.

These traits manifest themselves in unusual affect and/or anxiety. High scores on

this scale indicate that the individual has problems dealing with reality as they have

difficulty organising themselves in their work or private lives. They may be

emotionally upset, moody and miserable (Carlson, 1982).

The AT scale is a measure of hostility and socially defiant attitude. It also

reflects the person’s willingness to be assaultive or threatening. This may or may not

manifest in the form of physical aggression, however, it is indicated by willingness to

engage in malicious conversation and a “mocking, unfriendly manner” (Carlson,

1982, p. 1). Receiving a high score on this scale indicates that the individual is likely

to be cynical of other people, interpreting their behaviour as unjust or self-serving.

They are also likely to be accepting of criminal behaviour, preferring the values of

those who commit crimes. They may act in unethical and untrustworthy ways,

feeling little or no guilt associated with this behaviour (Carlson, 1982).

The SD subscale indicates the degree to which the individual degrades or

belittles themself and their actions. Scores on this scale may be either a trait

disposition or a mood state. High scores on the SD indicate that the individual does

not value themself or their accomplishments, suggesting the existence of

despondency, depression and perhaps suicidal tendencies.

As part of the development of the measure, two groups of n = 216 male

offenders were tested to develop the validity of the instrument. In addition, the


validity of the measure was later verified with a group of 311 female offenders,

among other populations (Carlson, 1982). The measures of reliability associated

with these tests for males and females are reported at Table R1.

Participant scores on the five scales are plotted onto a profile sheet. The

graphic representation of their results indicates one of 18 profiles or offender types

that have been identified in the development of this measure. The range of scores on

each subscale and the type of offender they represent are outlined at Appendix S.

However, it should be noted that the CPS does not provide a brief descriptor of

offender types. Rather, it provides for numerical typing, i.e. Type 1 etc. As such, a

short descriptor of each offender type has been formulated in consultation with

another researcher who has extensive experience with the measure (refer to

Appendix S).

6.2.5.5 Barratt Impulsiveness Scale – Version 11 (BIS-11)

Chapter Three outlined a brief review of the developmental risk factors for

aggression. In a review of impulsivity, high levels of impulsivity were found to be a

key indicator for a number of diagnosable disorders, such as ADHD, ADD, ODD

and ASD. Such diagnoses are characterised with aggressive tendencies and greater

risk-taking behaviour (e.g. ADHD, ADD, CD, ODD and ASD) (Section 3.2.2.4)

(Bor, 2004; Fossati, Barratt, Carretta, Leonardi, Grazioli, & Maffei, 2004; Iacano,

Carlson, Taylor, Elkins, & McGee, 1999; Volavka & Citrome, 1998). High scores

on BIS impulsivity have been found to be significantly correlated with the self-

reported number of impulsive aggressive episodes in the previous month (Stanford et

al., 1995). Further, high impulsivity was found to be significantly but negatively

correlated with social problem solving (D’Zurilla, Nezu, & Maydeu-Olivares, 2002;

McMurran, Blair, & Egan, 2002). As Study Two results indicated a potential

relationship between problem-solving style and the likelihood of aggressive driving

behaviours, this study adopted the use of the BIS-11 to further explore the

relationship between the SPSIR’s problem-solving style and the trait measure of

impulsivity as measured by the BIS-11.

The available evidence suggests that there are three main components of the

first order personality trait, impulsivity: motor impulsiveness; attentional

impulsiveness; and non-planning (Miller Joseph, & Tudway, 2004; Patton, Stanford,

& Barratt, 1995). In 1995, these researchers administered the 30 item, BIS-11 to


four different samples: undergraduates, substance abusers, general psychiatric

patients and prison inmates (refer to Table R2). The internal consistency co-

efficients for the BIS for these groups ranged from .79 to .82 (Patton et al., 1995).

Table R3 is a list of the means, standard deviations and alpha co-efficients associated

with the BIS-11 subscales as per a general population of n = 245 (Miller et al., 2004).

Participant scores will be compared to both of the means and standard deviations

contained in both Tables R2 and R3.

Each of the 30 items in the BIS-11 demand a 1-4 Likert type scale response:

‘1’ - ‘rarely/never’ through to ‘4’- ‘almost always’. Total BIS scores are the sum of

the full 30 items, whilst the subscales are the sum of the items relevant to each scale.

6.2.5.6 Collection of Socio-Demographic and Driving Behaviour Data and the Semi-

Structured Interview

In order to provide a contextual backdrop for the clinical and qualitative data

to be gathered, the following socio-demographic data was collected prior to the

administration of the above measures: gender, age, marital status, income, driving

experience (in years) and education attained were recorded (refer to Appendix N).

As an appropriate background question to some of the clinical data collected it was

also necessary to ask participants if they had any prior experience with mental health

professionals, and for what reason.

As participants were identified as self-reported hostile aggressive drivers, it

was also considered necessary to ask questions about their daily driving behaviour,

such as type of vehicle driven, hours driven per week and the density of traffic they

most often experience (Appendix N). Additionally, participants were asked

questions about their crash involvement and traffic offences in the previous three

years. They were also asked to report the likelihood of driving under the influence of

alcohol or drugs (Appendix N).

The second stage of the data collection process was qualitative and involved

the participant recalling their experience as a hostile aggressive driver. The protocols

exploring the hostile aggressive driver’s experience with aggressive driving were

based on the GAM (Anderson & Bushman, 2002) and also guided by the protocols

designed for Study One, where young driver experiences with aggressive driving

were explored. The exploratory questions were also guided by Study Two findings

that highlighted several psychological constructs/processes as potentially relevant to


aggressive driving behaviour, specifically, emotions, cognitions, physiological

responses (see Appendix O).

6.3 Results

Individual participant scores on the AQ, SPSI-R, BIS-11 and CPS with their

statistical significance to pre-established means are outlined at Appendices U and V.

The relevance of these scores to each individual is discussed in the Case Study

Profiles outlined at Appendix W. The overall sample results are discussed under the

relevant headings below.

6.3.1 Socio-Demographics

Seven of the case study participants were either married (n = 2) or living in a

defacto relationship (n = 5). Three were either divorced (n = 1) or recently separated

(n = 2).

Participant incomes varied considerably. Four participants were low income

earners (n = 1) or in receipt of government benefits (n = 3). Another four earned

reasonable incomes i.e. $31,000 to $50,000 per year. Two participants earned in

excess of $70,000 per year.

None of the participants had attained a university level education. However,

seven of them had completed high school certificates (Year 10, n = 5; and Year 12, n

= 2). Two participants had either completed an apprenticeship or a TAFE certificate.

One participant left school after primary school (i.e. Year 7).

6.3.2 Driving Characteristics

Though three of the participants reported driving large vehicles or 4WDs, the

majority of participants reported driving medium (n = 5) or small vehicles (n = 2).

As road users, the sample most frequently drive on city/town roads (n = 6). Seven of

the case studies have been driving for more than 20 years. The remaining three have

been driving for various periods of time: 3–5 years (n = 1); 6–10 years (n = 1); and

11–15 years (n = 1).

Four participants reported driving most frequently on highways or open

roads. Only one participant (a professional truck driver) reported driving more than

20 hours per week. Two other participants reported driving 16–20 hours per week,

due primarily to work commitments. However, most of the participants reported

driving 6–15 hours per week: 6–10 hours (n = 2), and 11–15 hours (n = 5).


When asked to indicate the likelihood of driving under the influence of

alcohol or drugs, the majority of participants indicated that it would be ‘not at all

likely’ they would drink-drive (n = 6) or drive under the influence of drugs (n = 8).

6.3.3 History of Driving Offences and Charges

Within the last three years, four of the case study participants had been

involved in one to three road crashes. The remainder had not had any crash

involvement. None of the drivers reported having committed drink-driving offences

in the last three years. However, five of the drivers reported having received one or

two ‘speeding’ fines in the past three years. Further, three of the participants

admitted to fines for ‘unlicensed driving’ in the same time period.

Outside of this three-year period, all ten participants had a history of driving

violations. In light of the fact that many of the participants have been driving for

over 20 years, this may not be that surprising. However, some of the individual

histories of violations were extensive and, therefore, noteworthy (refer to Individual

Case Studies at Appendix U). Between them they had amassed: in excess of 25

speeding fines, 10 drink driving charges (n = 5 participants), four charges of

unlicensed driving, five counts of red light running or dangerous driving (n = 5), one

count of ‘hooning’, and three other road offences (n = 1).

6.3.4 Historical Background

6.3.4.1 Familial Backgrounds

One of the case study participants reportedly came from a supportive family

(CS1). Another reportedly came from a similar background, however, the

participant’s responses to other questions suggested that there may have potentially

been a history of psychological disorders (e.g. hypochondria) (CS9). Only two of the

participants came from single-parent families. Seven of the eight remaining

participants reported that they regularly witnessed domestic violence between their

parents. Six participants also reported a history of alcohol abuse by their mother

and/or father. Nine of the participants reported no family history of drug use. One

participant reported that his mother was a ‘Bex addict’ as well as an alcoholic (CS5).

6.3.4.2 Victims of Abuse/Neglect

Eight participants reported growing up within problematic families. All eight

of these were subjected to various forms of abuse as children or young adults:


physical abuse by a parent, (n = 7), and sexual abuse by a family friend or stranger (n

= 2). Two participants spoke of being raped as adults: one was raped whilst serving

time in prison, and one was reportedly raped whilst extremely drunk.

6.3.4.3 History of Delinquency and/or Violence

Three participants reported no history of ‘other’, off-road offences or charges.

However, the remaining seven participants had attracted numerous other charges,

illustrating relatively high levels of anti-social behaviour. Some participants claimed

that these ‘other charges’ were incurred primarily whilst they were ‘younger’. The

most recent charges involved ‘wilful damage’ and ‘actual bodily harm’ (n = 3),

specifically related to the hostile aggressive driving incident cited by the participants

(CS2, CS8 and CS9). The ‘other’ charges self-reported by the seven participants are

summarised below:

• six counts of ‘assault’ or ‘actual bodily harm’ (n=6) (CS1, CS2, CS5, CS8,

CS9, CS10);

• one current Domestic Violence Order (n = 1) (CS7);

• two counts of ‘attempted murder’ (n = 1) (CS4);

• two counts of ‘arson’ (n = 1) (CS4);

• two counts of ‘criminal damage’ or ‘wilful damage’ (n = 3) (CS2, CS8, CS9);

• two counts of ‘breaking and entering’ (n = 2) (CS2, CS5); and

• four counts of ‘stealing’ (goods and motor vehicles) (n = 4) (CS5, CS8, CS9).

It should also be noted that during the course of the interviews, four participants

reported having been involved in a number of ‘bar fights’ that were never reported to

the authorities.

6.3.4.4 Negative Peer Associations

Four participants were reportedly involved in organised ‘gang’ culture during

their adolescence (e.g. skinheads) (CS2, CS3, CS4 and CS5). Though not all

participants were directly involved in organised gangs, a total of nine participants

reported association with less than positive peer groups during their adolescence.

The nine stated that their friends came to the attention of local authorities ‘some of

the time’ (n = 6), or ‘often’ (n = 3).


6.3.4.5 History of School Conduct Problems

All but one participant reported having caused ‘a little’ (n = 1) or

‘considerable’ (n = 8) trouble at school. Four participants reported regular truancy.

6.3.4.6 Clinical History

At various points in their lives, all ten participants have accessed

psychological/psychiatric or general counselling services. However, this is not that

surprising considering most of the participants were recruited through MISA. Only

three participants had not sought counselling for potentially clinically diagnosable

disorders. Five participants had sought counselling for depression, one of whom had

also been recently diagnosed with ADHD. One participant has been diagnosed with

Bipolar Disorder and another has been diagnosed with Dissociative Identity

Disorder.

In support of the proposal at Section 6.1.1 that hostile aggressive drivers will

exhibit difficulties with emotion management, six out of 10 case study subjects

expressed difficulty regulating their ‘anger’. However, in light of the selection

criterion to participate in this study, it would appear that all 10 participants may

experience this problem. Importantly, five of these individuals were not seeking

counselling for anger difficulties, but for other issues.

6.3.5 Clinical Background

A series of independent sample t-tests were conducted to test for differences

between the 10 self-reported hostile aggressive drivers and the participants in Study

Two (refer to Section 6.2.4 for rationale). Firstly, the participants in the case study

were compared to the overall Study Two sample (n = 926) to explore whether they

differed from the general driving population (See Table 6.1).

Secondly, the Study Three case study participants were compared to the hostile

aggressive driver group identified in Study Two (n = 88) (See Table 6.2). The results

of both sets of independent sample t-tests are discussed under the respective

headings.


Table 6.1 Independent sample t-tests of self-reported hostile aggressive drivers on

AQ and SPSI-R subscales compared to overall study two sample (n = 926)

Variable

Case Studies

(n=10)

Study Two Sample (n=926)

Significance Level

M M Total AQ Scores

90.40***

46.98

t(df9) = 5.785, p < .001

AQ Subscales Physical Aggression

26.00***

10.48

t(df9) = 7.618, p < .001

Verbal Aggression

19.10* 11.21 t(df9) = 4.238, p < .01

Angry Aggression

20.40*** 9.50 t(df9) = 6.147, p < .001

Hostile Aggression

24.90* 15.77 t(df9) = 3.377, p < .01

SPSI-R Subscales Negative Problem Orientation

5.88**

5.21

t(df9) = 3.405, p < .017


5.66 5.16 t(df9) = 2.094, p > .017


3.30 3.32 t(df9) = -.123, p > .017

* p<.01, ** p< .017 and ***p<.001

Table 6.2 Independent sample t-tests of self-reported hostile aggressive drivers on

AQ and SPSI-R subscales compared to the PHA drivers identified in study two (n =

88)

Variable

Case Studies (n=10)

PHA Drivers (n=88)

Significance Level

M M Total AQ Scores

9.40*

62.32

t(df9) = 3.606, p < .01

AQ Subscales Physical Aggression

26.00***

16.42

t(df9) = 4.522, p < .001

Verbal Aggression

19.10 13.63 t(df9) = 2.844, p > .01

Angry Aggression

20.40* 12.66 t(df9) = 4.237, p < .01

Hostile Aggression

24.9 19.61 t(df9) = 1.874, p > .01

SPSI-R Subscales Negative Problem Orientation

5.88

5.33

t(df9) = 2.714, p > .017


5.66 5.38 t(df9) = 1.106, p > .017


3.30 3.16 t(df9) = .573, p > .017

*p<.01, **p< .017 and ***p<.001


6.3.5.1 Trait Aggression

When the sample mean of the 10 case studies was compared to the overall

Study Two sample (n = 926), the case studies were found to have a significantly

higher mean on the AQ and all four subscales at p < .01 or better (Table 6.1).

Overall, these results suggest that the self-reported hostile aggressive drivers in this

study have trait aggression levels higher than the Study Two participants in general.

As detailed in Table 6.2, the mean of the 10 case studies on the AQ and two of

the subscales was found to be significantly higher than that for the Study Two

‘hostile aggressive’ driver group (n = 88). The results of the test for the total AQ

score and the significant subscales were: total AQ, t(df9) = 3.606, p < .01, physical

aggression, t(df9) = 4.522, p < .001, and angry aggression, t(df9) = 4.237, p < .01. In

each case the sample mean was significantly greater than the mean of the comparison

group. However, there was no significant difference between the case study mean

and the potentially hostile aggressive drivers identified in Study Two on the ‘hostile

aggression’ and ‘verbal aggression’ subscales, t(df9) = 1.874, p > .01 and t(df9) =

2.844, p < .01 respectively.

6.3.5.2 Social Problem Solving

When the case study means were compared with the means of the overall

Study Two sample (n = 926), again, a significant difference was found in negative

problem orientation (NPO), t(df9) = 3.405, p < .017, but no other subscales.

Interestingly, there were no significant differences in levels of ICS and RPS between

the case studies and either of the comparison groups.

The mean of the case study group was compared with the hostile aggressive

driver group (n = 88) on the three SPSI-R subscales (Table 6.1). The case study

group means were not found to be significantly higher than the ‘potentially hostile

aggressive’ driver group on any of the SPSI-R subscales, suggesting there were no

differences between these two groups in social problem-solving abilities.

6.3.5.3 Impulsivity

As Study Two results did not include a measure of ‘impulsivity’, individual

case study scores on the BIS-11 were compared to previously published means

(Muller, Joseph, & Tudway, 2004; Patton, Stanford & Barratt, 1995). The results of

these analyses, using Z scores, are presented at Appendix V.


Both male and female participants scores on the BIS-11 subscales were

compared to the published means of a ‘general population’ (n = 245, 108 male and

137 female) (Muller, Joseph, & Tudway, 2004). Tests of the individual scores

revealed no significant difference between participant scores and the ‘general

population’ on motor impulsivity. Two participants (CS1 and CS7) scored

significantly higher on non-planning impulsivity (z = 2.16, p < .05; z = 2.16, p < .05

respectively). Further, three participants (CS1, CS4 and CS6), scored significantly

higher on cognitive impulsivity than the ‘general population’ (z = 1.96, p < .05; z =

2.26, p < .05; and z = 1.96, p < .05 respectively).

There were no significant differences on the total BIS-11 scores, between the

male case study participants and the mean published for an inmate population (Patton

& Barrat, 1995). No significant difference was found between the female

participant’s total score on the BIS-11 and the mean published for a female general

psychiatric group (Patton & Barratt, 1995). The general psychiatric group mean was

chosen as a mean for female inmates was not available. Further, the female

participant reported that she had been previously diagnosed with a psychological

disorder (i.e. Bipolar Disorder). Therefore, this seemed an appropriate comparison

for exploratory purposes.

6.3.5.4 Carlson Psychological Survey (CPS)

Individual participant scores were compared to the published means (see

Table R1) (Carlson, 1982). The results for each participant are presented at

Appendix V. Note that these means relate to an incarcerated population, whilst

referring to their ‘normal’ drug and alcohol intake prior to prison (Carlson, 1982).

6.3.5.4.1 Chemical Abuse (CA). Comparison of individual scores on the

chemical abuse (CA) subscale revealed only one significant difference. Case Study

Two (male) recorded significantly higher on the scale than the prison population (z =

1.98, p < .05). Closer examination of the individual responses to questions relating

to the past and future consumption of alcohol and/or drugs revealed more detailed

results.

Two participants reported that they drank alcohol ‘all of the time’ and four

participants indicated that they drank alcohol ‘more than once a week’. Whilst two

participants reported that they would drink ‘about once a week’, three of the


participants indicated that they would drink ‘once in a while’ (n = 1) or ‘never’ (n =

2).

When asked if they had ever used drugs, only two participants reported

having no experience with them. The remaining participants had experimented with

them or were still using the substance of choice (i.e. primarily marijuana): ‘once or

twice’ (n = 3); ‘most of the time’ (n = 4); and ‘all the time’ (n = 1).

With reference to their future use of alcohol or drugs, only two participants

responded that they would ‘never’ use either again. The remaining participants

responded accordingly: ‘once in a while’ (n = 2), ‘once a week’ (n = 1), ‘two or

three times per week’ (n = 4), and ‘more than three times per week’ (n = 1).

6.3.5.4.2 Thought Disturbance (TD) and Validity (VAL). Comparison of

the scores on the thought disturbance subscale revealed one significant difference

(see Appendix V). Case Study Four recorded a significantly higher score on levels

of thought disturbance when compared to the prison population (z = 2.06, p < .05).

This participant also scored significantly higher on the validity subscale (VAL) than

the incarcerated group (z = 2.63, p < .05).

Examination of the individual responses to TD items provided some

contextual emphasis for these results. Given five possible responses to CPS –

Question 5, five subjects reported feeling ‘a little down but OK’. Three responded

that they felt ‘sad some of the time’, whilst two reported feeling ‘sad a lot of the

time’. In addition to these responses, the case study participants showed a degree of

changeability in their emotional state. Specifically, in response to CPS – Question

27, three participants indicated that they ‘change from happy one minute to sad the

next’, ‘once in a while’. Five of the participants responded that they change from

happy to sad, ‘some of the time’. The remaining two participants responded that

they experience such change in emotions ‘most of the time’ (n = 1) and ‘all of the

time’ (n = 1).

In addition, as an insight to the possibility of more substantial thought

disturbance patterns the case study responses to CPS – Question 8 were examined.

In response to this question, only one participant reported that he had ‘never’ ‘seen or

heard things that were not there’. Three participants responded that they had

experienced this phenomenon once or twice. However, five of the participants

responded that they had ‘seen or heard things that were not there’ ‘more than once or


twice’. The remaining participant (CS2) reported having had this experience ‘often’,

however, this is consistent with his diagnosis of Dissociative Identity Disorder.

6.3.5.4.3. Anti-Social Tendencies (AT). Again, only one participant (CS2)

scored higher on anti-social tendencies (AT) than the reference group (z = 1.99, p <

.05) (refer to Appendix T). There were no other significant differences between

participant scores on anti-social tendencies and the mean scores for the incarcerated

group. Again, the study examined individual participant responses to the items

concerning anti-social tendencies, to gain contextual insight into these results.

In response to CPS – Question 9, nine of the ten case studies advised that

they had ‘told others off’, ‘often’ (n = 3) or ‘many times’ (n = 6). Interestingly, four

of the participants said that they enjoyed fighting ‘a little’ (n = 1) or ‘some’ (n = 3).

Six of them indicated they did not enjoy fighting ‘at all’. When presented with ‘if

someone hit me, I would….’ (CPS – Question 37), only one person was unsure of

what they would do. The remaining participants responded: ‘hit him once’ (n = 3),

‘hit him several times’ (n = 4), and ‘beat him up’ (n = 2). Such results warrant

concern as participants indicated the number of times they have carried a weapon

(CPS – Question 50): ‘never’ (n = 2), ‘once or twice’ (n = 5), ‘some of the time’ (n =

1), ‘most of the time’ (n = 1), and ‘all of the time’ (n = 1).

When asked if they would be in ‘trouble again’ (CPS – Question 45), only

one participant suggested that he would ‘never’ again be in trouble. Three

participants answered that they ‘do not want to be’ in trouble again. Although,

whilst six of the participants did not want to be in trouble again, they ‘probably

would be’ (n = 5) or will be ‘once or twice more’ (n = 1).

However, when asked to reflect about the ‘illegal things’ that they have done

(CPS – Question 31), two individuals reported that they feel ‘very sorry’ and three

felt ‘sorry’. However, five participants reportedly were ‘not sorry, or never think

about’ the illegal things they have done.

Participant responses to CPS – Question 34, were informative. The item

posed: ‘if someone tried to cheat me, I would…’ Seven participants responded that

they would ‘forgive but not forget’ when faced with such a situation. The remaining

case studies (n = 3) reported that they would ‘make him/her sorry’. These results

suggest that as a whole this group are less likely to ‘forget’ wrongdoings and are

perhaps more likely to hold onto a grudge.


As detailed in the case studies at Appendix W, six participants indicated that

they had caused trouble ‘more than 7 times’ whilst at school (CPS – Question 13).

Only one participant reported ‘never’ causing trouble at school.

6.3.5.4.4. Self-Deprecation (SD). There were no significant differences

between the individual scores on SD when compared to the mean of the incarcerated

group (Appendix T). Examination of the participant scores on certain items, again,

provided a contextual backdrop to assist with the interpretation of the results.

When presented with CPS – item 21, ‘most people seem to think I am…’

participants were to respond with how good or bad people thought they were. Five

of the participants responded that they were perceived as ‘a bit better than others’ (n

= 2) or ‘a very good person’ (n = 3). Two indicated that they were ‘just like

everyone else’, whilst three reported they were perceived as ‘a bit worse than others’.

Despite these reported perceptions, when presented with CPS – item 32, ‘people

seem to like it better when I…’ nine participants indicated that others liked it better

when they: ‘talk a little’ (n = 3), ‘I am there but do not bother them’ (n = 2), ‘I just

listen’ (n = 3), and ‘I am not there’ (n = 1). Only one participant reported that

‘people would like it better’, if he talked ‘a lot’. Interestingly, this participant was

profiled as Type 13 – ‘self-centred’.

Participants were asked to indicate, in general, how ‘good’ or ‘bad’ their lives

have been (CPS – item 49). Six participants responded that they have had an

‘average’ (n = 2) to ‘bad’ life: ‘as bad as most people’ (n = 3), and ‘worse than most

peoples’ (n = 1). Four cases reported that they had lives ‘as good as most peoples’ (n

= 2), or ‘better than most peoples’ (n = 2). The responses to this item also provide

insight into the positive or negative thinking of the participants. In particular, the

former results would suggest more negative thinking.

6.3.5.5 CPS Typing

Consistent with the traditional use of the CPS on groups that deviate from the

socially acceptable norms, the scores of the ten case studies were plotted into one of

18 ‘Types’ (Carlson, 1982) (Appendices T & W). Seven of the participants were

classified Type 5 - ‘markedly antisocial’. Two of the case studies were classified

Type 16 – ‘negative/explosive’, whilst the remaining participant was classified as

Type 13 – ‘self-centered’ (Appendices T & W).


Examination of the detailed profiles at Appendix W suggest that the hostile

aggressive drivers in this sample have a psychological profile not dissimilar from

that of an ‘inmate population’ on measures of chemical abuse, anti-social tendencies,

thought disturbance and self-depreciation (Carlson, 1982). All participant scores

were either not statistically different from the mean for this population, or were

found to have significantly higher scores on the various subscales (refer to

Appendices V and W).

6.3.6 Qualitative Analysis of Hostile Aggressive Driving Incidents

The following analyses focus on the circumstances and processes involved in

the hostile aggressive driving incidents discussed with the participants. In all of the

cases investigated the participants reported being the instigators of the hostile

aggressive behaviour.

6.3.6.1. Situational On-Road Triggers

6.3.6.1.1 Road Characteristics. Eight of the incidents reported by

participants were initiated on a main, city/town road. Two of the incidents occurred

on a highway/freeway. The level of traffic congestion experienced at the time of the

incident was either ‘medium’

(n = 5) or ‘heavy’ (n = 5).

6.3.6.1.2 Passenger Effect. Only two participants were travelling with

passengers at the time of the incident. However, in both cases the passenger either

directly or indirectly influenced the behaviour of the driver, as detailed in the case

studies (CS8 and CS10, Appendix U). These incidents will be addressed in more

detail below under ‘Situational Off-Road Triggers’ (Section 6.3.6.2).

6.3.6.1.3 Gender of the Other Driver. Although not necessarily the trigger

or cause of the incident, it was observed that in the majority of incidents the ‘other

driver’, or victim, was male (n = 8). In only two instances, the victims were female.

6.3.6.1.4 Reference to the Other Driver’s Vehicle. When recounting their

stories as aggressive drivers, three participants made reference to the vehicle of the

‘other driver’ (refer to comments at Table 6.3). In all three cases, the comments

appeared to reflect a negative perception of the ‘other driver’.


Table 6.3 References made about the vehicles of the ‘other drivers’

Case Study

Comment

CS5

“He had a nice, black car, tinted windows and the rest.”

CS6 “I was driving a s…box and he was driving a nice Toyota ute.”

CS8 “I thought, what an a…hole. I’m in my shiny new car, you’ll give way, I’m coming out (CS8 assuming the thoughts of the ‘other driver’).”

6.3.6.1.5 Behavioural Triggers. Across the ten case studies, three

behaviours were cited as the primary trigger for the resultant aggressive driving

incidents: being cut-off (n = 5), tailgating (n = 3), and being subjected to slow

driving (n = 2). It is important to note that driver perception of these behaviours as

deliberate or personally meaningful appear to contribute to the increased likelihood

of an aggressive response to these behaviours. Table 6.4 is an example illustrating

each of the behaviours, linked to the relevant case studies.

Table 6.4 Examples of primary behavioural trigger for aggressive driving incidents

Case Study

Behaviour Comment

CS2

Cutting Off

“….I was driving along all mellow and I got cut off.”

CS6 Tailgating “..merging onto the highway….got onto the highway and an old mate in a ute come flying up my a…e. He sat right on my pickle for a kilometre.”

CS4 Slow Driving “This guy was doing 50 in a 70k zone and there were no other restrictions.”

6.3.6.1.6 Range of ‘Other Driver’ Behaviours. Immediately following the

primary trigger behaviours, participants cited a range of subsequent behaviours that

were adopted by the ‘other driver’. Table 6.5 outlines the range of other behaviours

adopted and their frequency. As can be seen, more than one ‘other behaviour’ was

adopted by seven participants, suggesting that in many cases the ‘other driver’

contributed to the escalation of the on-road incident. CS1 did not report any


additional behaviour for the ‘other driver’ aside from the primary trigger, ‘slow

driving’.

Table 6.5 Subsequent behaviours adopted by the ‘other driver’

Other Behaviours Frequency Case Study

Gesticulating

4

CS2, CS4, CS8, CS9

Verbal Abuse

5

CS5, CS6, CS7, CS8, CS9

Stopping

3

CS5, CS6, CS7

Red Light Running

1

CS3

Tailgating

1

CS10

6.3.6.1.7 Perceived Attitude of ‘Other Driver’. During the course of the

interviews, seven participants made comments about the ‘other driver’ and their

apparent attitudes and related behaviour. Participants made reference to feeling

‘intimidated’ (n = 5) by the other driver, whilst others made reference to their

behaviour as ‘inconsiderate’ (n = 2), ‘stupid’ (n = 1) or ‘angry’ (n = 1). Examples

are outlined at Table 6.6.

Table 6.6 References to the perceived attitudes of the other drivers

Case Study

Perceived Attitude

Comment

CS5

Intimidating

“…he wanted me to get out of his way, he was trying to intimidate me.”

CS8

Inconsiderate

“This bloke was just inconsiderate!”

CS7

Angry

“His attitude. It was a real angry attitude.”

CS9

Stupid

“…that he (...the other driver) had done something stupid anyway.”


6.3.6.2 Situational Off-Road Triggers

Prior to the aggressive driving incident two case study participants reported

that they had been drinking (CS4 and CS6). When participants were asked how they

were feeling immediately before the act of aggressive driving, six participants

reported a range of stressful off-road factors: tired as a result of working all day (n =

1), recent separation from spouse (n = 1), argument with partner (n = 1), death of a

parent (n = 1), a child having run away from a foster home (n = 1), and having to

move house (n = 1). As illustrated in Table 7.7 below, these precursor events appear

to have increased the amount of state stress the individual was experiencing

immediately prior to the event.

Table 6.7 Pre-event off-road stressors cited by participants

Case Study

Comment

CS1

“I was tired….I had done a full day’s work….I just wanted to go home.”

CS3

“Stressed. I had just separated from my wife after 20 odd years and there was a lot going on.”

CS4

“I was really p….off because (my partner) and I had had a verbal that afternoon and I jumped in the car and took off.”

CS5

“My dad had recently passed away from a sudden heart attack…suppose I was still pretty upset about it. I remember being pretty cut up.”

CS8

“I was upset because we had just got a phone call from my partner’s daughter (in foster care) saying that she had just run away and she wanted us to…pick her up. I was upset and I had my partner in the car who was being a bit hysterical at the time.”

CS9

“I suppose having to move and the hassle of moving.”

6.3.6.3 Emotional Responses

Nine of the case studies cited experiencing a considerable amount of anger in

response to the ‘other driver’s’ behaviour. A small proportion of these also used the

word ‘rage’, or used words that could reasonably describe ‘rage’ to explain their

feelings. One participant used the word ‘excited’ when talking about the feelings he

experienced during the aggressive driving incident. The female subject (CS10), also


expressed a small amount of ‘fear’ associated with her experience. Table 6.8

illustrates the four main emotions experienced across the case studies at the time of

the aggressive driving incident.

Table 6.8 Examples of range of emotions experienced by participants

Emotion Experienced

N

Comment

Anger

9

“I was angry. I was pissed off.”(CS6) “ ..pissed off….I was pissed off with him.” (CS8)

Rage

5

“…my ‘G’ rate was boiling. I was foaming.” (CS1) “ Pissed off. I was furious.” (CS4)

Fear

1

“I was scared a bit.” (CS10)

Excitement

1

“Actually, I was feeling pretty excited…really stoked up…I lived for that sort of thing.” (CS5)

Interestingly, when the subjects were asked to explore the emotions

associated with the aggressive driving incident, and some of the other major

incidents in their lives, it was observed that five of them had considerable difficulty

articulating them (CS2, CS4, CS7, CS9 and CS10). Some of these difficulties may

be due to dissociative tendencies, others appeared to lack the ‘words’ to express

themselves. For example, despite the use of probing questions, one subject was

unable to recall any emotions associated with the aggressive driving incident (CS2).

His inability to express his emotions also extended to the discussion surrounding

earlier traumatic events in his life. When this observation was shared with him, he

responded:

“Yeh, because I have learned to block a lot out during my life, I can even

block out pain. I can block out a lot of things. That’s like when my girlfriend

stabbed me in the back with a fork, I just said ‘what are you doing?’…The

first wife held a knife to my throat. I just thought, ‘I want to use that, hurry

up’.” (CS2)


6.3.6.4 Cognitive Responses

Exploration of the negative cognitions associated with the aggressive driving

incident revealed two main themes. Most participants had negative thoughts about

the ‘other driver’ (n = 7) and many had thoughts of taking negative or aggressive

action in response to the situation (n = 8). The latter theme is one that was

previously identified in the focus group discussions of Study One. In that study,

most participants merely had negative thoughts about the ‘other driver’ and their

abilities as a driver. However, ten young drivers reported having thoughts of the

action they would take. In this study, thoughts of taking negative or aggressive

action appear to be a common process for the hostile aggressive drivers under

investigation. Again, some participants had difficulty recalling the thoughts

associated with the incident (CS4, CS7, CS9, CS10). Table 6.9 provides examples of

the cognitive themes.

Table 6.9: Examples of the negative cognitions associated with hostile aggressive

drivers

Negative Cognitions

N

Comment

‘Other Driver’

7

“you stupid prick you shouldn’t be sitting that close up my arse.” (CS5) “..smart arse…” (CS6) “ I thought what an arsehole…” (CS8) “He was such an idiot.” (CS9)

‘Actions to be taken’

8

“I felt like running her off the road. You know, get out of my way or I will put you out of the way. I was really geed up.” (CS1) “…hit him before he hits me.” (CS2) “…I thought, I want to hurt you real bad.” (CS7) “…I’m gonna get you!” (CS10)


6.3.6.5 Physiological Arousal

The subjects reported experiencing a range of physiological reactions to the

aggressive driving incidents. Table 6.10 identifies the range of physiological

changes identified by the subjects. These physiological changes are consistent with

increased levels of adrenaline (Carlson & Buskit, 1997). Two of the participants

were unable to recall or identify any physiological characteristics (CS2 and CS9).

6.3.6.6 Behaviours Engaged by Hostile Aggressive Driver Group

A number of combined behaviours were adopted by the hostile aggressive

driver group in response to the perceived provocation. Table 6.11 provides a detailed

breakdown of the behavioural responses adopted by this group.

Without exception, all of the case study participants verbally abused the other

driver. Additionally, although two of the subjects initially used their horn to express

their anger, all ten incidents escalated to the adoption of highly aggressive

behaviours: following the ‘other driver’ (n = 3), stopping and alighting from the

vehicle (n = 8), using their vehicle to ‘nudge’ the ‘other driver’s’ vehicle (n = 2),

braking to cause a collision with a following vehicle (n = 1), damaging the ‘other

driver’s’ vehicle (n = 6), and physical assault (n = 4).

Table 6.10 Range of physiological changes identified by the case studies

Physiological Changes

n

Example Comments

Hyped 6 “my rate was up, my heart was pumping.” (CS1) “my adrenaline was pumping.” (CS5) “I was pumped!” (CS6) “I felt a rush of blood to my head which put me on a bit of a high.” (CS8)

Tight 4 “Tense, very tense in the chest.” (CS3) “...I felt tight in the chest.” (CS7)

Butterflies and Nausea

1 “I was feeling sick. I had a bad case of butterflies. …felt like I was going to be sick.” (CS4)

Narrowing of Vision

2

“Tunnel vision… it was him and I.” (CS7) “…my eyes, I reckon they become real sharp.” (CS10)


Table 6.11 Range of behaviours adopted by the hostile aggressive driver group

Behaviour n Case Study Examples Horn honking

2

Verbal Abuse

10

“I was fairly vocal behind the wheel..get out of my f…n way, you blind b…ch.:” (CS1) “I went round to his window and said a few choice words, told him he was an f…g idiot.” (CS8)

Stopping and Alighting from vehicle (n=4 alighted from vehicle at a set of lights)

8

“I grabbed my club lock from under the seat and I got out.” (CS5) “We stopped at the next set of lights, so I got out of my car and walked up to his window to give it to him.” (CS3)

Following the ‘other driver’

3

“He eventually went around me and turned off, so I followed him.” (CS5) “He went around the corner and I followed him. I followed him home actually. It was just around the corner.” (CS9) “She stopped ‘following’ us…so I did a U-turn and went back.” (CS10)

Nudging a vehicle from behind

2

“I actually tapped her in the boot.” (CS1) “I put my foot down and nudged him a few times.” (CS4)

Braking to cause a collision

1

“I chucked on the anchors and sent him far up my arse. He hit me at 90km per hour.” (CS6)

Damaging another vehicle

6

“His whole front end was just smashed.” (CS6) “Started laying into his car with the club lock…the bonnet, the windscreen, his driver door and side mirror.” (CS5) “ I started wriggling his side mirror side to side.” (CS8) “I grabbed my big Maglite and smashed the mirror on the side of her car.” (CS10)

Physical Assault

4

“…he cut me off. It was just a normal reaction. I’ve been taught not to back down from anything. He’s got out of the car, so I just belted him…I broke my knuckle.” (CS2) “I said ‘mate, it’s on’..and so I just hit him and it was on…for a few minutes, until they pulled us apart. I got a broken jaw out of it….and three police cars turned up.” (CS7) “When he went to open his door to get out, I slammed the door back on his hand.” (CS8) “He clipped me behind the ear…I hit him and he went down and hit his head on the concrete. Over the fence he just went through, and into the concrete…..(found out later) ambulance came and took him to hospital.” (CS9)


6.3.6.7 Consequences of the Hostile Aggressive Driver Behaviour

Despite the potential for all of the above behaviours to attract the

involvement of police, only four of the aggressive incidents cited did so (see Table

6.12). Of these, only two of the participants were charged.

After the incident, nine of the drivers reported that they gave the matter little

or no further thought (Table 6.12). Following a particularly violent incident (CS5,

Table 6.12), one driver reported that he had a ‘celebratory drink’. Only two drivers

commented that they continued to ruminate over the event. One driver reported that

he continued to be ‘a bit worried’, due to his previous criminal history and the

possibility of police involvement.

Table 6.12 Examples of real or perceived consequences

Consequences N Comment

Police Involvement None

6

“He wound the window up and took off through a red light…(end of the incident)” (CS3) “Nothing. Nothing at all.” (CS4)

Partial

2

“I went straight to the police station and reported it all for insurance. I wrapped him up pretty good!” (CS6) “You know, three police cars turned up. (When asked if either of them wanted to press charges)…I said no, it’s not worth it. Lot of it was self-defence.” (CS7)

Charges Laid

2

“…he must have got me rego…reported it to the police. I have been charged with wilful damage of this bloke’s car, estimated at $1,000.” (Case pending) (CS8). “…as I drove away they got me number. I was stupid enough to ring the police, when I heard they were looking for me…got 150 hours community service, ‘no time’.” (CS9)

Post-Event Influence None

8

“…never gave it another thought. Went home and was happy to be home”. (CS1) “…not at all, I went down the pub and had a celebratory drink!” (CS5)

Other 2 “I got to a friend’s place and I parked my car in his garage, because I was worried that he would see it...in case the next day he was on patrol or something and spotted my car.” (Incident involved an off-duty policeman) (CS4) “…That wrecked my whole day. I couldn’t get it out of my mind.” (CS10)


6.3.6.8 General Attitudes of the Hostile Aggressive Driver

Within the transcripts, several more general attitudes of the hostile aggressive

driver emerged: lack of remorse (n = 8), sense of justification (n = 10), lack of regret

(n = 8), intentionality (n = 10), and deliberate intimidation (n = 3) (refer to Table

6.13). In addition to the substantial evidence of ‘lack of remorse’ among this group,

all of the participants felt ‘justified’, or offered justification for taking the action that

they did. Only two participants spoke of ‘regret’. However, it should be noted that

one of these expressed regret for having been ‘caught’ (CS9), and the other at having

caused damage to his own vehicle (CS6). When asked questions about the

‘intentional nature’ of their behavioural response, all ten participants expressed

deliberate intent. Further, three of the case study participants spoke of deliberately

trying to ‘intimidate’ the ‘other driver’ in order to influence their behaviour.

Table 6.13 General attitudes of the hostile aggressive driver group

General Attitudes

N

Example Comments

Lack of Remorse

8

“I felt good! I got in before him.” (CS2) “…because I saw it was a young bloke, I didn’t give a shit.” (CS4) “Nuh, no remorse…I think it’s quite hilarious myself.” (CS8)

Sense of Justification

10

“I just wanted to teach him a lesson!” (CS6) “He was being a bully and a smart arse…he actually deserved it.” (CS8)

Intentionality

10

“Guaranteed, it was intentional!” (CS1) “Bloody oath … (I intended to do it).” (C5) “Oh yeh! Intended to hit him.” (CS7)

Deliberate Intimidation

3

“…I was doing it to intimidate.” (CS1) “I just wanted to give him the shits, or scare him, so he would get out of the f…g road.” (CS4) “…I was a bit bigger than him – intimidating.” (CS6)


6.3.6.9 Lack of Personal Insight

As mentioned earlier under ‘Emotional Responses’, some of the participants

had difficulty identifying the emotions they experienced during the incident. It was

also noted that a number (n = 7) of the participants had limited levels of personal

insight. As such they were unable to, or had difficulty, accepting responsibility for

their behaviour when asked ‘Do you think your behaviour could be considered

aggressive?’ Consequently, much of the evidence for this observation is in the lack

of a response, or avoidance of a response to this question. Table 6.14 presents quotes

that overtly illustrated the difficulty.

Table 6.14: Comments illustrating difficulty with personal insight

Case Study Comment

CS4

“Yeh…I guess. Still…”

CS9

“Yeh. But, I could have been a smartarse and put a hanky over it the minute I pulled up.”

CS10

“Yeh. But that’s just my reaction.”

6.3.6.10 Other Experiences as the Perpetrator

Seven of the participants admitted that they had been involved in other

aggressive driving incidents. Four of the participants admitted to being involved in

at least one other incident. Three subjects admitted to involvement in multiple

others. No specific details were sought about these experiences. The remaining

three participants reported having no other experiences with aggressive driving.

However, one of them was extremely evasive and did not directly respond to the

question (CS8). Another, responded that he had not been involved in any other

incidents in the role of the ‘perpetrator’ (CS9):

“No, not on the giving end. No. I’ve been on the receiving end for nothing.”

6.4 Discussion

Before discussing the results of this study, it is necessary to reiterate that the

small sample used was not randomly selected from the general population of

potentially aggressive drivers. Notwithstanding, the study allowed the researcher to


investigate whether individuals with potential anger issues are more prone to

transferring these difficulties to the on-road environment.

Under the relevant research questions, individual results are reported below

where appropriate. The discussion of the person-related results will not only focus

on the socio-demographic characteristics of the case studies, but on the various risk

factors for the development of aggressive tendencies. The latter will be discussed

from a historical, as well as a clinical, perspective.

6.4.1 Case Study Experiences as a Hostile Aggressive Driver


driving behaviour?

6.4.1.1 On-road situational factors

The results concerning the on-road situational factors surrounding the hostile

aggressive incidents discussed with participants are similar to those identified in the

literature review and Study One i.e. type of road, levels of congestion, passenger

effect and gender of the other driver (Elliott, 1999; Hennessy & Wiesenthal, 1997;

O’Brien, Watson,, & Tay, 2004; RACWA, 1997; VCCAV, 1999).

The type of road on which the incidents most commonly occurred was a

main, city/town road in either medium or heavy levels of congestion. Further, two

participants appear to have been influenced by ‘passenger effect’. CS8 was directly

affected by his passenger’s overt distress about an off-road incident. CS10 cited that

she had been travelling with friends, one male and one female. Potentially, their

presence influenced her behaviour indirectly, as the presence of passengers has been

found to influence driving behaviour (Doherty, Andrey, & MacGregor, 1998; Rolls,

Ingham, Hall, & McDonald, 1991; Williams, 2003).

The gender of the ‘other driver’ was male in eight of the 10 incidents cited by

participants. In most instances, the ‘perpetrator’ was male. The female perpetrator

in the study perpetrated her aggression against a female. These results are consistent

with previous findings that suggest that males are not only more likely to be the

perpetrator, but the victim of on-road aggression (O’Brien, Watson, & Tay, 2004;

VCCAV, 1999). However, they may also be a product of the characteristics of the

hostile aggressive driver sample i.e. 9 males and 1 female, n = 10.

The specific on-road behaviours that initially triggered the participants’

hostile aggressive response mirrored those identified in Study One and in the


literature review. Specifically, cutting-off, tailgating and slow driving instigated

negative feelings within the hostile aggressive driver group. It is important to note

that these behaviours may not necessarily be perceived as aggressive by all drivers.

Pivotal to them causing negative emotions, is the perception of the driver. These

behaviours were initially perceived as intentional and personally meaningful by the

hostile aggressive participants. On the other hand, the general population may be

more prepared to perceive them as driving errors, or simply poor judgement on the

part of the ‘other driver’. In addition it is noted that the ‘other driver’ also adopted a

range of other behaviours during the course of the incident: gesticulating, verbal

abuse, stopping their vehicle, red light running and tailgating which appear to have

contributed to the escalation of the incident in some instances (AAMI, 2001; Mizell,

1997; NHTSA, 2002; VCCAV, 1999).

In summary, though qualitative, the foregoing findings provide support for

previous aggressive driving research and Study One findings. The ability for some

on-road behaviours to be perceived as provocative or aggressive by a ‘perpetrator’,

supports the proposition that hostile aggressive drivers have trait or state person-

related differences that differentiate them from the general driving population.

6.4.1.2 Situational Off-Road Triggers

The qualitative, case study findings support the suggestion by other

researchers that off-road factors contribute to state stress levels and subsequent on-

road driving aggression (Arnett, Offer, & Fine, 1997; Navaco, Stokols, & Milanesi,

1990). Six of the case studies indicated that they were under varying degrees of state

stress at the time of the incident, ranging from ‘having worked hard all day’ to recent

separation from a spouse and a family bereavement. In all cases, the precursor

triggers appear to have influenced the amount of state stress experienced. Although,

it should be noted that in most cases the link between this stress and the aggressive

driving behaviour that participants adopted was not made explicit. Research

suggests, however, that the experience of state stress increases the likelihood of

perceiving an incident as provocative (Anderson & Bushman, 2002; Crick & Dodge,

1996; Yagil, 2001). It has also been associated with the activation of feelings of

anger and/or fear, increasing the likelihood of aggressive behavioural responses

(Anderson, 1995). This link is proposed to be made through the activation of


aggressive schemas/scripts that increase the likelihood of an aggressive response to

provocation (Anderson, 1995).

6.4.1.3 Emotional Responses

In response to the perceived provocation, anger was most frequently cited as

the primary emotion. However, these drivers spoke of having considerably high

levels of anger in response to the perceived provocation. A small proportion

nominated the word ‘rage’ to describe their feelings. These results are not surprising,

as they are consistent with the Study Two results and the literature review that

maintains higher levels of anger are associated with more aggressive acts

(Deffenbacher, Deffenbacher, Lynch, & Richards, 2003; Deffenbacher, Huff, Lynch,

Oetting, & Salvatore, 2000; Lajunen & Parker, 2001; Lynch, Deffenbacher, Filetti, &

Dahlen, 1999). Consistent with excitation transfer theory, one participant (CS5)

cited ‘excitement’ as the main emotion experienced in relation to his hostile

aggressive behaviour on the road (Geen, 1990; Zillmann, 1972). He did not cite

‘anger’ as an emotion experienced. Another participant, the only female,

experienced a degree of ‘fear’ in response to the perceived provocative behaviour.

This finding is consistent with Study One findings concerning female drivers and

their experiences with aggressive driving.

Interestingly, it was noted that five of the hostile aggressive drivers had

difficulty articulating the feelings they experienced during the event. In two cases, a

tendency towards dissociation was suspected. In the main, however, most

participants appeared to lack the ‘words’ to express themselves, suggesting the

potential for emotional difficulties or dysfunction. If participants are unable to

express themselves, or connect with their emotions, perhaps this reflects an inability

to know and regulate their own emotions. Research suggests that difficulty, or an

inability to regulate one’s emotions is associated with defensiveness and a tendency

to ruminate, that may lead to impulsive and/or inappropriate behavioural reactions to

the slightest provocation (Caprara et al., 1987; Chang et al., 2003).

6.4.1.4 Cognitive Responses

Consistent with the findings of Studies One and Two and the literature

review, the subjects recalled numerous negative cognitions they had about the ‘other

driver’ (Yagil, 2001). In this study, however, the results suggest that hostile

aggressive drivers have two types of negative cognitions about the incident: those


about the attributes or abilities of the ‘other driver’; and those about what aggressive

action they would like to take. A total of eight of the case studies had negative

thoughts about what action they would like to take in response to the situation. For

example: “I felt like running her off the road…” (CS1)

If negative thoughts about the attributes or abilities of the other driver have

the potential to influence driving behaviour, perhaps having thoughts of taking

aggressive actions further increases the likelihood of aggressive driving behaviour.

After all, conscious and/or subconscious thought precedes action. Hence, perhaps

thoughts about positive or negative actions to be taken may be more apparent among

hostile aggressive drivers.

During the course of the interview, nine of the hostile aggressive drivers also

made reference to the perceived attitude of the ‘other driver’. Five of the case

studies reportedly felt the ‘other driver’ was trying to ‘intimidate’ them. Four of

them reported that the ‘other driver’ was inconsiderate, generally ‘angry’ or behaved

‘stupidly’. This suggests that hostile aggressive drivers may perceive more negative

attitudes emanating from the ‘other driver’.

Finally, whilst discussing the incidents, three of the hostile aggressive drivers

made reference to the ‘other driver’s’ vehicle. In all three cases the participants’

comments reflected their negative perception of the ‘other driver’. As can be seen in

Table 6.9, the participant comments appear to be underpinned by ‘jealousy’. This

finding was particularly interesting, as there has been little work done on aggressive

driving and attitudes other than ‘vengeance’ (Hennessy & Wiesenthal, 2001, 2002).

Perhaps, hostile aggressive driving behaviours are at times also motivated by feelings

of ‘jealousy’ and ‘resentment’.

6.4.1.5 Physiological Arousal

It is widely accepted that the activation of emotions and cognitions associated

with an anger-provoking incident initiates a physiological response (Berkowitz,

1993; Huesmann, 1988; Zillman, 1988). In response to the emotions experienced,

the participants became aware of a range of physiological changes within their

bodies. The majority described feeling ‘hyped’ or ‘pumped’. Four participants

experienced ‘tightness’ in the chest area. Two of the subjects described changes in

their vision, whilst one participant reported feeling nauseous. These physiological

changes are consistent with increased adrenaline levels.


6.4.1.6 Behaviours Adopted by the Hostile Aggressive Driver

All of the participants adopted instrumental, on-road aggression, namely

horn-honking and verbal abuse. However, all of the participants also resorted to

extreme forms of on-road aggression that could easily have resulted in criminal

charges. These behaviours included: stopping their vehicle and alighting from their

vehicle to pursue the matter with the ‘other driver’ at a verbal and sometimes

physical level, resulting in injury or property damage; deviating from their original

journey to follow the ‘other driver’; using their vehicle to nudge or push the vehicle

of a slower driver; and intentionally braking hard in order to cause a collision with a

close-following vehicle.

Results from this sample suggest that hostile aggressive drivers may

intentionally engage in both instrumental and hostile aggressive behaviours on the

road. Consistent with the Study Two findings concerning those behaviours that

should be considered hostile aggressive in nature, most of the observed hostile

behaviours again involved a deviation from the original goal of their journey in order

to ‘deal’ with or send a message to the ‘other driver’. This illustrates the extent to

which hostile aggressive drivers may be prepared to go in order to rectify a perceived

wrong. However, it should be bourne in mind that engaging in hostile aggressive

driving behaviour was the selection criteria for inclusion in the study. Hence, it is

unclear whether instrumental behaviours tend to precede hostile aggressive

behaviours in general, or this was simply a characteristic of the drivers included in

this study.

6.4.1.7 Consequences of the Hostile Aggressive Driver Behaviour

Following the incident, only one subject expressed some concern over the

possible consequences of his actions, due to his previous criminal history (CS4). The

majority of the case studies reported that they gave the incident little or no thought

soon afterwards, suggesting little remorse or regret over their involvement in the

incident. Further, CS5 reportedly went to his local ‘pub’ and had a celebratory drink.

In human aggression research, low levels of remorse have been found to be

associated with anti-social tendencies (Carlson, 1982). Immediately following the

on-road incident, two participants continued to worry or ruminate over the incident

(CS4 and CS10). Such rumination has been associated with ‘emotional


susceptibility’ which reflects a general inability to regulate emotions, increasing the

likelihood of aggressive responses (Caprara et al., 1987).

Interestingly, six of these highly aggressive on-road incidents were not

brought to the attention of authorities. In two instances, authorities were only

partially involved: to report the incident for insurance purposes; and to break up a

public ‘fight’ on a main road (no charges were laid). Only two subjects were

formally charged as a result of an aggressive driving incident. One was waiting a

court date at the time they were interviewed; the other was found guilty of ‘assault’.

These results raise the possibility that aggressive driving incidents may be

underreported.

6.4.1.8 General Attitude of the Hostile Aggressive Driver

Without exception the participants indicated that they felt ‘justified’ in having

taken the action that they did. Some indicated that the ‘other driver’ needed to be

‘taught a lesson’, while others justified their actions by commenting that the ‘other

driver’ ‘deserved it’. Perhaps, therefore, hostile aggressive drivers have more

‘vengeful’ attitudes, in keeping with earlier traffic research that suggests that highly

vengeful drivers are more likely to perceive provocation as aggressive and adopt

more highly aggressive behavioural responses (Hennessy & Wiesenthal, 2001).

Consistent with this thinking, all ten participants admitted that their behavioural

response was intentionally directed at the ‘other driver’.

Additionally, three hostile aggressive drivers admitted to deliberately

attempting to ‘intimidate’, in order to influence the driving behaviour of the ‘other

driver’. This finding is supported by the general attitudes identified as causes of

aggressive driving behaviour in Study One (p. 48).

The overall findings also appear consistent with social interaction theory that

is incorporated in the GAM decision making model (Anderson & Bushman, 2002).

The theory maintains that perpetrator thoughts of justice and the process of laying

blame are highly relevant to aggressive outcomes (Tedeschi & Felson, 1994).

Indeed, thoughts of obtaining justice appear highly relevant to the hostile aggressive

drivers in the sample.

6.4.1.9 Levels of Personal Insight in the Hostile Aggressive Driver

As previously stated, a number of the participants were observed to have

difficulty with identifying the emotions they experienced during the course of the


aggressive driving incident. Similarly, when asked questions concerning their

exposure to stressful life experiences throughout the course of their lives, it was

observed that seven out of 10 experienced some difficulty expressing the emotions

associated with these events. Further, when examining their personal experience as a

perpetrator of aggressive driving, these seven drivers avoided/failed to accept

responsibility for their behaviours. Also noted was a reluctance to accept their

behaviour as aggressive or inappropriate.

6.4.1.10 Other Experiences as the Perpetrator

Although no specific details were collected, many of the case studies openly

admitted to having been involved in several other incidents during the course of their

lives. Though this result was anticipated, it must be considered that seven of the

drivers have been driving for more than 20 years. They have had increased exposure

to the opportunity for aggressive behavioural responses on the roads. Alternatively,

this result may mirror the findings of Study Two where a wider age range was

identified as belonging to the hostile aggressive driver group than had been

suggested by previous research which suggested higher rates of aggressive driving

behaviour in 17–24 year old drivers (VCCAV, 1999; Yagil, 2001). Indeed, if hostile

aggressive driving behaviour is primarily due to person-related factors developed

over the course of one’s life, then aggressive driving behaviour would not necessarily

be isolated to young drivers (i.e. 17–24 years of age). Notwithstanding, these results

may also simply reflect the under-reporting mentioned earlier.

6.4.2 Person-Related Characteristics of the Hostile Aggressive Driver Group



who report only engaging in instrumental acts of aggressive driving?

In light of the strict selection criteria used to assess participant eligibility for

this study the age and gender of the hostile aggressive drivers recruited resulted in

some interesting observations. Notably, the age of the hostile aggressive drivers

ranged from 24 to 55 years of age (M = 41.6 years). This finding may be interpreted

as consistent with the finding of Study Two examining the age and gender

differences in the larger sample (n = 926). As detailed in Section 5.3.6.5, there was

no significant difference in the likelihood of a hostile aggressive behavioural

response between drivers 17–24 years of age and those aged 40–59 years. Further,


the age of the participants is in keeping with the results of the comparison of the

hostile aggressive driver group (n = 88) in Study Two with the ‘other’ drivers (n =

838) from the larger sample (Table 5.2). In Study Two, the drivers in the groups

aged 25–39 years of age and 40–59 years of age were not significantly likely to be

categorised as belonging to either the potentially hostile aggressive driver group or

the ‘other driver’ (i.e. non hostile aggressive) group. Therefore, it would appear that

young drivers are not necessarily the only at-risk group for hostile aggressive driving

behaviour.

Despite the small sample size in this current study, the subsequent

recruitment of nine males and one female may be interpreted as consistent with the

previous studies in this research program and the foregoing literature review: male

drivers appear to be more likely to participate in hostile aggressive behaviours on the

roads (Aberg & Rimmo, 1998; Gordhamer et al., 1996; Lajunen & Parker, 2001).

However, a relevant confound in this finding is that the community health centre

from which the majority of participants were recruited is most frequently accessed by

males (i.e. MISA). Consideration of the other socio-demographic factors also found

some interesting findings concerning hostile aggressive drivers.

Contrary to human aggression research which has long associated lower

levels of education with greater levels of human aggression (Harris & Knight-

Bohnhoff, 1996; Murray, 1998; Shinar, Schechtman, & Compton, 2001) this study

found that a larger proportion of the self-reported hostile aggressive drivers had

attained a certificate level of education i.e. Year 10 or better (Shinar et al., 2001).

This was consistent with Study Two findings where higher education levels were

found to be significantly predictive of the likelihood of adopting instrumental

aggression (p. 196). The majority of subjects were married or living in a de-facto

relationship. Further, six of the drivers earned a reasonable to high level income,

ranging from $31,000 to income exceeding $70,000 per year.

A large proportion of the case studies reported driving for over 20 years. As

road users, the case studies reportedly drive most frequently on city/town roads, and

to a lesser degree, highways, in medium density traffic, consistent with Study Two

findings. Also consistent with Study Two findings, the hostile aggressive drivers

were more frequently identified as driving medium to large vehicles. The majority

also spend 6–15 hours driving per week.


In the self-reported driving characteristics, half of the case study subjects had

attracted speeding fines in the past three years. Further, three participants admitted

to being fined for ‘unlicensed driving’. Although participants reported few other on-

road transgressions in the past three years, when asked about driving-related charges

outside of this period the results indicated extensive histories of violations (see

Appendix W). As detailed in the results, in addition to amassing considerable

speeding fines outside of this three-year period, the participants reported 10 drink-

driving charges, a number of ‘unlicensed driving’ charges, red-light running,

dangerous driving, ‘hooning’, and several other on-road offences.

These results support the proposal that hostile aggressive drivers may be

more likely to ‘exhibit signs of drink/drug abuse’, demonstrated by the relatively

large number of drink- driving charges amassed by these drivers. It also appears that

hostile aggressive drivers may be more likely to have a history of ‘other’ driving-

related offences consistent with the proposal that hostile aggressive drivers may be

more likely to have had more frequent ‘encounters with law enforcement officials’

(Appendix W). Upon review, the violations detailed may also be indicative of a

tendency towards ‘anti-social behaviours’.

6.4.3 Exposure to Developmental Risk Factors for Aggression

The results suggest that hostile aggressive drivers may also be more likely to

originate from dysfunctional family backgrounds. There was very little evidence of

drug abuse in the family of origin. However, the results indicate that the highly

aggressive driver’s family of origin is perhaps more likely to have a history of

alcohol abuse and domestic violence between the parents. These findings are

consistent with existing literature which has found that exposure to domestic

violence increases the likelihood of aggressive and anti-social tendencies (Bor,

McGee, & Fagan, 2004). By itself, exposure to parental alcohol abuse may not

directly cause the development of aggressive tendencies. Rather, the aggressive or

anti-social tendencies are developed via the dysfunctional parenting associated with

the alcohol abuse or via domestic violence that may result from alcohol abuse (Bor et

al., 2004; Dahlberg, 1998; Fagan & Najman, 2003). Children raised in such

backgrounds are more susceptible to the development of delinquent behaviour and

aggressive tendencies, due to poor parent/child communications (Fagan & Najman,

2003). Twin studies have also shown that adolescents with a history of parental


alcohol abuse are more likely to develop negative emotionality, aggression and

negative reactions in response to stressors (Elkins, McGue, Malone, & Iacono,

2004).

Results from this sample also indicated that hostile aggressive drivers may be

more likely to have been subjected to child abuse or neglect than the general driving

population. Seven of the participants reported being subjected to physical abuse by

either their father or mother. Two participants reported sexual abuse within the

family of origin or by a family friend. Exposure to such negative experiences and

less than ideal role models is believed to have increased the risk of these participants

engaging in delinquent or aggressive behaviours in the off-road environment

(Klassen & O’Connor, 1994). As such, it would also seem feasible that this may

have the potential to apply to the on-road environment.

Six of these participants also reported having difficult relationships with the

non-abusive parent (CS2, CS3, CS4, CS5, CS6 and CS10). As a consequence, these

participants also experienced neglect in the form of low levels of love, care or

interest and were therefore at risk of participating in delinquent behaviours during

adolescence (Kensella, 1996).

A number of participants were involved in ‘gang’ activities. This finding,

again, demonstrates some support for the proposal that hostile aggressive drivers will

exhibit antisocial tendencies. Also, as gang membership can be conceptualised as a

way in which to enhance or develop feelings of belonging and identity (NCV, 1990),

it can be viewed as a maladaptive coping style, supporting the proposal that the self-

confessed hostile aggressive drivers will exhibit higher levels of maladaptive coping.

Additionally, the majority of participants reported associating with generally

‘less than positive’ peer groups during their adolescence. These peers came to the

attention of authorities to varying degrees. Thus the association of these participants

with peer groups that behaved in such a manner as to attract the attention of police,

shows partial support for the proposal that hostile aggressive drivers may have had

more close encounters with law enforcement officials than the general population.

As the findings of the National Committee on Violence (NCV, 1990) suggest,

perhaps involvement in such groups provides a refuge for such troubled youth, where

they were able to develop a sense of belonging and identity through participation in

delinquent behaviours.


The majority of participants reported having caused considerable trouble at

school, indicative of conduct problems. Four of these also reported regular truancy.

Although these transgressions occurred when they were adolescents, causing trouble

at school and truancy may be considered maladaptive styles of coping with problems.

Such problems have also been associated with later delinquency and aggression

(Hawkins et al., 1998; Farrington, 2002).

As exposure to the foregoing variables has been found to either directly or

indirectly influence delinquency and violence, participants were also asked if they

had ever incurred ‘off-road’ charges of any kind. Seven participants had amassed 18

‘other’ charges between them. These ranged through breaking and entering, assault

to attempted murder. A smaller proportion reported involvement in ‘bar fights’

which had not come to the attention of authorities. The number of charges associated

with physical assault or violence show support for the proposal that hostile

aggressive drivers may exhibit aggression/violence in other areas of their lives, may

have previously had close encounters with law enforcement officials, and may

exhibit antisocial tendencies. These results also appear to be consistent with the

problematic childhoods experienced by the participants (Appendix U) and literature

concerning the risk factors for aggression. Specifically, some human aggression

researchers have concluded that aggressive children tend to be aggressive teenagers,

who in turn become aggressive adults (McDonald & Brown, 1997).

Several of the participants had previously sought counselling for potentially

clinically diagnosable disorders i.e. depression, ADHD, Bi-polar Disorder and

Dissociative Identity Disorder. This rather high incidence rate of clinical disorders is

consistent with other research that found 80% of aggressive drivers in a sample of

30, had clinically diagnosable disorders (Galovski & Blanchard, 2002). Notably, six

participants expressed difficulty regulating their ‘anger’. However, considering the

hostile aggressive behavioural responses adopted by the case studies, perhaps all of

them may have such difficulties. Together, these results suggest that hostile

aggressive drivers are more likely to have emotional regulation difficulties. Once

again, however, this may in part reflect the fact that the participants were recruited

from a men’s health service.


6.4.4 Trait Person-Related Characteristics

The self-reported hostile aggressive driver group scored significantly higher

scores on the overall AQ and its four subscales than did the general drivers identified

in Study Two (n = 838) consistent with other traffic research (Deffenbacher, Oetting,

& Lynch, 1994; Lajunen & Parker, 2001). These results show support for the

proposal that hostile aggressive drivers have higher levels of trait aggression than

‘other’ general road users. Also, the fact that the hostile aggressive drivers in this

study had a significantly higher mean score for all but two AQ subscales (i.e. verbal

and hostile aggression) than the hostile aggressive drivers identified in Study Two (n

= 88), may be accounted for by the deliberate selection of highly aggressive drivers

for this study.

Consistent with the rational problem-solving results in Study Two (see Table

K4) the results of Study Three suggest that there is no significant difference in the

levels of ‘rational problem solving’ and ‘impulsive/careless style’ reported by hostile

aggressive drivers and the general driving population (n = 838) (Table 6.2).

However, the hostile aggressive driver group appear to have significantly higher

levels of negative problem orientation (NPO) than the general population of drivers

(n = 838) (Table 6.2). These results provide partial support for the proposal that

hostile aggressive drivers may have higher levels of maladaptive coping styles. As

effective problem solving has been found to mediate the level of stress experienced

by an aversive event (D’Zurilla & Nezu, 1999), hostile aggressive drivers appear to

be poor problem solvers. Indeed, they may be more negative in their approach to

problematic situations than the general driving population.

Examination of the BIS-11 subscale scores also showed partial support for

the proposal in Section 6.1.1 that ‘hostile aggressive drivers may be more likely to

engage in impulsive/reactive behaviours’. Comparison of individual subscale scores

with the subscale scores of a ‘general population’ (Muller et al., 2004) revealed some

statistically significant differences. CS1 and CS7 had significantly higher scores for

non-planning impulsivity, whilst CS1, CS4 and CS6 scored significantly higher on

cognitive impulsivity than the ‘general population’.

However, when the total BIS-11 scores were considered, the hostile

aggressive driver group did not significantly differ from the male ‘inmate’ or female

‘general psychiatric’ comparison groups, where considerably high impulsivity levels

were apparent (Patton, Stanford, & Barratt, 1995). Nonetheless, it would appear that


hostile aggressive drivers may have higher overall levels of trait impulsivity than

‘other drivers’.

6.4.5 General Psychological Characteristics

The following discussion of the general psychological characteristics of the

10 case studies and their psychological typing is based on the reported findings from

administration of the CPS (Carlson, 1982).

Individual participant chemical abuse scores were compared with the

published mean for an incarcerated group. Note that the CPS is normally

administered on intake to the prison system, therefore questions relating to chemical

abuse refer to the inmates ‘normal’ drug and alcohol intake prior to incarceration

(Carlson, 1982). There were no significant differences between the hostile

aggressive driver group and the comparison group, except for CS2 who reported

significantly higher levels of drug/alcohol intake. This result supports the proposal

that hostile aggressive drivers may be more likely to exhibit signs of drug and/or

alcohol abuse. Alcohol has been associated with increased rates of aggression and

violent crime (McDonald & Brown, 1997; Taylor & Hulsizer, 1998). Additionally,

other research indicates that aggressive drivers are more frequently diagnosed with

alcohol abuse (Galovski & Blanchard, 2002).

Further, research into the motivations for alcohol consumption suggests that

the high levels of NPO and ICS evident in this driver group may be associated with

an inability to ‘cope’ in the absence of other constructive/adaptive ways of coping.

Motivation for alcohol consumption has also been found to be strongly associated

with negative emotionality (as measured by levels of depression) (Cooper et al.,

1995). Therefore, as the majority of participants have at some time experienced

problematic alcohol consumption, perhaps this is also a reflection of their inability to

appropriately regulate their emotions consistent with the proposal in Section 6.1.1.

Examination of the ‘thought disturbance’ results as measured by the CPS,

demonstrated that hostile aggressive drivers may have higher levels of ‘distorted

thinking’ than the population in general. Only one case study (CS4) reported a

significantly higher score on levels of thought disturbance and validity than the

reference group. This was anticipated in light of his previous diagnosis with

Dissociative Identity Disorder. There were no other significant differences on the


levels of thought disturbance and validity between participant scores and the

reference group (i.e. an inmate population).

Individual responses to CPS questions relating to thought disturbance

suggested that the hostile aggressive driver in this sample is sometimes ‘a little down

some of the time’ to ‘sad a lot of the time’. These hostile aggressive drivers are also

likely to change from ‘happy one minute to sad the next’ from ‘some’ to ‘all of the

time’, suggestive of a susceptibility to sudden mood changes. Further, this driver is

likely to have ‘seen or heard things that were not there’, more than once or twice

(Carlson, 1982).

CS2 scored higher on antisocial tendencies than did the ‘inmate’ population

(Carlson, 1982). However, there were no other significant differences between the

hostile aggressive driver group and the reference group, demonstrating support for

the proposal that hostile aggressive drivers may exhibit higher levels of antisocial

tendencies. Thus, it would appear that hostile aggressive drivers may exhibit some

or all of the antisocial behaviours explored within the CPS questions including verbal

abuse, a degree of enjoyment for ‘fighting’, a preparedness to engage in physical

fighting, and carrying a weapon (refer to Questions 6, 9, 24, 28, 37 and 50 of the

CPS at Appendix N). Further, the increased availability of weapons and the higher

levels of trait aggression apparent in this group highlights the potential for extreme

violence (Miller, Azrael, Hemenway & Solop, 2002) (see individual case studies at

Appendix V). In addition, the AT scores and the self-reported histories of other

charges and offences outlined above supports Elliott’s (1999) viewpoint that ‘road

rage’ is a product of pre-existing criminal or anti-social tendencies.

When queried about the ‘illegal things’ that they have done, few felt ‘sorry’.

This suggests that this group may have little remorse associated with their anti-social

behaviours. Certainly, this lack of remorse is reflected in their individual case

studies as hostile aggressive drivers (Appendix W). Further, these drivers indicated

through their responses, that they would be less likely to ‘forget’ wrongdoings and

more likely to hold a ‘grudge’.

No significant difference was found between the hostile aggressive driver

group and the ‘inmate’ reference group on levels of self-deprecation. This result

suggests that either at trait or state level, the hostile aggressive driver degrades or

belittles himself to a similar degree to what would be expected in an ‘inmate’

population. Further, in the extreme, he may not value himself or his


accomplishments, reflecting despondency and/or depression. The result is also

consistent with the number of subjects noted to have sought counselling for

depression and other diagnosed disorders. The higher levels of SD may result in

increased irritability in the face of provocation (Stanford et al., 1995).

If ‘self-deprecation’ is loosely considered a measure of ‘negative

emotionality’ (Cooper et al., 1995), these results are also consistent with the

foregoing findings that demonstrate high levels of chemical abuse by the hostile

aggressive driver. These results also suggest that hostile aggressive drivers may

indeed experience difficulty managing their emotions.

Of the 18 different profiles or types offered by the CPS (Carlson, 1982),

seven of the hostile aggressive drivers were classified Type 5 – ‘markedly anti-

social’. Two were classified Type 16 – ‘negative/explosive’, and one was classified

Type 13 – ‘self-centered’.

Interestingly, across the descriptors for the three types identified there exist

several consistent themes. First, all three types focus on the inability of these

individuals to regulate their emotional expression and behavioural responses. Where

Type 13 (‘self-centred’) experiences ‘impulse’ control difficulties, Type 16

(‘negative/explosive’) is described as ‘short-tempered and explosive’. As Type 5,

the majority of participants in the case study analysis are ‘intolerant, hostile,

aggressive’ and ‘impulsive’. These characteristics were repeatedly evident in the

individual recounting of their experience with aggressive driving in the role of the

perpetrator. Further, such difficulties with ‘anger’ regulation or ‘impulsivity’, have

been associated with earlier research into aggressive driving behaviour (Fong, Frost,

& Stansfeld, 2001; Galovski & Blanchard, 2002b; Lajunen et al., 1999; Malta,

Blanchard, & Freidenberg, 2005).

Secondly, in keeping with some of this earlier research, the case study

participants also reported past and/or present difficulties with alcohol consumption

(see Appendix W) (Malta et al., 2005). Though some of the reported individual

scores may seem low in comparison to the mean for the incarcerated group, during

the interview most participants indicated that their drinking habits have changed over

time. By way of explanation, some suggested that they now had a reduced capacity

to drink due to either current medication or a reduced physical capacity (i.e. having

only one kidney). In some cases, underreporting was suspected. It was clear,


however, that all participants had, for some period in their lives, experienced

problematic alcohol consumption.

Finally, all but two of the case study participants reported marginally higher

mean scores on anti-social tendencies than the mean of the inmate population (refer

to Appendix T). One participant scored significantly higher on anti-social tendencies

than the comparison group (i.e. CS2, as outlined above). As the comparison group of

inmates are understood to have high levels of anti-social tendencies than the rest of

the general population, the trend of these results would suggest that hostile

aggressive drivers may possess relatively high levels of anti-social tendencies.

Further, such tendencies appear to extend beyond the on-road environment.

6.4.6 Hostile Aggressive Drivers and the Theoretical Framework of Aggressive

Driving

Both the quantitative and qualitative results indicate that there may be some

distinct differences between hostile aggressive drivers and the general driving

population on state and trait, person-related factors. These differences will be

highlighted in the following discussion of how effectively the GAM derived factors

proposed in the theoretical framework at Figure 4.3 apply to the hostile aggressive

driver group.

State and trait person-related factors appear to contribute to the ‘present

internal state’ that the hostile aggressive driver brings to the on-road environment.

The previous two studies support this suggestion, however, for the hostile aggressive

driver there appear to be some differences. The ‘present internal state’ brought to the

on-road environment by these drivers appears to be more negatively influenced by

off-road generated stressors, such as suggested by their complex psychological

backgrounds (Appendix V). Thus, this would reflect support for the Study Three

findings, that hostile aggressive drivers have higher NPO and ICS than general road

users. As such, when faced with stress these drivers may more readily adopt their

maladaptive coping styles and negativity. At the trait level, as many of the drivers

reported having experienced considerable difficulty with alcohol abuse at sometime

throughout their lives, these drivers may also have higher levels of negative

emotionality as a general state of being. Although negative emotionality was not

directly measured, previous research supports this concept, having found evidence of


a strong relationship between alcohol consumption and depression (Cooper et al.,

1995).

As a result of the state stress experienced by these drivers, they may also

bring to the on-road environment heightened levels of arousal. As illustrated in CS4

and CS8 (Appendix U), both case studies were markedly affected by their off-road

generated stress that would have elevated their physiological arousal levels. This is

consistent with research that would suggest such heightened levels of arousal has

been found to increase the likelihood of aggressive behaviour (Geen, 1990;

Zillmann, 1988). However, this finding is contrary to the suggestion emerging from

Study One that heightened arousal caused by less stressful events such as ‘cruising’

with friends may lead directly to aggressive on-road behaviour in the absence of a

provocative event. Therefore, perhaps aggressive driving caused by heightened

arousal of this nature applies more to ‘young drivers’ when they engage in on-road

behaviours that in themselves are highly aggressive or dangerous, such as excessive

speeding or ‘hooning’ consistent with Study One. Alternatively, the self-reported

hostile aggressive drivers of this study may be prone to readily interpret ambiguous

situations with high levels of aggression consistent with previous human aggression

research (Anderson et al., 1998; Berkowitz, 1989, 1990; Dodge & Coie, 1987).

Comparing the young driver research from Study One with these findings

confirms the impression that aggressive drivers engage in on-road aggression in one

of the two ways suggested earlier: by using a vehicle and the on-road environment as

a means of expressing off-road generated aggression; and/or, whilst driving, by

responding to provocative triggers that are encountered in the on-road environment.

When exposed to ‘other driver’ behaviours, the results indicate that the

hostile aggressive driver will initially, and more readily, perceive the ‘other driver’

behaviour as aggressive and deliberate, than will the general driving population.

Consistent with the theoretical framework proposed earlier (Figure 4.3) and the

human aggression literature, the initial response of the hostile aggressive driver to the

perceived provocation will comprise three elements: emotions, arousal and

cognitions. The order in which these elements occur cannot be distinguished, rather

they are considered to have an interactive, triadic relationship (Anderson &

Bushman, 2002; Berkowitz, 1993). As such, they are discussed below in no

particular order.


The results indicate that the hostile aggressive driver may be more likely than

‘others’ to assume knowledge of a negative attitude on the part of the ‘other driver’.

Consistent with the findings of Studies One and Two, the hostile aggressive driver

may make strong negative attributions about the ‘other driver’. An observation

unique to this study is that hostile aggressive drivers may appear more likely to have

thoughts of negative actions to adopt, potentially increasing the likelihood of an

aggressive response (Berkowitz, 1993; Berkowitz, 1989). Further, it was observed

that a number of the case studies had difficulty recalling aspects of the incident. In

the main, they were able to recall ‘pieces’ of the event clearly, but at times

demonstrated difficulty with recalling some thoughts and feelings.

Like many in the general driving population, the hostile aggressive driver

experiences anger, and sometimes fear or excitement. However, the difference

between these groups appears to exist in the intensity of the emotion experienced.

The hostile aggressive drivers in Study Three appear to experience intense levels of

anger, rage or excitement, in response to a perceived on-road provocation. The

results of this study are consistent with other research (Geen, 1990; Zillmann, 1988)

which suggests that the hostile aggressive driver will be more likely to experience

heightened physiological arousal in conjunction with these intense emotions.

As a consequence of the hostile aggressive driver’s emotional and cognitive

response, there appears to be little or no conscious weighing up of consequences

attached to the behaviours adopted, consistent with Study One findings. Rather, the

hostile aggressive driver behavioural responses described by participants appear to

have been quite deliberate due to the vengeful thoughts associated with the

behaviour. Further, participant NPO and ICS scores are also consistent with their

impulsive or deliberate retaliations to provocation.

Study Three results indicate that the hostile aggressive driver also appears

more likely to readily adopt instrumental aggression in response to perceived

provocation, such as finger gestures, verbal abuse and horn-honking. However, they

are also more likely than the general driving population to adopt hostile aggressive

driving behaviours. There is a higher chance that they will ‘follow’ or ‘pursue’ the

‘other driver’. They are also more likely to remove themselves from their vehicle in

order to engage physically or verbally with those drivers. If physical aggression is

adopted by this type of driver, it is usually in an extreme form that may result in

injury.


There is also a greater chance that they may cause damage to the ‘other

driver’s’ vehicle as a result of their intense emotions. For example, they may get out

of the vehicle and set upon the ‘other driver’s’ vehicle, or deliberately cause a

collision. The results of this study and Study Two illustrate that the factors that

determine the type of behavioural response exists at the trait and state person-related

level.

Contrary to Study Two, only two of the hostile aggressive driver group

reported having any ‘post-event’ influence as a result of the incident. Instead, the

majority gave the incident little or no thought shortly afterwards, potentially

indicative of a lack of remorse. Although a post-event influence does occur in some

instances, perhaps it does not add much to our understanding of the on-road

phenomenon of aggressive driving.

6.4.7 Strengths and Limitations of the Research

Although qualitative and quantitative methods were utilised in the conduct of

this study, the sample size was relatively small for quantitative purposes.

Nonetheless, for clinical case study purposes, the sample size of 10 is arguably

adequate as within the fields of clinical psychology a single case study is widely

accepted as valuable research that allows the in-depth examination of a particular

phenomenon and/or psychological disorder (Aaron & Aaron, 1999). This research is

often seen as a valuable precursor to other more statistically rigorous research in such

areas (Aron & Aron, 1999). A main strength of this study is that the design was again

driven by the human aggression theories contained within the GAM (Anderson &

Bushman, 2002). The first part of the study focussed on key psychosocial and

developmental factors that have been found to increase the likelihood of aggressive

behaviours both on and off-road (Chapters Two and Three). The latter, qualitative,

part of the study focused on exploration of the proposed theoretical framework of

aggressive driving (Figure 4.3) based on the GAM and Study One findings.

This research has provided insight into the person-related differences

between the self-confessed hostile aggressive driver and the general driving

population. These include insights into age, cognitions and emotions associated with

the event and the general attitudes of the hostile aggressive driver. Notwithstanding,

the results should be treated with caution as much of the data was ‘self-reported’ by

individuals essentially selected for anti-social behaviour.


The findings of this research would suggest that policing strategies may be

problematic, as many of the differences between hostile aggressive drivers and ‘other

drivers’ exist at the person-related level. Although we have moved towards a better

understanding of the characteristics of a hostile aggressive driver, the majority of

them are not observable to external parties. Therefore, although the findings of this

study may not directly assist the policing of this illegal behaviour, the research offers

considerable information on the factors that may need to be addressed in court-

referred, individual, interventions. Additionally, in a modified form, this information

may serve to reduce aggressive driving behaviour, if included in driver education and

rehabilitation programs.

The final limitation that should be given consideration is the manner in which the

participants were recruited. Nine of the 10 participants were recruited via MISA,

where seven of these individuals were attending counselling for a variety of personal

issues. Given the fact that participants were seeking support at MISA for a variety of

reasons, including anger management in some instances, the method of recruitment

must be considered a potential confound for some of the findings contained within

the study.

As previously mentioned, use of such a small and non-random sample

prevented the generalisation of results to the wider population of hostile aggressive

drivers. However, the nature of the sample allowed the exploration of individuals

with potential anger issues and whether they are likely to transfer their anger

management difficulties to the on-road environment. Hence, the study provides

potentially useful information to aid in understanding the hostile aggressive driver.

Further, this study may assist in the design of larger, controlled studies into the

characteristics of hostile aggressive drivers.

6.4.8 Recommendations for Future Research

The qualitative findings of this research would benefit from confirmation by

quantitative methods. For instance, more research is required into the attitudes of

hostile aggressive drivers. Also, closer examination of the incidence of

psychological disorders in this group of drivers is also warranted.

This body of work has detailed the phenomenon of aggressive driving in such

a way that may assist the further development of existing preventative and direct

intervention approaches to aggressive driving. Specifically, the research may inform


the refinement of counselling programs for court-referred aggressive drivers and

assist in the development of suitable education modules that may be included in

existing driver education programs. Therefore, the development and testing of a

module to augment existing driver education programs based on this research is

recommended.

A final limitation of this research is that it does not account for biological or

neuropsychological factors that have been found to contribute to an individual’s

predisposition for aggression, as acknowledged earlier in Chapter Three (p. 62).

Therefore, it is recommended that research into these factors be conducted in the

future.


As in Study Two, this study highlighted the significance and applicability of

the proposed theoretical framework for aggressive driving (Figure 4.3) to hostile

aggressive drivers. From the perspective of the hostile aggressive driver, the study

demonstrated the psychological elements and processes associated with this extreme

behaviour. This study also highlighted the significance of state and trait person-

related factors that appear to increase the likelihood of hostile aggressive driving

behaviour on the roads.

Further, examination of hostile aggressive driver exposure to a number of

developmental risk factors known to increase the likelihood of aggressive behaviour

in any context suggests that hostile aggressive drivers may have come from difficult

or dysfunctional backgrounds that the existing literature suggests increases the

likelihood of adopting hostile behaviours on the roads. The findings also suggested

that the hostile aggressive driver is more likely to have a history of anti-social

behaviours on and off-road.

In summary, the findings of this study have provided information about the

psychological characteristics of a sample of hostile aggressive drivers and the

psychological processes that are involved in the behaviour. As such, the results may

contribute to the further development of existing counselling and educational

interventions and contribute towards increasing the knowledge base of law

enforcement officials about the hostile aggressive driver.


Chapter Seven: Discussion

7.1 Discussion ....................................................................................................... 307 7.2 Review of Findings ......................................................................................... 307 7.3 Review of the Provisional Definition ............................................................. 315 7.4 Theoretical Implications ................................................................................. 316 7.5 Implications for Road Safety .......................................................................... 318 7.5.1 Public Intervention Implications ...................................................... 319 7.5.2 Targeting Young Drivers .................................................................. 320 7.5.3 Targeting Professional Drivers ......................................................... 321 7.5.4 Targeting Convicted Aggressive Drivers ......................................... 321 7.5.5 Evaluation of Strategies .................................................................... 322 7.5.6 Penalties and Sanctions Associated with Aggressive Driving ......... 323 7.6 Strengths and Limitations of the Research ..................................................... 323 7.7 Recommendations for Future Research .......................................................... 325 7.8 Concluding Remarks ...................................................................................... 326



7.1 Introduction

This research program has explored the psychosocial factors influencing

aggressive driving behaviour on Queensland roads, therefore providing insight into

the psychological and social nature of aggressive driving. The findings have also

shed light on the person-related and socio-demographic characteristics of those

drivers that are more likely to participate in both instrumental and hostile acts of on-

road aggression.

In this chapter the key findings from the research program will be brought

together, in order to consider the possible theoretical and policy implications. The

findings will also be discussed from the perspective of the GAM theory of human

aggression emphasising the relative contribution of the findings to our understanding

of the phenomenon.

The following review of the main findings of the three studies will be

discussed in terms of the key research questions. The remainder of the chapter will

focus on both the theoretical implications of the findings and their applied relevance

to road safety policy and practice.

7.2 Review of Findings

RQ1 What are the person-related and situational factors contributing to

aggressive driving?

Study One focus group findings highlighted many person-related and

situational factors that young drivers, identified as an at-risk group, believe

contribute to aggressive driving behaviour (refer to Figure 4.2). Among the person-

related factors, the findings confirmed earlier research that a driver’s state related

characteristics such as mood, job stress, life stress and driving stress impact upon

their driving behaviour (Hartley & Hassani, 1994; Hennessy & Wiesenthal, 1997;

Matthews et al., 1998; Simon & Corbett, 1996). Specifically, it would appear that

higher levels of these state characteristics will increase the likelihood of an on-road

aggressive response to perceived provocation.

Some of the trait-related factors identified in Study One such as age and

gender have previously been found to influence the likelihood of aggressive driving

behaviour (Aberg & Rimmo, 1998; Harding et al., 1998; Lajunen & Parker, 2001;

Lawton & Nutter, 2002; Shinar, 1998; VCCAV, 1999). Study Two findings also

emphasised the statistical significance of trait, person-related characteristics such as


age, gender and problem-solving styles in instrumental and hostile aggressive driving

outcomes. However, personality and driver attitudes associated with aggressive

driving have been explored to a lesser degree in previous research. With reference to

personality, much of the existing research into these factors has focused on specific

facets of personality, such as trait aggression and impulsivity levels (Deffenbacher et

al., 2003; Karli, 1991; Lajunen & Parker, 2001). The discussion of the findings

relating to the personality of drivers more likely to engage in hostile on-road

aggression is outlined under the sixth, and final, research question.

Existing research into driver attitudes and their potential to influence

aggressive driving behaviour has previously focussed on ‘driver vengeance’

(Hennessy & Wiesenthal, 2002). However, this research program suggests that

although driver ‘vengefulness’ would appear to contribute to aggressive driving,

more can be understood about the phenomenon if the source and development of

such negative driver attitudes and stereotypes are identified and explored. In

particular, the focus group findings suggest that through exposure to less than

positive ‘prior learning’ experiences (i.e. social learning) a driver may be more likely

to develop negative attitudes and stereotypes that increase the likelihood of

aggressive driving behaviour. This possibility was further suggested by the finding

of Study Three which indicated that hostile aggressive drivers are more likely to

originate from dysfunctional, even problematic, childhoods.

The situational factors contributing to aggressive driving that were identified

in the program of research appeared to fall into two main categories: facilitating

factors and the observed, on-road behaviour of ‘others’. As facilitating factors,

participants identified the indirect factors that they believe contribute to the

likelihood of aggressive driving behaviour. Notably, several of the factors identified

by the young driver participants in Study One have not previously been associated

with aggressive driving, such as driving with peers as passengers, music, vehicle

appearance and mechanical modifications.

The focus group participants also identified multiple behaviours that they

believe directly contribute to episodes of aggressive driving behaviour. All of these

behaviours have been frequently cited as common triggers in aggressive driving

research (refer to Chapter Two). Admittedly, however, these behaviours may be

perceived by some drivers as mere errors in judgement. As such, the participant


identification of these behaviours emphasises the importance of ‘perception’ in

aggressive driving.

In Study One, the reported behavioural responses of the young driver group

to perceived on or off-road provocation ranged from verbalising under one’s breath

to tailgating, following closely and other risky behaviours that can contribute to crash

involvement. In Study Two, participants were asked to nominate the likelihood of

their adopting the behaviours nominated in the behavioural response set constructed

from Study One findings and the work of Lajunen and colleagues (1999). Many of

these participants indicated a preparedness to engage in instrumental aggression,

whilst n = 88 of the participants were unable to rule out the possibility of adopting

hostile aggressive behaviours in response to a provocative or ambiguous on-road

incident. Hence, both studies suggest that hostile aggressive driving behaviour is

more likely to occur among a relatively small group of drivers. However, the

indication that a considerable proportion of drivers are prepared to engage in

instrumental on-road aggression is of concern, especially as instrumental behaviours

may lead to the escalation of an on-road conflict particularly where one of the drivers

has a higher trait potential for hostile aggression.

The use of two scenarios, an overtly provocative incident (Scenario One) and

an ambiguously provocative incident (Scenario Two), also demonstrated the

potential contribution of on-road situational factors to the likelihood of emotional,

cognitive and behavioural responses. In a clearly provocative on-road incident,

drivers are more likely to experience frustration, anger, threat and negative thoughts.

Further, they are more likely to adopt either an instrumental or hostile behavioural

response to such provocation than when faced with an ambiguous on-road situation.

Hostile drivers identified in Study Two (n=88), however, are more likely to

experience more frustration, anger, threat and negative thoughts in either on-road

situation. These drivers are also more likely to adopt both instrumental or hostile

aggressive behaviours in response to either situation, again highlighting the role of

person-related factors in aggressive driving.

RQ2 Are some drivers more likely to engage in aggressive driving and, if so,

what are their characteristics?

In general, the focus group research and Study Two findings would suggest

that a large proportion of drivers are prepared to engage in some form of

instrumental on-road aggression given sufficient on-road provocation and the right


contextual circumstances. Interestingly, in the results of the young driver study

(Study One), young females appear to be increasingly prepared to engage in on-road

aggression than previously reported in the literature review (VCCAV, 1999).

Specifically, more than half of the participants in the study who reportedly

participated in outward expressions of on-road aggression were female (16 females

and 14 males). However, it was found in Study Two that male drivers were

statistically more likely to engage in both instrumental and hostile aggressive

behaviour than female drivers. Interestingly, in the potentially hostile aggressive

driver group (n = 88) identified in Study Two a wide age range was evident.

Although young drivers 17–24 years of age were significantly more likely to be

identified as potentially hostile aggressive (refer to Table 5.2), the regression

analyses did not reveal age to be a significant predictor of the likelihood of a hostile

aggressive behavioural response to either Scenario One or Two (refer to Section

5.3.8.3.2). These results would suggest that hostile aggressive driving behaviour is

not exclusive to the young driver group.

So what are the characteristics of those drivers that are more prepared to

engage in hostile aggressive driving? The second phase of Study Two did not reveal

any statistically significant socio-demographic differences between the participants

classified as hostile aggressive drivers (n = 88) and the ‘other driver’ group (n =

838). Between these driver groups there were no significant differences in terms of

reported levels of education, hours driven per week, type of vehicle, crash

involvement, or the number of speeding and other fines in the past three years.

However, several trait person-related factors were identified as having a significant

influence upon the likelihood of being categorised as a hostile aggressive driver.

The drivers that were more prepared to engage in hostile aggression on the

roads (n = 88) were significantly higher in trait aggression and negative/impulsive

problem-solving styles than the ‘other driver’ group (n = 838). When faced with a

potentially anger-provoking scenario these drivers experienced significantly more

negative emotion and perceived threat. They were also more likely to have negative

attributions about the ‘other driver’. In turn, they were more likely to respond to on-

road provocation with more instrumental aggression and hostile aggression than

those in the ‘other driver’ group. The self-report measures used also indicate that

these drivers were more likely to engage in speeding behaviours on urban roads or

highways and were more likely to drink/drug drive. These self-reported behaviours


may be indicative of the potentially hostile aggressive driver possessing underlying

anti-social tendencies, not normally found in the general road user.

The foregoing evidence would suggest that person-related characteristics

appear to have a greater overall influence upon the likelihood of aggressive driving

than the on-road situational triggers. Therefore, Study Three explored the person-

related characteristics of self-reported hostile aggressive drivers in greater detail.

Study Three confirmed the significance of several person-related factors and

suggested various risk factors for the development of aggressive tendencies that

increase the likelihood of extreme on-road aggression. These findings will be

discussed in greater detail under RQ6.

RQ3 Is it appropriate to conceptualise aggressive driving as a continuum of

related behaviours?


These research questions will be addressed concurrently. In Study Two, the

factor analysis of the behavioural response items suggested the existence of two

distinct but related factors, which were later termed instrumental and hostile

behaviours consistent with earlier research (Shinar, 1988). The instrumental

behaviours included: swearing/muttering or shout out loud to yourself, gesturing at

the other driver, use of a car horn, flashing of lights, and driving close/following the

other driver. The hostile behaviours included: stopping the vehicle prepared to argue

or physically engage the other driver and using your vehicle to damage the other

driver’s vehicle.

Adoption of instrumental behaviours would appear to serve a joint

frustration-relieving and practical purpose. Such behaviours are consistent with

trying to overcome an on-road obstacle, or source of delay, whilst some of the

behaviours also suggest a personal need to vent frustration or anger. However,

adoption of instrumental aggression, for either reason, does not necessarily lead to

hostile on-road behaviours. Therefore, instrumental aggression would appear to have

a frustration-relieving effect for some drivers (Dollard et al., 1939). Conversely, the

adoption of hostile aggressive behaviours on the road appears to serve less functional

purposes. These behaviours are frequently associated with high levels of negative

emotion and thoughts of retaliation. When such behaviours are adopted, in most

cases, the incident has escalated to involve some form of interpersonal contact. So

motivated, hostile aggressive drivers are more likely to deviate from their original


journey, (thus temporarily abandoning their original goal) in order to send a message

to the perceived ‘offending driver’. Therefore, these behaviours serve no immediate

practical purpose in terms of a person’s trip goals. Consistent with frustration-

aggression theory, however, these behaviours may also serve a cathartic effect

(Dollard et al., 1939), since many potentially hostile aggressive drivers in Study Two

and Three reporting little post-event influence, having given the matter very little

afterthought.

Given the scenarios presented to the participants in Study Two (particularly

the ambiguous Scenario Two), the adoption of hostile on-road behaviours could be

interpreted as an ‘over-reaction’. In this sense, drivers prepared to adopt hostile on-

road aggression would seem to have some difficulty regulating their responses.

Based on human aggression research into emotional regulation (Chang et al., 2003;

Cummings et al., 2004; Loeber et al., 2001), this difficulty may stem from their

inability to regulate the emotions they experience when faced with on-road

provocation. Similarly, this inability to regulate emotions and subsequent

behavioural responses may stem from high levels of trait impulsivity generally

observed as being more apparent in young drivers (Deffenbacher et al., 2003). Study

of the potentially hostile aggressive drivers in Chapter Five and the self-reported

aggressive drivers in Study Three, would suggest that such difficulties are deeply

person-related and developed across the course of one’s life experiences. For some

of these drivers the adoption of hostile aggressive behaviour seems to be impulsive.

Nonetheless, the decision to engage in hostile behaviours appears to be clearly

intentional, as suggested by Study Three findings.


driving behaviour?

The Study One exploration of potential contributing factors was guided by

the key elements in the original GAM (see Figure 4.1). In Study One, focus group

participants readily identified with these elements verifying the relevance of human

aggression theory to the phenomenon of aggressive driving. Focus group

participants identified how negative emotions prior to the on-road incident may have

influenced their driving behaviours. They also readily identified the negative

emotions they had during their recalled experience with aggressive driving, such as

annoyance, frustration, anger and fear. It also appeared that the more intense

experience of these negative emotions led to more aggressive on-road behaviours.


However, a few participants spoke of feeling ‘excited’ during the incident. This

feeling of excitation, and its association with aggressive driving, was later confirmed

in the final study examining self-reported hostile aggressive drivers.

Notably, when asked what thoughts they had during their personal

experiences with aggressive driving, not one focus group participant spoke of

conscious decision-making processes, suggesting a lack of deliberate thought

processes associated with aggressive driving behaviour. However, in Study Three

the self-reported hostile aggressive driver reported having thoughts of taking specific

actions, intended to harm and/or take revenge, against the ‘other driver’. Although it

is acknowledged that the participant responses were limited by their recall abilities, it

does appear that conscious decision making appears to be obscured, or blocked,

during aggressive driving incidents, particularly those of a more hostile nature.

Indeed, perhaps the adoption of either instrumental or hostile behaviours is more

dependent on problem-solving abilities as suggested by the findings of Study’s Two

and Three. In Study Two the hierarchical regression analyses illustrated that

significance of problem-solving style as measured by SPSI-R subtests (NPO, ICS,

and RPS) in the likelihood of instrument and hostile behavioural outcomes. Further,

Study Three results also suggested that NPO style as measured by the SPSI-R is

more prevalent among self-confessed hostile aggressive drivers.

Following an aggressive driving incident, some young drivers in Study One

reported the continuation of emotions and thoughts of the incident for a short period

of time. However, the transfer of these thoughts and emotions to subsequent driving

behaviour and off-road environments appeared to have little impact upon their

subsequent behaviours.



who report only engaging in instrumental acts of aggressive driving?

Study Three examined the person-related characteristics of self-confessed

hostile aggressive drivers in considerable depth. These drivers appear to differ

significantly on a range of person-related characteristics from the general driving

population. Similar to the Study Two examination of potentially hostile aggressive

drivers (n = 88), Study Three self-reported hostile aggressive driver ages ranged from

24 to 55 years of age (M = 41.6 years). However, male drivers were more prevalent

than females in the hostile aggressive drivers identified in both Studies Two and


Three. The majority of participants in Study Three were married/defacto and had

reportedly completed Year 10 or better. The income of six of the drivers ranged

from $31,000 to $70,000 per annum.

Many of the Study Three participants also reported over 20 years’ driving

experience and driving most frequently on city/suburban roads. Consistent with the

findings in Study Two, the hostile aggressive drivers identified in this albeit small

study are also more likely to drive a medium to large vehicle. Additionally, the

hostile aggressive driver in the Study Three sample was found to be more likely to

have a history of driving offences such as speeding, drink-driving, driving unlicensed

and/or dangerous driving. The hostile aggressive driver in the sample was also more

likely to have a history of violence or delinquency in his earlier life.

Study Three drivers were also found to have higher than average trait

aggression and negative or impulsive/careless problem-solving styles than the

general driving population identified in Study Two (n = 838). Further, when

compared to the hostile aggressive drivers identified in Study Two (n = 88), they

again scored significantly higher on both characteristics. However, these results

need to be interpreted with caution due to the small and selective nature of the

sample used in Study Three.

In terms of personality, the Study Three drivers were found to have

statistically similar levels of chemical abuse, thought disturbance, anti-social

tendencies and self-depreciation to those in the comparison sample of incarcerated

individuals (Carlson, 1982). Also their impulsivity levels, as measured by the BIS-

11, did not significantly differ from the male ‘inmate’ or female ‘general psychiatric’

comparison groups, where considerably high impulsivity levels were apparent

(Patton et al., 1995).

Using the SLEs to explore life experience and prior exposure to trauma or

violence, the study showed that the individuals in the sample were more likely to

have come from dysfunctional families characterised by difficult childhoods. The

types of difficulties identified include child abuse/neglect, association with less than

positive peers, youthful exposure to law enforcement, parental alcohol abuse and

poor familial attitudes to school and authority. Not surprisingly, therefore, a

considerable number of the participants in Study Three had reportedly sought

counselling for a range of potential disorders ranging from depression through to


dissociative identity disorder. Many of these individuals also expressed difficulty in

controlling their anger in other areas of their lives.

The results of Studies Two and Three would suggest that in response to

particular on-road situations the hostile aggressive driver will more readily interpret

‘other driver’ behaviour as threatening, aggressive or antagonistic. They would

appear to be more likely to experience stronger negative emotions and more negative

attributions together with thoughts of taking action against the ‘other driver’. In

Study Three, the self-reported experiences of the participants suggest that the

perceived attitude of the ‘other driver’ appeared to be an important catalyst for the

hostile aggressive driver response. Furthermore, these self-confessed hostile drivers

not only responded with greater levels of aggression or violence, but were prepared

to deviate from their journey and follow an ‘offending driver’ in order to right a

perceived wrong.

7.3 Review of the Provisional Definition

“Aggressive driving is any on-road behaviour adopted by a driver that is

intended to cause physical or psychological harm to another road user and

is associated with feelings of frustration, anger or threat.”

The above definition, used throughout this research (Section 2.2.5.3), was

constructed from the three primary themes identified in previous attempts at defining

aggressive driving i.e. emotion, behaviour and intent (Dula & Geller, 2003). For the

purpose of this research the definition has proved most useful. The definition

allowed the broad exploration of a wide variety of emotions that this research has

found to be associated with aggressive driving behaviour, namely frustration, varying

degrees of anger, and feelings of threat.

Using an exploratory approach, Studies One and Three identified a wide

range of on-road behaviours that may be classified as aggressive from the

perspective of young drivers and self-reported hostile aggressive drivers respectively

(Figure 4.2 and Section 6.3.6). In Study One, allowing for a third party assessment

of driver behaviour as ‘threatening or intimidating’ facilitated the identification of a

large number of behaviours that may be considered aggressive to general road users.

Consistent with the definition, these behaviours appeared to be identified as

aggressive because of the degree of ‘intentionality’ that is perceived to be associated

with the adoption of such behaviours on the road.


For the purpose of aggressive driving research, levels of ‘intentionality’

detected in response to exposure to real-time on-road triggers is difficult to ascertain,

as evidenced in Studies One and Three. Notwithstanding, Studies Two and Three

findings suggest that the on-road behaviour of the more hostile aggressive drivers is

often deliberate. Therefore, this definition has proven quite robust for the exploratory

examination of aggressive driving as a phenomenon, particularly from the

psychological perspective.

7.4 Theoretical Implications

Use of the GAM (Figure 3.1) facilitated the examination of aggressive

driving from a psychological perspective. Moreover, as the various components of

the GAM have been the subject of considerable research into human aggression in

other contexts, the theoretical framework was considerably robust (refer to Chapter

Three). A key contribution of the GAM was that it facilitated a detailed examination

of the three components of the ‘present internal state’ (see Figure 3.1): emotions,

cognitions and arousal associated with aggressive driving. Examination of these

interrelated components has provided empirical support for the use of CBT in the

counselling of identified serious offenders, as CBT focuses on changing behaviours

by addressing maladaptive or dysfunctional thinking. Similarly, it has provided

insights into how driver educational programs could be enhanced to target the issue

of aggressive driving.

Despite evidence of some recall difficulties noted in Studies One and Three,

the adoption of different aggressive driving behaviours appears indicative of either

impulsive or thoughtful behavioural responses consistent with the GAM (Figure 3.2).

Further, the concept of ‘cognitive resources’ was examined and found to be

important in determining the likelihood of a behavioural response. However, the

relationship between the concepts of ‘goal satisfaction’, ‘reappraisal’ and

behavioural outcomes as detailed in the model (Figure 3.2) was not explicitly

examined in this body of work and as a consequence, more research is required in

this area. Nonetheless, the findings of this research suggest that much of the thought

processes are largely subconscious and somewhat automated, and not easily retrieved

from the memory of road users. Also, Studies Two and Three findings suggested

that the hostile aggressive drivers tend to respond differently to on-road provocation

than other road users, particularly in ambiguous situations (i.e. Scenario Two). More


specifically, they appear to process on-road situational factors and potential triggers

for on-road aggression in different ways. Indeed, they also appear more likely to

respond impulsively. This finding is in keeping with the ‘impulsive’ behavioural

responses possible within the original GAM (Figure 3.1).

A number of findings in this research also support Shinar’s (1998)

frustration-aggression theory of aggressive driving. The person-related variables that

a driver brings to the on-road environment do appear to increase the likelihood of

aggressive behaviour on the roads. Shinar’s (1998) explanation of the

instrument/hostile distinction also warrants further research and clarification. His

distinction emphasised that the driver’s ‘path to goal is blocked’ precedes the

decision to respond with instrumental/hostile aggression. However, the results of

this research indicate that this process needs further consideration. The findings of

the current research suggest that it is whether a driver is prepared to abandon their

goal to engage in an aggressive action, which appears to characterise a hostile

behavioural response.

Furthermore, while the dichotomous, instrumental/hostile distinction made by

Shinar (1998) was supported by the factor loadings in Study Two, some of the

behaviours such as ‘muttering under one’s breath’ demands greater consideration as

to why they loaded onto each particular factor. As such, the results highlight the

need to better understand the function served by adopting these behaviours.

Another common theme emerging from the research is that aggressive

driving behaviour appears to serve an emotional function, although this relationship

is not at all clear. Also, in the case of hostile aggressive drivers, Shinar’s (1998)

suggested question of whether “aggression is possible or not” (Figure 2.3) seems

moot, as such drivers are likely to respond with aggression despite Shinar’s

suggested constraints (i.e. cultural norms and enforcement). Having considered the

behavioural factor loadings in Study Two, the adoption of instrumental behaviour

appears to be goal driven, in that the adopted behaviour will allow a driver to

continue with their original purpose for the journey. Alternatively, hostile

behaviours appear to require the abandoning of one’s goals in order to ‘right’ a

perceived ‘wrong’.

In addition, the research also found that aggressive driving behaviour is not

always frustration-aggression driven, differing slightly from Shinar’s theory (1998).


Consistent with the GAM, it was found that aggressive driving behaviour may also

involve feelings of excitation (Zillman, 1988).

Lastly, the findings suggest that person-related factors influence one’s

perception of ‘other driver’ behaviour as aggressive or benign. The use of the two

scenarios in Study Two highlighted this finding. Those drivers with a predisposition

for aggression were more likely to perceive aggression or ‘wrong doing’ in an

ambiguous on-road situation and respond with instrumental and/or hostile behaviour.

Therefore, there is a need to explore further the perceptual processes involved in

aggressive driving behaviour. A perceptual stage has not been included in either the

GAM or the Frustration Aggression Model (Anderson & Bushman, 2002; Shinar,

1998). Certainly, in terms of the GAM, a greater understanding of the way in which

drivers perceive their environment and potential provocation may assist in

understanding and addressing the behaviour of perpetrators.

7.5 Implications for Road Safety

This research has identified many important situational and person-related

characteristics associated with the expression of aggression on the road. In

particular, the person-related characteristics identified in the research add to the

psychological knowledge of the phenomenon. Though this knowledge may assist in

the formulation of strategies designed to reduce the incidence of aggressive driving,

the potential benefits from the implementation of such strategies are difficult to

quantify. At present, the current public liability or costs associated with aggressive

driving are difficult to quantify due to under-reporting (DCPC, 2005). However, the

AAMI report that potentially 50% of all insurance claims made in 1997 were due to

aggressive driving. Consequently, the potential financial savings to be made from

this research may be considerable. Notwithstanding, the potential physical and

psychological consequences of aggressive driving can still be severe, as illustrated by

some of the self-reported incidents outlined in this research program. As detailed in

Study Three (n = 10), five self-reported hostile aggressive drivers reported having

been fined for speeding and three for ‘unlicensed driving’. Though these drivers

reported few other on-road transgressions within the last three years, driving-related

charges outside of this period were quite extensive (see Appendix U) including

speeding, drink-driving, unlicensed driving, red light running, dangerous driving and

hooning among others. These findings suggest that those drivers more likely to


engage in hostile aggressive driving behaviour are likely to have a considerable

history of other on-road violations. These drivers appear to pose a significant road

safety risk, aside from their propensity to engage in acts of aggressive driving. This

suggests that innovative programs to target repeat offenders, such as vehicle

impoundment, may have ‘spill-over’ benefits for reducing aggressive driving.

Unfortunately, the situational and person-related characteristics identified by

this study do not render the hostile aggressive driver easier to visually identify for

policing purposes. Most of the key person-related characteristics of the driver more

prone to hostile aggression are contained within their personal psychology. As such,

if involved in an on-road incident drivers will remain largely unaware of the range of

behavioural responses possible from another driver. Despite this, the research has

provided a clearer picture of the psychological processes involved in aggressive

driving incidents. Therefore, a two-tiered approach to combating aggressive driving

is suggested by the research findings.

Firstly, for the general driving population it would seem appropriate to adopt

a preventative approach through education with the view to reducing the incidence of

aggressive driving. Secondly, for those drivers who come to the attention of the

courts for on-road aggression or dangerous driving, rehabilitation/counselling

programs warrant trialling, to establish whether they are effective in reducing repeat

offending. Thankfully, however, it would seem that severe expressions of on-road

aggression involving interpersonal violence are relatively rare, suggesting that it is

not an issue warranting the use of extensive road safety or public safety resources.

7.5.1 Public Intervention Implications

Public intervention strategies in this area need to involve the education of

general drivers about the possible dangers, costs and penalties associated with

aggressive driving behaviours. In particular, it would be appropriate to advise the

public that you never know the potential the ‘other driver’ has for hostile aggressive

driving behaviour. As a hostile aggressive response can be elicited by relatively

minor on-road transgressions, such as lapses in judgement or driving errors, it would

appear important to learn to diffuse potential incidents, preventing their escalation.

Therefore, informing participants on the action they can take to reduce the likelihood

of a provocative on-road incident escalating to a dangerous level is important. For

instance, due to the greater likelihood of the hostile aggressive driver interpreting


‘other driver’ behaviour as personal and deliberate, general drivers should be

instructed to avoid eye contact and deliberately adhere to ‘normal’ driving behaviour.

It would also appear prudent to inform a driver of protective behaviours they

may adopt should they feel threatened. For example, should a driver begin to fear

the consequences of an escalating incident they should not return to their home.

Rather, they should make their way to a more heavily populated area, such as a

service station or police station. Additionally, as other researchers have reported,

there are steps that can be taken by a driver to reduce their experience of on-road

stress, thereby possibly reducing the likelihood of aggressive driving (Deffenbacher

et al., 2002). Much of this information has the potential to be disseminated to the

general driving population through public education channels. However, young

drivers as a high-risk group should be specifically targeted through novice driver

education programs as a preventative measure.

Despite the potential severity of aggressive driving outcomes, many incidents

fail to come to the attention of law enforcement officials. Among those that are

reported, few are pursued, and less are prosecuted. Perhaps, it is the blurring of the

victim/perpetrator status that leads to a general reluctance, or apathy, to report such

incidents to authorities. For example, drivers may adopt on-road aggression in

response to ‘other driver’ aggression. Hence, reporting an incident to the police may

also require the reporting of one’s own on-road behaviour, a risk that some drivers

may not be willing to take. However, due to a reluctance to report aggressive driving

incidents, drivers inadvertently accept these behaviours and perhaps help perpetuate

the problem. For on-road aggression to be reduced, there needs to be social

consensus on the unacceptability of it. Therefore, Government agencies and law

enforcement, as community leaders, need to assert their non-acceptance of

aggressive on-road behaviours.

7.5.2 Targeting Young Drivers

Targeting young drivers within relevant education programs may enhance the

effectiveness of aggressive driving countermeasures by imparting the information at

a critical point in the licensing process. Delivery of relevant information at the pre-

licence and/or learner driver stage will increase driver knowledge of how to avoid

potentially aggressive on-road incidents prior to taking to the on-road environment

unsupervised. It would also serve to make these drivers more conscious of their own


on-road behaviours and perhaps increase self-monitoring behaviours. It may also

address ‘inappropriate’ perceptions regarding normative behaviour on the road.

Through existing driver education programs young drivers could be informed

of the range of situational and person-related factors that contribute to aggressive

driving. Further, these drivers could be informed about the psychology and

processes involved in on-road aggression. Particular emphasis should also be placed

on the perception of ‘other driver’ behaviours, stereotypes and attitudes and the

influence of these upon their own driving behaviour. They also need to be informed

of the possible psychological and physical consequences, as well as the penalties and

sanctions associated with aggressive driving. Although some drivers may have the

potential to over-react given such information, by raising driver knowledge of

aggressive driving and its potential for injury or property damage, it is possible that

many young drivers will adjust their driving behaviours.

7.5.3 Targeting Professional Drivers

By the nature of their profession, professional drivers are exposed to high

levels of both on and off-road generated stress. These drivers are often placed under

pressure to meet company deadlines and also subject to higher levels of on-road

stress due to the greater number of hours spent driving (Cartwright et al., 1996).

Fleet management experts have acknowledged that there is a high monetary cost

associated with vehicle damage resulting from crash involvement (Downs et al.,

1999). This would suggest that it may be cost effective to include the issue of driver

aggression in various fleet driver education initiatives. Alternatively, professional

drivers that operate independently, outside of a ‘fleet environment’, could be

educated through the provision of self-education materials via post or a website.

7.5.4 Targeting Convicted Aggressive Drivers

Driver rehabilitation through psychological counselling needs to be

considered for those drivers convicted by a court of on-road aggressive behaviours.

As the trait, person-related characteristics of these drivers are likely to be fraught

with emotional regulation difficulties stemming from their personal history and/or

psychology, individual counselling is recommended.

These drivers, identified as high-risk, could be educated about the multiple

factors that contribute to aggressive driving and the psychology of the phenomenon

as proposed above for young drivers (see Section 7.3.1). However, for these drivers,


the information needs to be elaborated upon and given personal relevance to the

offender and their driving behaviour. Finally, this research would suggest that such

drivers need to be introduced to alternative coping strategies for stress, both on and

off-road. Notably, the findings of Study Three suggest that it may also be necessary

to counsel these drivers on substance abuse issues.

Importantly, examining aggressive driving from within the framework of the

GAM (Anderson & Bushman, 2002), highlighted many components of aggression on

the road that are consistently emphasised in cognitive behaviour therapy, such as the

need to reduce the experience of on-road stress and enhance cognitive coping

strategies (Deffenbacher et al., 2002a). Therefore, a cognitive-behavioural approach

to therapy would seem appropriate for the rehabilitation process.

There are, however, some anticipated difficulties with the introduction of

such a program. Firstly, the Study Three findings suggest that the hostile aggressive

driver has little personal insight and lower than average levels of remorse, which

may contribute to a less than ideal result from counselling. Secondly, these drivers

may be unco-operative and less likely to actively participate in the counselling

process due to the fact that they have been required to attend counselling. Hence,

rehabilitation programs in this area would need to be carefully designed and

evaluated.

7.5.5 Evaluation of Strategies

As pointed out by the DCPC (2005) few initiatives aimed at reducing on-road

aggression have been properly evaluated, hence it is difficult to assess their

effectiveness. Therefore, further to the development and implementation of any

countermeasures outlined in Section 7.4 above, appropriate steps need to be taken to

ensure effective program evaluation. In the design of the educational materials

mentioned above, attention should be paid to the inclusion of program evaluation

criterion. From the outset, the intention should be to rigorously assess the quality

and effectiveness of the relevant training programs for young drivers, professional

drivers, the general driving population and court referred drivers. The professional

driver and court referred driver programs should also endeavour to measure changes

in driver behaviour three to six months after training or rehabilitation to assess

whether any relapse may have occurred. Further, all of the program evaluations


should also examine the overall effect of the program on aggressive driving rates and

related repeat offending.

7.5.6 Penalties and Sanctions Associated with Aggressive Driving

At present, in Queensland, certain behaviours that may be deemed by law

enforcement officials as ‘aggressive’, such as speeding and racing, attract the

penalties and sanctions laid down in the TORUM Act (1995). There is no specific

legislation relating to ‘aggressive driving’ per se. However, more severe on-road

incidents that result in the physical injury or death of another road user are dealt with

under the Criminal Code 1899.

As illustrated in CS8 and CS9 of Study Three, some on-road incidents that

escalate to physical violence between two drivers may be dealt with under s335 and

s340 i.e. ‘common assault’ or ‘serious assault’ respectively of the Criminal Code

1899. Other instances are dealt with under s328A ‘dangerous operation of a vehicle

(with or without aggravation)’. To be charged under s328A, the behaviours in

question need to be observed, or have specific outcomes, such as crash involvement.

Although no specific aggressive driving legislation exists, current Queensland laws

would appear sufficient to deal with aggressive driving behaviour in its many forms.

Arguably, therefore, any proposal to change to current legislation to accommodate

‘aggressive driving’ per se would not currently appear warranted.

Finally, whilst researchers may find the term ‘aggressive driving’ useful, the

use of terms like ‘road rage’ and ‘road violence’ by the media and public do not

appear to be constructive. Overuse of these terms could possibly add to the

perception of a new and growing societal problem. Therefore, use of the term ‘road

rage’, in particular, should be discouraged (Elliott, 1999).

7.6 Strengths and Limitations of the Research

This research program featured a number of strengths. The first strength is

the wide variety of methods used to examine the phenomenon. Study One explored

the phenomenon from a qualitative perspective, producing a large amount of

information about the nature and psychology of aggressive driving behaviour. Study

Two adopted a quantitative approach in order to examine these findings on a large

sample of Queensland drivers (n = 926). This data was then used to identify those

drivers that have a greater likelihood of hostile aggressive driving behaviour (n =


88). In Study Three, a case study approach was adopted to examine in greater detail

the psychosocial characteristics of self-confessed hostile aggressive drivers.

An additional strength was the theoretical foundations underpinning the

research. Use of the human aggression theories contained within the GAM

(Anderson & Bushman, 2002) throughout the three studies, provided a useful

framework for guiding the design of the research studies and for interpreting the

findings.

The final strength lies in the practical implications of this research. The

findings of each study may contribute to enhanced education and individual

rehabilitation programs discussed above or to inform further research. However, this

research program was not without its limitations. Although the specific limitations

of each study are outlined at the end of the relevant chapters, the following

limitations are summarised for ease of reference.

Study One did not endeavour to measure the state and trait characteristics of

the participants. Therefore, although the potentially hostile aggressive drivers

identified in Study Two were easy to identify by their reported behaviours, their

person-related characteristics were not explored in exhaustive depth. Additionally,

as Study One focused on young drivers the results of the study cannot be generalised

to the greater driving population. Finally, the Study One data was also obtained

primarily from ‘city’ drivers.

Study Two limitations stem primarily from methodological considerations.

Firstly, the use of scenarios lacks realism. Aggression research also shows that

participants tend to under-report on aggression measures and their likely responses to

scenarios (McCloskey & Coccaro, 2003). This is primarily due to the social

desirability bias, which maintains that people generally wish to present themselves in

a favourable light. The construct of the two scenarios may have also introduced a

potential confound to the findings. As outlined in Study Two, despite a pilot study,

Scenario Two included a contextual, off-road stress factor that may have influenced,

or added another layer of complexity to the findings.

An additional limitation of Study Two was the bi-modal distribution of the

age-groups represented in the sample (refer to Section 5.3.5.1). Despite targeting a

wide age range, the final sample yielded a bimodal distribution with more 17–24 and

40–59 year old drivers than other age groups, which may have influenced some of

the findings. Hence, the results should be interpreted with due caution.


Study Three needs to be replicated in a larger sample of self-reported hostile

aggressive Australian drivers to assess the validity of the findings. Also, as

previously stated, nine of these drivers were recruited through a local counselling

service (i.e. MISA) potentially confounding some of the findings. Additionally,

some of the key person-related characteristics of these drivers are themselves

limitations. For instance, these drivers were high on anti-social tendencies and

therefore potentially predisposed to ‘stretch the truth’. As such, some care needs to

be exercised when interpreting the results.

The final limitation of note is that only a finite number of situational and

person-related factors were able to be explored during Study Two. Knowing that a

large range of factors have the potential to influence any single aggressive driving

incident, this must be noted as a limitation.

7.7 Recommendations for Future Research

The research program identified a number of theoretical and applied issues

that require further research. Firstly, ongoing research into aggressive driving should

clearly define the phenomenon enabling more accurate measures of the behaviour.

Secondly, the full extent of aggressive driving in Australia needs to be examined in a

systematic fashion. In Queensland there are no systems currently in place to assist in

the identification of aberrant on-road behaviour as ‘aggressive driving’. Nor does the

current recording of charges under existing legislation (see Section 7.4.3) explicitly

identify an on-road incident as ‘aggressive driving’. Therefore, perhaps police and

insurance records could be modified to accommodate a simple coded entry that

identifies an incident as being consistent with aggressive driving behaviour.

Although such an assessment would be subjectively performed by key personnel,

training in how to identify and categorise aggressive driving incidents would enhance

the accuracy of the data input. Subsequently, more accurate rates of aggressive

driving would be obtained and the relevant insurance claims or charges could be

more closely examined for situational and person-related characteristics. It would

also be easier to determine the costs associated with aggressive driving behaviour.

Theoretically, the decision-making component of the GAM (Anderson &

Bushman, 2002) should be explored in greater detail within the general driving

population. For example, the results relating to the SPSI-R in Studies Two and

Three suggest that coping styles can have an impact on the decision-making process


underpinning aggressive driving responses. This information could, in turn, be

useful in the design of education packages and relevant cognitive behavioural

therapy programs for court identified offenders.

This research would also suggest that a more thorough exploration of driver

attitudes is necessary, extending existing research into driver vengeance (Hennessy

& Wiesenthal, 2001). Clearly, as suggested by this research driver attitudes and

stereotypes are shaped by life experiences. However, more information is required

on how such attitudes and stereotypes influence aggressive driving outcomes. Such

findings would enhance our understanding of the cognitions associated with

aggression on the roads, which could be incorporated into relevant programs.

The Study One findings also suggested that the presence of peer passengers,

exposure to music and vehicle appearance/modifications can impact on the

likelihood of aggressive driving behaviour. As such, it is recommended that further

research be conducted into the influence of these behaviours on aggressive driving

outcomes. These studies would benefit from the use of a driving simulator, where

the more controlled environment should minimise potential confounding variables.

Finally, more research is required into the contribution of biological and

neurological factors to the likelihood of aggressive driving as these factors were

outside of the scope of this research.

7.8 Concluding Remarks

This body of research indicates that aggressive driving is a complex

phenomenon. It appears to take many forms and involves a large range of possible

behaviours and outcomes. The likelihood of on-road aggression is also influenced by

a large number of person-related and situational factors. This program of research

has particularly highlighted the contribution of person-related factors to the incidence

and escalation of aggressive driving behaviours. Therefore, the research has

provided further support to the old adage in road safety, that ‘people drive as they

live’.


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Appendices

A Participant Information and Consent Package – Study One ...................................... 358

B Socio-Demographic questionnaire – Study One ........................................................ 360

C Focus Group Protocols – Study One ......................................................................... 363

D SPSS Output Socio-Demographic and Driving Exposure Data –

Study One .................................................................................................................. 367

E RACQ Sample Details ............................................................................................... 371

F Study Two Questionnaire .......................................................................................... 372

G Questionnaire Coverpage – RACQ participants ........................................................ 381

H Questionnaire Coverpage – QUT participants ........................................................... 382

I Internal Reliability Measures for Measures in the Study Two

Questionnaire ............................................................................................................. 385

J Analyses of Driving Behaviour Characteristics and Behavioural Intentions

of the Study Two Sample .......................................................................................... 393

K Differences in Trait Characteristics of the Study Two Sample ................................. 395

L PHA Driver results from the Study Two Sample ...................................................... 399

M Semi-structured Questionnaire – Study Three ........................................................... 405

N Interview Protocols – Study Three ............................................................................ 421

O Advertisement for Recruiting – Men’s Information and Support Association .......... 423

P Participant Consent Package – Study Three .............................................................. 424

Q Published M and SD associated with CPS and BIS 11 Measures .............................. 426

R Range of CPS Subscale Scores by Offender Type .................................................... 428

S Brief Descriptor of CPS Offender Type .................................................................... 438

T Individual Participant Scores on the AQ and SPSI-R and Significance

Levels – Study Three ................................................................................................. 439

U Individual Participant Scores on the BIS-11 and CPS and Significance

Levels – Study Three ................................................................................................. 440

V Individual Participant Case Studies – Study Three ................................................... 441


Appendix A: Participant Information and Consent Package – Study One

Where Does Young Driver Aggression Begin and End? The ‘on’ and ‘off-road’ Factors Associated with Aggressive Driving

Chief Investigator: Ms Sharon O'Brien 3864 4865 Email: [email protected] Supervisor: Mr Barry Watson 3864 4955 Email: [email protected] Co-Supervisors: Associate Professor R. Tay 3864 4806 Email: [email protected] Mr Graham Fraine 3864 4691 Email: [email protected] The information gathered via this focus group, will be used to complete the Chief Investigators, Masters of Applied Science (Research) thesis. The project is examining the emotions experienced by South-east Queensland drivers and the range of behavioural responses they engage in. In order to participate, you must hold a current driver’s licence. Participants are requested to participate to the best of their ability. The focus group should take approximately 1- 1 ½ hours to complete. Only aggregate data will be published and all information provided by you will be anonymous and treated as strictly confidential. To ensure this, the signed consent sheet shall remain separate from the completed demographic sheets. Participation in this research is voluntary and you are free to withdraw from the study at any time without comment or penalty. If the interview questions cause you any discomfort, you are free to contact the QUT Counselling and Health Services, by phoning 3864 4539, who have been informed about this study as a precaution and will provide counselling support, free of charge. Following the interview, if you have any queries I can be contacted on the number above or via email. If you have any concerns about the ethical conduct of this research please contact the Secretary, University Human Research Ethics Committee on 3864 2902. Copies of the findings of this study shall be made available if you are interested.

mailto:[email protected]



Your signature below will indicate that you:

• Have read the information provided above;

• Understand that you are able to withdraw from this study at any time without explanation;

• Understand that any information you provide will be treated as confidential; and

• Consent to participate in the research described above.

________________________ ______________________ ________ Participant’s Name Signature of Participant Date


Appendix B: Socio-Demographic Questionnaire – Study One

Group No. ……

Exploration of Aggressive Driving in South-east Queensland

Please take a moment to fill out this questionnaire.

First Name: ________________________________

Sex: Male Female

Age (in years): ________________________________

1. Please circle the number beside the length of time you have been driving.

1 year ……………………………….. 1

2 years ……………………………….. 2

3 years ……………………………….. 3

4 years ……………………………….. 4

5 years ……………………………….. 5

6 years ……………………………….. 6

7 years ……………………………….. 7

8 years ……………………………… 8


2. From the options below, please circle the number beside the approximate

distance you would drive per year.

Kilometres 0-5 000 ………………………………. 1

5 001 -10 000 ………………………………. 2

10 001 - 15 000 ……………………………….. 3

15 001 – 20 000 ……………………………….. 4

20 001 – 30 000 ……………………………….. 5

30 001 or more ……………………………….. 6

3. Below, please circle the number which best describes the types of roads you

generally drive on.

City road only …………………………………….. 1

Mainly city roads with some highway/country driving …………………………………….. 2 Both city and highway/ country driving …………………………………….. 3 Mainly highway/country driving …………………………………….. 4 Country roads only …………………………………….. 5 4. Approximately, how many times per week do you drive?

0-5 ………………………………… 1 6-10………………………………… 2 11-15……………………………… 3 16-20……………………………….. 4 More……………………………… 5


5. Are you required to drive at all for work purposes? Please circle your

response.

YES …………… or ……………… NO 6. Do you believe that aggressive driving is on the increase in Australia?

YES …………….. NO ………………UNSURE


Appendix C: Focus Group Protocols – Study One

Protocol for Focus Groups on Aggressive Driving

Hand out the demographic questionnaire/consent sheet as participants enter,

asking them to fill it out while settling in and while others are getting a cup of tea/coffee.

Also, hand out name tags.

Introduction

Good morning/evening and thank you for taking the time to be here. Let me

introduce myself. My name is Sharon O’Brien and I am a researcher from QUT.

Assisting me is Susan Hart also from QUT.

We’ll base today’s discussion around a series of general questions about driving.

There are no right or wrong answers to these questions and I expect that we may get

quite different points of view from the various people in the group. Please feel free to

share your views even if they differ from what others have said. You don’t need to

agree with others, but I’d like you to let others share their views.

Please speak up and if possible speak ‘one at a time’. My role as moderator will

be to encourage everyone to speak and to keep us on track during the discussion.

We’ll be on a first name basis today/tonight, but please be assured that your

names will not be used at any stage in the research and complete confidentiality is

assured. We shall be recording the session and be assured that your input today shall be

kept safe and confidential. The recordings shall be kept in a locked cabinet accessible

only to the researchers.

Our session will last about an hour and a half. While we won’t be taking a

formal break, please feel free to use the toilets (indicate location) and refill your drinks if

you are thirsty.

Today we’ll be talking about some of your experiences with aggressive driving

on the roads. The media would suggest that aggressive driving behaviour is increasing

in Australia. So we shall consider: What is aggressive driving? What causes it? and,


What do people think of it? Without a doubt the behaviour of some drivers can certainly

be annoying, to say the least.

Are there any questions? OK, lets get into it. With the first two questions we’ll

have a short open discussion then we shall go around the table and afterwards open it up

for discussion. If you could say your name the first time around that would be great.

Q1: What do you think are the main causes of aggressive driving?

Probe: Lack of courtesy, attitudes, intimidation, intention, stupidity, dangerousness, poor driving

Q2: What things make you particularly angry on the roads?

Q3: What do you think aggressive driving is?

Instructions – Q4&5 TO BE GATHERED FROM EACH PARTICIPANT

Q4: a) Can you think of an instance where you may have acted angrily on the road or responded angrily to someone?

b) How were you feeling immediately before the incident?

c) Specifically, what was it that prompted your feelings/behaviour?

d) Did you aim this behaviour at another driver?

e) Did you do so intentionally?

f) What feelings did you experience in this situation?

g) Can you recall having any particular ‘thoughts’ while it was happening?


Q5: a) How did the other driver(s) react ?

b) What went through your mind at this point?

c) Would you consider that your response could be interpreted as aggressive?

• Probe – justification

d) Immediately after the incident (say for the next 15 minutes) how did you

feel?

e) Some time after the incident (say 1 hour later), did you feel any differently

about the incident?

Q6: Following an aggressive driving incident, have any of you felt

upset/frustrated/angry after you finished driving?

Probe: Do you think it affected your off-road behaviour?

How did this affect your off-road behaviour?

Q7: Can you think of instances where you got into your vehicle feeling upset/tense/under pressure?

Probe: Do you think this has affected your on-road behaviour?

How did this affect your behaviour?

Q8 What types of ‘off-road’ things do you think may effect ‘on-road’

behaviour in general?

• This question is not necessarily about personal experience

Finish

Unfortunately we are running out of time, but today/tonight’s discussion has

been extremely valuable for us. As we come to a close I again want to remind you that


all the comments you have made will remain entirely anonymous, and ask that you also

keep the comments of other group members to yourself so that each person can remain

anonymous.

Are there any questions I can answer for you?

Once again thank you, we very much appreciate your involvement.


Appendix D: SPSS Output Socio-Demographic and Driving Exposure Data - Study One

GENDER Statistics GENDER

N Valid 47 Missing 0

Mode 2 Range 1

GENDER

Frequency Percent Valid Percent Cumulative

Percent Valid male 22 46.8 46.8 46.8

female 25 53.2 53.2 100.0 Total 47 100.0 100.0

AGE Statistics AGE


Mode 18 Range 7

AGE


Percent Valid 18 12 25.5 25.5 25.5

19 9 19.1 19.1 44.7 20 2 4.3 4.3 48.9 21 9 19.1 19.1 68.1 22 4 8.5 8.5 76.6 23 5 10.6 10.6 87.2 24 1 2.1 2.1 89.4 25 5 10.6 10.6 100.0 Total 47 100.0 100.0


NUMBER OF YEARS DRIVING Statistics TIMEDRIV


Mode 1 Range 7

TIMEDRIV


Percent Valid 1 year 15 31.9 31.9 31.9

2 years 8 17.0 17.0 48.9 3 years 5 10.6 10.6 59.6 4 years 6 12.8 12.8 72.3 5 years 6 12.8 12.8 85.1 6 years 3 6.4 6.4 91.5 7 years 2 4.3 4.3 95.7 8 years 2 4.3 4.3 100.0 Total 47 100.0 100.0

APPROXIMATE DISTANCE TRAVELLED PER YEAR Statistics DISTPYR


Mode 3 Range 5

DISTPYR


Percent Valid 0-5 000 8 17.0 17.0 17.0 5 001-10 000 8 17.0 17.0 34.0 10 001-15 000 14 29.8 29.8 63.8 15 001-20 000 9 19.1 19.1 83.0 20 001-30 000 4 8.5 8.5 91.5 30 001 or more 4 8.5 8.5 100.0 Total 47 100.0 100.0


TYPE OF ROAD Statistics TYPEROAD


Mode 2 Range 3

TYPEROAD


Percent Valid cityroadonly 1 2.1 2.1 2.1

citysomehwyorcntryroad 30 63.8 63.8 66.0

bothcity&hway/cntry 14 29.8 29.8 95.7

mainlyhwaycountry 2 4.3 4.3 100.0

Total 47 100.0 100.0

NUMBER OF TIMES DRIVE PER WEEK Statistics NOTIMPW


Mode 3 Range 4

NOTIMPW


Percent Valid 0-5 3 6.4 6.4 6.4

6-10 12 25.5 25.5 31.9 11-15 14 29.8 29.8 61.7 16-20 6 12.8 12.8 74.5 more 12 25.5 25.5 100.0 Total 47 100.0 100.0


DRIVE FOR WORK Statistics WORK


Mode 2 Range 1

WORK


Percent Valid yes 21 44.7 44.7 44.7

no 26 55.3 55.3 100.0 Total 47 100.0 100.0

PERCIEVED INCREASE Statistics PERINCRE


Mode 1 Range 2

PERINCRE


Percent Valid yes 35 74.5 74.5 74.5

unsure 12 25.5 25.5 100.0 Total 47 100.0 100.0

DESCRIPTIVES Descriptive Statistics

N Range Minimum Maximum Mean GENDER 47 1 1 2 1.53 AGE 47 7 18 25 20.60 TIMEDRIV 47 7 1 8 3.15 DISTPYR 47 5 1 6 3.11 TYPEROAD 47 3 1 4 2.36 NOTIMPW 47 4 1 5 3.26 WORK 47 1 1 2 1.55 PERINCRE 47 2 1 3 1.51 Valid N (listwise) 47


Appendix E: RACQ Sample Details

RACQ Region Under 25 yrs 25-44 yrs 45-64 yrs 65 or older Total

Brisbane, Ipswich & surrounding

areas

Gold Coast

S.W. Queensland

Central Queensland

Wide Bay

North Queensland

Far North Queensland

Male Female

400 400

100 100

95 95

90 90

125 125

100 100

90 90

Male Female 200 200 50 50 45 45 40 40 75 75 50 50 40 40

Male Female

200 200

50 50

45 45

40 40

75 75

50 50

40 40

Male Female

200 200

50 50

45 45

40 40

75 75

50 50

40 40

TOTAL

2,000

500

460

420

700

500

420

5,000


Appendix F: Driving Questionnaire – Study Two

The first of our questions are about you and your driving. Please circle one number to show your answer for each question. Remember – all the information you provide is completely confidential and your anonymity is assured. If you decide you don’t want to answer a question, that is OK. Please just go on to the next question. 1. What type of vehicle do you drive most often? Please circle one number only.

Small car…………..………………………………… Medium car………………….……………………… Large car………….………………………………… Small/Medium 4WD……………………………….. Large 4WD………………………………………….. Utility/small truck…………………………………… Large Truck…………………………………………. Motorcycle…………………………………………... Van/people mover/mini-bus………………………. Other (please specify _____________________)

1 2 3 4 5 6 7 8 9 10

2. Where do you most often drive your vehicle? Please circle one number only.

City/Town roads light traffic…………………….…. City/Town roads medium traffic…………….…….. City/Town roads heavy traffic…………………….. Highways/open roads light traffic…………………. Highways/open roads medium traffic……………. Highways/open roads heavy traffic……………….

1 2 3 4 5 6

3. How many hours do you usually drive a vehicle per week? Please circle one number only.

0-5…………………………….. 1 6-10…………………………… 2 11-15…………………………… 3 16-20……….…………………. 4 More than 20……………………5

4. During the last 3 years, how many crashes have you been involved in (irrespective of whether you were considered at fault or not)? ______________________(write in the number)

A “crash” involves damage occurring to a vehicle/vehicles

or property, with or without injuries being sustained,

irrespective of whether it was reported to the police.


5. Have you been booked for any traffic offences (not parking tickets) during the last 3 years?

(Circle one number for each type of offence)

Speeding 0 1 2 3+ Drink driving 0 1 2 3+ Driving without a valid Licence 0 1 2 3+ Other 0 1 2 3+

6. Please circle the appropriate response to the following questions.

How likely are you to drive 10kms or more over the speed limit on an urban road?……………………..

How likely are you to drive 10kms or more over the speed limit on a rural road or highway?.………..

How likely are you to drive when you think you might be over the legal alcohol limit?……….……………….

How likely are you to drive under the influence of recreational drugs?……………………………………

Not at all Extremely Likely Likely

1 2 3 4 5

1 2 3 4 5

1 2 3 4 5

1 2 3 4 5

7. Are you: Male .................................1

Female ............................2

8. What is your age? 17-18… .................... .1 19-20 ..................... ....2 21-24 ........................ .3 25-29 ......................... 4 30-39 ......................... 5 40-49 ......................... 6 50-59 ......................... 7 60 or more ................. 8

9. What is the postcode where you live?

10. What is your highest level of formal education

you have completed?

Primary…………………………………………………...1 Junior (Grade 10)……..…..…………………………….2 Senior (Grade 12)………….……………………………3 TAFE/Tech College/Apprenticeship……………..…. .. 4 CAE/University .……………………………….………..5 Other (Please specify) ________________________6

11. On each of the scales below, could you please circle the appropriate number that best indicates how you are feeling right now?


Very Happy

1

2

3

4

5

Very Unhappy

Very Calm

1 2 3 4 5 Very Agitated

Not stressed at all

1 2 3 4 5 Very Stressed

12. Please circle the number which best indicates how characteristic the following statements are about you, from‘1’ Extremely Uncharacteristic to ‘5’ Extremely characteristic.

Extremely Extremely Uncharacteristic Characteristic

If somebody hits me, I hit back 1 2 3 4 5

I tell my friends openly when I disagree with them 1 2 3 4 5

When frustrated, I let my irritation show 1 2 3 4 5

There are people who pushed me so far that we came to blows 1 2 3 4 5

I am sometimes eaten up with jealousy 1 2 3 4 5

When people annoy me, I may tell them what I think of them 1 2 3 4 5

I am an even tempered person 1 2 3 4 5

At times I feel I have gotten a raw deal out of life 1 2 3 4 5

Once in a while I can’t control the urge to strike another person 1 2 3 4 5

I often find myself disagreeing with people 1 2 3 4 5

I flare up quickly but get over it quickly 1 2 3 4 5

Some of my friends think I’m a hothead 1 2 3 4 5

Other people always seem to get the breaks 1 2 3 4 5

Given enough provocation, I may hit another person 1 2 3 4 5

I can’t help getting into arguments when people disagree with me 1 2 3 4 5

I wonder why sometimes I feel so bitter about things 1 2 3 4 5

If I have to resort to violence to protect my rights, I will 1 2 3 4 5

I have trouble controlling my temper 1 2 3 4 5

I can think of no good reason for ever hitting a person 1 2 3 4 5

I know that “friends” talk about me behind my back 1 2 3 4 5

My friends say that I’m somewhat argumentative 1 2 3 4 5

I sometimes feel like a powder keg ready to explode 1 2 3 4 5

I am suspicious of overly friendly strangers 1 2 3 4 5


I have threatened people I know 1 2 3 4 5

Sometimes I fly off the handle for no good reason 1 2 3 4 5

I sometimes feel that people are laughing at me behind my back 1 2 3 4 5

I have become so mad that I have broken things 1 2 3 4 5

I get into fights a little more than the average person 1 2 3 4 5

When people are especially nice, I wonder what they want 1 2 3 4 5 13. The following questions look at how you generally think and feel about problems and how you might solve them. In this questionnaire, a problem is something important in your life that bothers you a lot, but you don’t immediately know how to make it better or stop it from bothering you so much. The problem could be something about yourself (such as your thoughts, feelings, behaviour, health, or appearance), your relationships with other people (such as your family, friends, teachers or boss), or your environment and the things you own (such as your house, car, property or money). Please read each statement carefully and choose one of the numbers below that best shows how much the statement is true of you. See yourself as you usually think, act and feel when you are faced with important problems in your life these days. Not at all

True of Me Slightly True of

Me

Moderately True of Me

Very True of

Me

Extremely True of Me

I feel threatened and afraid when I have an important problem to solve.

1

2

3

4

5

When making decisions, I do not evaluate all my options carefully enough.

1

2

3

4

5

I feel nervous and unsure of myself when I have an important decision to make.

1

2

3

4

5

When my first efforts to solve a problem fail, I get very frustrated.

1

2

3

4

5

When I am faced with a difficult problem, I doubt that I will be able to solve it on my own no matter how hard I try

1

2

3

4

5

Difficult problems make me very upset. 1

2

3

4

5

When I have a decision to make I try to predict the positive and negative consequences of each option.

1

2

3

4

5

When I am trying to solve a problem, I go with the first good idea that comes to mind.

1

2

3

4

5

When I have a problem to solve, one of the first things I do is get as many facts about the problem as possible.

1

2

3

4

5

Before I try to solve a problem, I set a specific goal so that I know exactly what I want to accomplish.

1

2

3

4

5


When I have a decision to make, I do not take the time to consider the pros and cons of each option.

1

2

3

4

5

After carrying out a solution to a problem, I try to evaluate as carefully as possible how much the situation has changed for the better.

1

2

3

4

5

When I am trying to solve a problem, I think of as many options as possible until I cannot come up with any more ideas.

1

2

3

4

5

When making decisions, I go with my “gut feeling” without thinking too much about the consequences of each option.

1

2

3

4

5

I am too impulsive when it comes to making decisions. 1 2 3 4 5


The remainder of this questionnaire will present you with two driving scenarios. Following each scenario you will be asked to rate how you would feel in the situation and how likely you would be to respond in different ways. Please circle the number which best describes your level of agreement with the questions provided. Please give your most immediate response.

Scenario One You are driving down a two lane road (one lane each way) travelling at the speed limit and you notice that the

car behind you is travelling very close to your vehicle. Instead of waiting for an opportunity to overtake you, the driver proceeds to flash his/her lights and beep his/her horn.

1. Please circle the number on the scale below which best rates how you may feel in this situation. Not at All Very Much

a) Angry…………………………………………………….. 1 2 3 4 5

b) Threatened ..……………………………………………. 1 2 3 4 5

c) Annoyed . ………………………………………………. 1 2 3 4 5

d) Agitated…..……………………………………………… 1 2 3 4 5

2. How likely are you to have the following immediate thoughts about the other driver? Extremely

Unlikely Extremely

Likely

a) What an idiot! ………………………………………….. 1 2 3 4 5

b) How did that fool get his licence! ……………………. 1 2 3 4 5

c) That idiot shouldn’t be allowed on the road!………… 1 2 3 4 5

3. Thinking about the scenario again, please circle the number beside each of the statements below, that would best indicate the likelihood of you responding to the situation in this way. The scale is as follows: Extremely

Unlikely Extremely

Likely 1. Swear or mutter to yourself or others in your car 1 2 3 4 5 2. Give a blast of your horn. 1 2 3 4 5 3. Carry on driving normally. 1 2 3 4 5 4. Gesture at the other driver. 1 2 3 4 5 5. Swear at and/or verbally abuse the other driver. 1 2 3 4 5 6. After they have overtaken you, drive close to/follow the Other vehicle. 1 2 3 4 5

7. Ignore the driver/incident as if nothing has happened. 1 2 3 4 5 8. Stop the vehicle and get out of your vehicle, ready to argue. 1 2 3 4 5 9. Stop the vehicle and get out prepared to engage physically with the other driver. 1 2 3 4 5 10. Shout or scream out loud but not at the offending driver. 1 2 3 4 5


11. Use your vehicle to physically damage the other driver’s vehicle.

1 2 3 4 5

4. After this incident, how likely are you to have the following reactions? Not at all Extremely

likely likely

Forget about it almost immediately. 1 2 3 4 5

Feel better once you have responded in the manner you have indicated above. 1 2 3 4 5

Feel upset or irritable until later in the journey. 1 2 3 4 5

Forget about it once you have left the car. 1 2 3 4 5

Forget about it once you start on another task. 1 2 3 4 5

Feel upset or irritable for the rest of the day. 1 2 3 4 5

Only feel better after having talked with a friend or relative upon arrival at your destination. 1 2 3 4 5

5. How likely is it that this incident would affect you……………….. Not at all Extremely

likely likely

During the rest of your trip. 1 2 3 4 5

Doing other tasks during the day. 1 2 3 4 5

In your dealings with others. 1 2 3 4 5

Scenario Two You have just had an argument with someone close to you, prior to getting in the car. You then approach an

intersection and the light changes to ‘red’. You come to a stop behind another car. The light seems to take a long time to change back to ‘green’. When the light finally changes the driver in front does not move off, preventing you

from moving forward. 1. Please circle the number on the scale below which best rates how you may feel in this situation. Not at All Very Much

a) Angry…………………………………………………….. 1 2 3 4 5

b) Threatened ..……………………………………………. 1 2 3 4 5

c) Annoyed . ………………………………………………. 1 2 3 4 5

d) Agitated…..……………………………………………… 1 2 3 4 5


2. How likely are you to have the following immediate thoughts about the other driver? Extremely

Unlikely Extremely Likely

a) What an idiot! ………………………………..……….. 1 2 3 4 5

b) How did that fool get his licence! ……………………. 1 2 3 4 5

c) That idiot shouldn’t be allowed on the road!………… 1 2 3 4 5

3. Thinking about the scenario again, please circle the number beside each of the statements below, that would best indicate the likelihood of you responding to the situation in this way. The scale is as follows: Extremely

Unlikely Extremely Likely

1. Swear or mutter to yourself or others in your car 1 2 3 4 5 Give a blast of your horn and/or flash lights. 1 2 3 4 5

3. Carry on driving normally. 1 2 3 4 5 4. Gesture at the other driver. 1 2 3 4 5 5. Swear at and/or verbally abuse the other driver. 1 2 3 4 5 6. Drive close to/follow the other vehicle. 1 2 3 4 5 7. Ignore the driver/incident as if nothing has happened. 1 2 3 4 5

8. Stop the vehicle and get out of your vehicle, ready to argue. 1 2 3 4 5

9. Stop the vehicle and get out prepared to engage physically

with the other driver. 1 2 3 4 5

10. Shout or scream out loud but not at the offending driver. 1 2 3 4 5

11. Use your vehicle to physically damage the other driver’s

vehicle. 1 2 3 4 5

4. After this incident, how likely are you to have the following reactions? Not at all Extremely

likely likely Forget about it almost immediately. 1 2 3 4 5 Feel better once you have responded in the manner you have indicated above. 1 2 3 4 5

Feel upset or irritable until later in the journey. 1 2 3 4 5 Forget about it once you have left the car. 1 2 3 4 5 Forget about it once you start on another task. 1 2 3 4 5 Feel upset or irritable for the rest of the day. 1 2 3 4 5 Only feel better after having talked with a friend or relative upon arrival at your destination. 1 2 3 4 5


5. How likely is it that this incident would affect you………………. Not at all Extremely

likely likely

During the rest of your trip. 1 2 3 4 5

While doing other tasks during the day. 1 2 3 4 5

In your dealings with others. 1 2 3 4 5


Appendix G: Questionnaire Information and Consent Sheet Study Two – RACQ Participants

Driving Questionnaire

Dear Sir/Madam, This research will explore the emotions experienced by Queensland drivers and the range of behaviours they engage in as a result of anger-provoking incidents. We would truly appreciate your assistance in improving our understanding of general driver behaviour by completing the following survey. It should take approximately 20 minutes to complete and a reply paid envelope has been provided for the return of the questionnaire to CARRS-Q. Participants are requested to answer the following questions to the best of their ability. Remember, your participation is strictly voluntary and your confidentiality is assured. However, if you choose to complete the survey, you will be automatically entered into the competition for a free, 1 year, RACQ membership. If the interview questions cause you any discomfort, you are free to contact the QUT, Family Therapy and Counselling Clinic, by phoning (07) 3864 4578, who have been informed about this study as a precaution and will provide counselling support, free of charge. If you have any concerns about the ethical conduct of this research please contact the Secretary, University Human Research Ethics Committee on (07) 3864 2902. Alternatively, if you have any questions about the research please feel free to telephone me on (07) 3864 4685. Thanks again for your co-operation.

Sharon O’Brien


Appendix H: Questionnaire Information and Consent Sheet Study Two – QUT Participants

Where Does Driver Aggression Begin and End? The ‘on’ and ‘off-road’ Factors Associated with Aggressive Driving

Chief Investigator: Ms Sharon O'Brien 3864 4865 Supervisor: Mr Barry Watson 3864 4955 Email: [email protected] Co-Supervisors: Associate Professor R. Tay 3864 4806 Email: [email protected] Mr Graham Fraine 3864 4691 Email: [email protected] The information gathered via this semi-structured interview, will be used to complete the Chief Investigators, Masters of Applied Science (Research) thesis. The project is examining the emotions experienced by Australian drivers and the range of behavioural responses they engage in. In order to participate, you must hold a current driver’s licence. Participants are requested to answer all questions to the best of their ability. The interview should take approximately 20 minutes. Only aggregate data will be published and all information provided by you will be anonymous and treated as strictly confidential. To ensure this, the signed consent sheet shall remain separate from the completed interview sheets. Participation in this research is voluntary and you re free to withdraw from the study at any time without comment or penalty. If the questions cause you any discomfort, you are free to contact the QUT Counselling and Health Services, by phoning 3864 4539, who have been informed about this study as a precaution and will provide counselling support, free of charge. Following the interview, if you have any queries I can be contacted on the number above or via email. If you have any concerns about the ethical conduct of this research please contact the Secretary, University Human Research Ethics Committee on 3864 2902. Copies of the findings of this study shall be made available if you are interested.





• Have read the information provided above;

• Understand that you are able to withdraw from this study at any time without explanation;

• Understand that any information you provide will be treated as confidential; and

• Consent to participate in the research described above.

________________________ ______________________ ________ Participant’s Name Signature of Participant Date I wish to receive feedback on the results of this study when it is completed Circle One: YES NO If you would like to receive feedback, please provide a phone number or e-mail address where you would like us to contact you with the results. (Phone/e-mail)________________________________________________


Appendix I: Internal Reliability Measures for Measures used in the Study Two Questionnaire

Reliability - Aggression Questionnaire

Reliability Statistics

.900 .913 29

Cronbach'sAlpha

Cronbach'sAlpha Based

onStandardized

Items N of Items

Item-Total Statistics

54.8117 224.127 .468 .426 .897 53.8058 228.501 .362 .355 .899 54.0660 223.148 .528 .419 .896 55.3130 224.182 .532 .419 .896 55.1173 224.354 .533 .405 .896 54.5225 223.934 .506 .451 .896 53.6799 240.969 -.004 .143 .908 54.8388 224.392 .491 .449 .897 55.7517 233.744 .473 .354 .898 54.7747 226.024 .528 .379 .896 54.6521 224.099 .484 .350 .897 55.4970 226.367 .583 .458 .895 55.0856 225.366 .515 .488 .896 55.2538 224.370 .502 .558 .896 55.2150 224.453 .607 .470 .895 55.2863 224.743 .581 .499 .895 55.2099 225.372 .484 .504 .897 55.4857 226.582 .596 .524 .895 53.9854 240.202 -.003 .172 .910 55.0671 224.885 .503 .407 .896 55.2791 224.443 .595 .486 .895 55.4682 224.630 .615 .499 .895 54.4205 224.677 .426 .418 .898 55.6845 229.452 .585 .510 .896 55.3807 226.582 .537 .481 .896 55.2956 225.011 .561 .544 .895 55.3601 224.267 .559 .395 .895 55.8000 233.953 .509 .474 .898 54.8063 223.897 .512 .479 .896

SMEAN(AQ1) SMEAN(AQ2) SMEAN(AQ3) SMEAN(AQ4) SMEAN(AQ5) SMEAN(AQ6) SMEAN(AQ7) SMEAN(AQ8) SMEAN(AQ9) SMEAN(AQ10) SMEAN(AQ11) SMEAN(AQ12) SMEAN(AQ13) SMEAN(AQ14) SMEAN(AQ15) SMEAN(AQ16) SMEAN(AQ17) SMEAN(AQ18) SMEAN(AQ19) SMEAN(AQ20) SMEAN(AQ21) SMEAN(AQ22) SMEAN(AQ23) SMEAN(AQ24) SMEAN(AQ25) SMEAN(AQ26) SMEAN(AQ27) SMEAN(AQ28) SMEAN(AQ29)

Scale Mean if Item Deleted

Scale Variance if Item Deleted

Corrected Item-Total Correlation

Squared Multiple

Correlation

Cronbach's Alpha if Item

Deleted


Reliability - Negative Problem Orientation Subscale (SPSI-R)

Reliability - Impulsive/Careless Style (SPSI-R Subscale)


.843 .844 5

Cronbach'sAlpha


onStandardized

Items N of Items


7.9480 9.789 .664 .473 .8087.6377 8.962 .683 .496 .8027.7140 9.458 .649 .424 .8118.1726 9.992 .617 .394 .8207.9555 9.442 .637 .414 .815

SMEAN(SPS1)SMEAN(SPS3)SMEAN(SPS4)SMEAN(SPS5)SMEAN(SPS6)

Scale Mean ifItem Deleted

ScaleVariance if

Item Deleted

CorrectedItem-TotalCorrelation

SquaredMultiple

Correlation

Cronbach'sAlpha if Item

Deleted


.765 .766 5

Cronbach'sAlpha


onStandardized

Items N of Items


7.6803 8.996 .483 .247 .7407.5354 8.477 .486 .242 .7417.8338 8.373 .543 .309 .7207.4262 8.150 .560 .339 .7147.8130 8.253 .606 .377 .698



ScaleVariance if

Item Deleted


SquaredMultiple

Correlation


Deleted


Reliability - Rational Problem Solving (SPSI-R Subscale)

Reliability - Negative Emotions (Scenario One)


.821 .823 5

Cronbach'sAlpha


onStandardized

Items N of Items


13.1582 13.250 .478 .244 .82712.9887 12.002 .707 .509 .75813.3158 12.800 .616 .417 .78513.4569 12.637 .647 .447 .77613.4239 12.386 .634 .435 .779



ScaleVariance if

Item Deleted


SquaredMultiple

Correlation


Deleted


.786 .787 3

Cronbach'sAlpha


onStandardized

Items N of Items

Item-Tota l Sta tistics

6.2116 4.591 .685 .472 .6435.3914 5.192 .607 .389 .7306.2167 4.801 .589 .357 .752

SMEAN(S1ANGER)SMEAN(S1ANNOY)SMEAN(S1AGITAT)


ScaleVariance if

Item Deleted

Correc tedItem-TotalCorrelation

SquaredMultiple

Correlation


Deleted


Reliability - Negative Emotions (Scenario Two)

Reliability - Negative Attributions (Scenario One)


.848 .848 3

Cronbach'sAlpha


onStandardized

Items N of Items


5.2565 5.148 .732 .536 .7724.5089 5.294 .703 .495 .8005.2567 5.134 .712 .509 .791

SMEAN(S2ANGER)SMEAN(S2ANNOY)SMEAN(S2AGITAT)


ScaleVariance if

Item Deleted


SquaredMultiple

Correlation


Deleted


.812 .808 3

Cronbach'sAlpha


onStandardized

Items N of Items


5.9816 7.368 .508 .258 .8837.1661 4.982 .752 .636 .6446.9891 4.955 .761 .641 .633

SMEAN(S1COGA)SMEAN(S1COGB)SMEAN(S1COGC)


ScaleVariance if

Item Deleted


SquaredMultiple

Correlation


Deleted


Reliability - Negative Attributions (Scenario Two)

Reliability - Behavioural Response Items (Scenario One)


.843 .855 3

Cronbach'sAlpha


onStandardized

Items N of Items


3.6600 5.179 .595 .354 .9154.5619 5.470 .782 .725 .7174.6007 5.529 .782 .724 .719

SMEAN(S2COGA)SMEAN(S2COGB)SMEAN(S2COGC)


ScaleVariance if

Item Deleted


SquaredMultiple

Correlation


Deleted


.769 .806 9

Cronbach'sAlpha


onStandardized

Items N of Items


11.3695 19.002 .347 .160 .77813.4445 19.760 .503 .277 .74012.9513 16.283 .642 .541 .71313.2969 16.924 .700 .586 .70113.4789 19.981 .445 .219 .74913.8755 22.493 .496 .644 .75513.9103 23.082 .410 .712 .76313.5950 20.165 .482 .249 .74313.9395 23.610 .310 .486 .770

SMEAN(S1BEH1)SMEAN(S1BEH2)SMEAN(S1BEH4)SMEAN(S1BEH5)SMEAN(S1BEH6)SMEAN(S1BEH8)SMEAN(S1BEH9)SMEAN(S1BEH10)SMEAN(S1BEH11)


ScaleVariance if

Item Deleted


SquaredMultiple

Correlation


Deleted


Reliability – Instrumental Behavioural Response Items (Scenario One)

Reliability – Hostile Behavioural Response Items (Scenario One)


.764 6

Cronbach'sAlpha N of Items


8.1468 14.633 .378 .77210.2218 15.602 .515 .729

9.7286 12.461 .656 .68410.0742 13.274 .684 .67910.2562 16.115 .410 .75210.3723 16.254 .450 .744

SMEAN(S1BEH1)SMEAN(S1BEH2)SMEAN(S1BEH4)SMEAN(S1BEH5)SMEAN(S1BEH6)SMEAN(S1BEH10)


ScaleVariance if

Item Deleted



Deleted


.853 3



2.1156 .463 .718 .8132.1503 .482 .842 .6792.1795 .621 .641 .870

SMEAN(S1BEH8)SMEAN(S1BEH9)SMEAN(S1BEH11)


ScaleVariance if

Item Deleted



Deleted


Reliability - Behavioural Response Items (Scenario Two)

Reliability – Instrumental Behavioural Response Items (Scenario Two)


.737 .795 9

Cronbach'sAlpha


onStandardized

Items N of Items


11.4031 15.779 .405 .214 .73011.7315 14.950 .445 .241 .72412.7739 15.990 .613 .567 .67312.9862 16.788 .675 .625 .66913.0782 18.575 .499 .335 .70313.3177 21.051 .325 .470 .73213.3350 21.105 .370 .734 .73113.0715 18.434 .463 .241 .70613.3458 21.448 .275 .616 .737

SMEAN(S2BEH1)SMEAN(S2BEH2)SMEAN(S2BEH4)SMEAN(S2BEH5)SMEAN(S2BEH6)SMEAN(S2BEH8)SMEAN(S2BEH9)SMEAN(S2BEH10)SMEAN(S2BEH11)


ScaleVariance if

Item Deleted


SquaredMultiple

Correlation


Deleted


.744 6



8.2605 12.894 .438 .7318.5889 12.169 .473 .7249.6313 13.406 .618 .6709.8436 14.344 .647 .6759.9356 16.136 .443 .7239.9289 15.820 .442 .721

SMEAN(S2BEH1)SMEAN(S2BEH2)SMEAN(S2BEH4)SMEAN(S2BEH5)SMEAN(S2BEH6)SMEAN(S2BEH10)


ScaleVariance if

Item Deleted



Deleted


Reliability – Hostile Behavioural Response Items (Scenario Two)

Reliability - Post Event Influence (Scenario One)


.826 3



2.0800 .370 .590 .8722.0972 .352 .839 .6032.1080 .427 .652 .793

SMEAN(S2BEH8)SMEAN(S2BEH9)SMEAN(S2BEH11)


ScaleVariance if

Item Deleted



Deleted


.817 .844 3

Cronbach'sAlpha


onStandardized

Items N of Items


2.7157 1.935 .609 .414 .8793.1481 2.425 .803 .699 .6363.2130 2.749 .682 .617 .755

SMEAN(S1PBEH1)SMEAN(S1PBEH2)SMEAN(S1PBEH3)


ScaleVariance if

Item Deleted


SquaredMultiple

Correlation


Deleted


Reliability - Post Event Influence (Scenario Two)


.847 .865 3

Cronbach'sAlpha


onStandardized

Items N of Items


2.3650 1.175 .631 .405 .9102.5702 1.393 .805 .727 .7212.5680 1.389 .764 .703 .750

SMEAN(S2PBEH1)SMEAN(S2PBEH2)SMEAN(S2PBEH3)


ScaleVariance if

Item Deleted


SquaredMultiple

Correlation


Deleted


Appendix J Analyses of the Driving Behaviour Characteristics and Behavioural Intentions of the

Study Two Sample

Some of the variables were recoded to meet sufficient cell sizes (i.e. n > 5) to

enable Chi- Square (χ2) analysis (Tabachnick & Fidell, 1996). The effected variables

were self-reported speeding fines incurred in the past three years and crash involvement

in the past three years. Also, due to the overrepresentation of young drivers in on-road

aggression, special attention is given to those drivers aged 17–24 years of age in the

sample. In order to test for any significant age and gender differences the age variable

was reduced to ‘1’ - 17–24 year olds and ‘0’ – 25 years and older.

Table J1

Chi-square analysis of number of speeding fines in the previous three years by age

Number of Speeding Fines in the Last

Three Years (n = 896)

Drivers 17-24 years

of age

Drivers 25 years and

over

Significance Level

None

223 34.5%

423 65.5%

χ2 (df2)= 4.456, p > .05

One

59 35.5%

107 64.5% Two or More Fines

39 46.4%

45 53.6%

Table J2

Chi-square analysis of number of speeding fines in the previous three years by gender

Number of Speeding Fines in the Last

Three Years (n = 896)

Female

Male

Significance Level

None

415 64.2%

231 35.8%

χ2 (df2)= 10.803, p < .05, øc=.11

One

96 57.8%

70 42.2% Two or More Fines

39 46.4%

45 53.6%


Table J3

Self-reported number of participants fined for DUI of alcohol, unlicensed driving and

other offences in the past three years

Frequency Driving Under the Influence Alcohol

Unlicensed Driving Other Offences

1

7

3

42

2 0 0 5

3 or more 1 1 4

TOTAL 8 4 51

Table J4

Chi-square analysis of age by number of self-reported crashes in the previous three

years

Number of Self-reported Crashes in

the Last Three Years (n = 921)*

17-24 Year Old Drivers

Older Drivers

Significance Level

None

220 31.9%

470 68.1%

χ2 (df1) = 19.2, p < .001, ø = .15

One or More

111 48.1%

120 51.9%

*The self-reported ‘number of crashes in the previous three years’ was recoded into a dichotomous variable, ‘no crashes’ versus ‘one or more crashes’ so that the cell size requirement of > 5 was met (Tabachnick & Fidell, 1996).

Table J5 Chi-square analysis of number of self-reported crashes in the previous three

years by gender

Number of Self-reported crashes in

the Last Three Years (n = 921)

Female

Male

Significance Level

None

368 60.4%

298 39.6%

χ2 (df1)= .157, p > .05

One or More Fines 374 61.9% 287 38.1%


Appendix K

Differences in Trait Characteristics of the Study Two Sample Table K1 Results of gender by age-group ANOVAs on AQ and SPSI-R subscales with post-hoc tests

A conservative probability level of p < .006 was adopted to determine the significance of the ANOVAs, the multiple tests performed (i.e. Bonferroni adjustment .05 ÷ 4 = p < .0125). Post hoc comparisons were conducted using Dunnet’s C at p < .05.

Total Trait Aggression

A 2x4 ANOVA for gender and age-group by total trait aggression scores was

significant [F (7,918) = 44.895, p < .001]. No significant interaction was found [F

(7,918) = 1.56, p = .197]. However, simple main effects (SME’s) were found for both

gender [F (1,918) = 24.25, p < .001, η2 = .03] and age-group [F (3,918) = 96.32, p <

.001, η2 = .24]. Male participants (M = 48.7) scored significantly higher on the total AQ

than females (M = 43.8). However, the effect size for the significant age-group SME (η2

= .24) was considerably greater than for gender (η2 = .03). Post hoc comparisons using

Dunnett’s C showed participants aged 17–24 years scored significantly higher levels of

overall trait aggression than any other age group, (p < .05). Older participants, 60 years

Variable by Scenario

M

17-24y

Male

(n = 106)

M

17-24y

Female

(n = 226)

M

25-39y

Male

(n = 41)

M

25-39y

Female

(n = 116)

M

40-59y

Male

(n = 105)

M

40-59y

Female

(n = 128)

M

60+ y

Male

(n = 110)

M

60+ y

Female

(n = 94)

Overall ANOVA

Sig. Level

Aggression Questionnaire (AQ) Total AQ

58.38

53.46

49.80

47.75

49.22

41.10

37.22

33.07

p < .001

Physical Aggression 14.84 11.58 11.93 10.02 11.83 8.72 8.20 6.40 p < .001

Verbal Aggression

13.27 12.48 11.95 10.98 11.59 10.01 9.91 8.49 p < .001

Angry Aggression

11.31 10.96 8.98 10.85 9.67 8.78 6.99 6.20 p < .001

Hostile Aggression

18.96 18.43 16.95 15.89 16.13 13.59 12.12 11.96 p < .001

Social Problem Solving (SPSI-R)

Negative Problem Solving (NPO)

5.21

5.49

5.08

5.17

5.14

5.14

4.92

5.14

p < .001

Impulsive/Careless Style (ICS)

5.39

5.27

5.22

5.18

5.05

5.08

4.97

5.02

p < .001

Rational Problem Solving(RPS)

3.19

3.25

3.39

3.41

3.40

3.39

3.43

3.16

p < .105


plus, reported significantly less trait aggression than other age-groups, (p < .05). Drivers

aged 25–39 years and 40–59 years reported similar total trait aggression scores as each

other, (p > .05).

Physical Aggression Subscale

The overall ANOVA to evaluate the effects of age-group by gender on self-

reported levels of trait physical aggression was significant, [F (7,918) = 34.442, p <

.001]. Analysis revealed a significant simple main effect (SME) for gender, males (M =

11.7) reporting more trait physical aggression than females (M = 9.2) in the sample [F

(1,918) = 56.907, p < .001, η2 = .18].

Another SME was found for age-group [F (3,918) = 66.17, p < .001, η2 = .06].

Dunnetts’ C post hoc comparisons of the four age-groups revealed 17–24 year olds

reported significantly higher levels of physical aggression than the other three age

groups at p < .05. Although the means scores for physical aggression appear to reduce

as age increases, there was no statistically significant difference between 25–39 year old

(M = 11) and 40–59 year old drivers (M = 10.3), p > .05. Drivers aged 60 years plus

scored significantly less on the physical aggression subscale than all other drivers.

Verbal Aggression Subscale The overall ANOVA evaluating age and gender effects on trait verbal aggression

levels was significant [F (7,918) = 23.036, p < .001]. Significant SMEs were found for

age [F (3,918) = 46.654, p < .001, η2 = .13] and for gender [F (1,918) = 22.655,

p < .001, η2 = .02].

The gender SME revealed that male (M = 11.7) participants scored significantly

higher on verbal aggression than females (M = 10.5), p < .05. Using Dunnett’s C post

hoc comparisons, young drivers 17–24 years of age scored significantly higher on verbal

aggression than the other age groups under consideration (p < .05), whilst there was no

significant difference in the verbal aggression scores reported by 25–39 and 40–59 year

old drivers (p > .05). Older drivers, 60 years and over, also reported significantly less

trait verbal aggression than other age groups, p < .05. Similar to the trait physical

aggression scores, the means suggest that as age increases verbal aggression decreases.


Angry Aggression Subscale

The overall ANOVA evaluating age and gender effects on trait anger levels was

significant [F (7,918) = 26.296, p < .001]. A SME was found for age-group [F (3,918) =

54.113, p < .001, η2 = .15]. Dunnett’s C’s post-hoc comparisons revealed significantly

greater levels of angry aggression for 17–24 year olds than drivers aged 40 years and

over, (p < .05). However, there was no significant difference between self-reported

angry aggression for the 17–24 and 25–39 year old drivers, (p > .05).

Examination of the means suggests that as age increases angry aggression

decreases. Also, females aged 25–39 years (M = 10.9) reported more angry aggression

than males of the same age (M = 9). However, in all other age groups females reported

less angry aggression than males.

Hostile Aggression Subscale

The overall ANOVA was significant [F (7,918) = 31.047, p < .001]. SMEs were

found for gender [F (1,918) = 7.625, p < .006, η2 = .01] and age groups [F (3,918) =

64.682, p < .001, η2 = .17 ]. Examination of the means for males and females across the

age levels indicates that males report marginally higher levels of hostility than females,

consistent with the grand means, males (M = 16) and females (M = 15).

Posthoc comparisons examining differences between the age groups revealed

that 17–24 year olds scored significantly higher on hostile aggression than all other age

groups (p < .05). Conversely, participants aged 60 years and over scored significantly

lower than all other drivers, (p < .05). However, a significant difference was not found

between the 25–39 and 40–59 year olds on this subscale, (p > .05).

Social Problem Solving Subscales

The overall ANOVA for RPS was not significant, F (7,918) = 1.70, p = .105.

However, the ANOVAs for age group and gender by NPO and ICS problem solving

were significant [F (7,918) = 16.80, p < .001 and F (7,918) = 8.62, p < .001,

respectively]. Again, no significant interactions were reported for age group by gender.

Instead, several significant SMEs were found for age group by NPO and ICS [F (3,918)

= 17.84, p < .001, η2 = .06 and F (3,918) = 19.72, p < .001, η2 = .06, respectively]. Post

hoc comparisons revealed that 17–24 year olds reported significantly more NPO than all

other age groups, p < .05. However, there was no significant difference in NPO between


the 25–39 and 40–59 year old age groups, p > .05. Post hoc comparisons also revealed

that 17–24 year olds reported significantly higher levels of ICS than those aged 40 years

and over, p < .05. There was no significant difference between 17–24 year olds and 25–

39 year olds on levels of ICS, p > .05. Examination of the means indicates that as age

increases levels of NPO and ICS appear to decrease.

A significant SME was also found for gender by NPO, F (1,918) = 16.73, p <

.001. Females (M = 5.2) reported significantly higher levels of NPO (p < .05) than

males (M = 5), though the difference seems minute.


Appendix L PHA Driver results from the Study Two Sample

Table L1 Age group breakdown by driver group membership

Age Group

Significance Level1 17-24 Years 25-39 Years 40-59 Years 60 + Years Other drivers (n = 838)

290

34.6%

148

17.7%

204

24.3%

196

23.4%

χ2 (df3) = 16.157, p < .001, øc = .13

PHA Drivers (n = 88)

42

47.7%

9

10.2%

29

33%

8

9.1% 1. The cells with significant (p < .01) adjusted standardised residuals were bolded

Table L2 Gender breakdown by driver group membership

Female

Male

Significance Level1 Other drivers (n = 838)

531 63.4%

307 36.6%

χ2 (df1) = 24.361, p < .001, ø = .162


32 36.4%

56 63.6%

1. The cells with significant (p < .01) adjusted standardised residuals were bolded

Table L3 Education level by driver group membership

Education Attained

Significance

Level1 Primary/

Yr102 Senior (Yr12)

TAFE/Tech/ Apprentice

CAE/Uni

Other Drivers (n = 837)

148

17.7%

226

27%

214

25.6%

249

29.7%

χ2 (df3) = 12.672, p < .01, øc = .12


7

8%

35

39.8%

28

31.8%

18

20.5%

1. The cells with significant (p < .01) adjusted standardised residuals were bolded 2. Primary and Year 10 level education were collapsed to produce cell sizes of >5, as were TAFE, Technical College, Apprenticeship and ‘other’.


Table L4 Hours driven per week by driver group membership

Hours Driven Per Week

Significance Level1

0-5 hours

6-10 hours

11-15 Hours

16-20 hours

>20 hours


291

34.8%

345

41.2%

117

14%

44

5.3%

40

4.8%

χ2 (df4)= 5.583, p > .01, øc = .08


27

30.7%

30

34.1%

17

19.3%

7

8%

7

8%

Table L5 Type of vehicle driven by driver group membership

Type of Vehicle

Significance

Level1 Small Car Medium Car Large Car 4WD/Utility/Truck


260

32.2%

285

34.8%

145 18%

121 15%

χ2 (df3) = 10.254, p = .017, øc = .11


13

15.7%

34

41%

18

21.7%

18

21.7%

1. The cells with significant (p < .01) adjusted standardised residuals were bolded

Table L6 Traffic density exposure by driver group membership

Traffic Density

Significance Level

Light

Medium Heavy


121

14.7%

595

72.5%

105

12.8%

χ2 (df2) = 2.574, p = .276, øc = .05


10

11.6%

60

69.8%

16

18.6%

1. The measure in its original state had a number of cells less than 5 (see Appendix F). As such, the categories were collapsed to reflect a measure of light, medium and heavy traffic density, irrespective of type of road.


Table L7 Comparison of PHA drivers to other drivers on trait characteristics

Variables

M

SD

Mean Rank

Hostile Aggressive Drivers (n = 88)

Mean Rank

Other Drivers

(n = 838)

Mann-Whitney Test

Z scores

AQ Subscales Physical Aggression 10.48 5.16 697.59 438.92 -8.675, p < .001

Verbal Aggression 11.21 3.73 628.95 446.13 -6.120, p < .001

Angry Aggression 9.5 4.28 639.93 444.97 -6.526, p < .001

Hostile Aggression 15.77 5.91 623.63 446.68 -5.914, p < .001

AQ Total Scores 46.96 15.57 683.80 440.37 -8.124, p < .001

SPSI-R Subscales

Negative Problem Orientation

5.21

.52

540.97

455.37

-2.882, p < .017


5.16

.54

573.31

451.97

-4.081, p < .001


3.32

.87

408.07

469.32

-2.049, p > .017 Pre-questionnaire Negative Emotion

2.00

.77

590.10

450.21

-4.711, p < .001 Use of a conservative measure of significance was decided upon for interpreting the results to protect against family-wise error. Specifically, for the testing of the AQ subscales the chosen p < .01, was calculated using a Bonferoni Adjustment .05 ÷ 5 (number of subscales) = .01. Similarly, the significance level of the tests involving the SPSI-R subscales was pre-determined at p < .017.

Table L8 Number of crashes in past three years by driver type

Crashes in Past Three Years Significance Level

No Crashes

One Crash Two or More Crashes


630

75.6%

158 19%

45

5.4%

χ2 (df2) = 4.035, p = .133, øc = .07


60

68.2%

19

21.6%

9

10.2%

To facilitate the analysis of this data the number of crashes reported by participants was collapsed into three

categories.


Table L9 Number of speeding fines and other fines in the past three years by driver

type

Speeding Fines, Other Fines and Drink Driving Charges

in the Past Three Years

Significance Level

Speeding Fines

None

One

Two or Three

χ2 (df2) = 1.927, p = .381, øc = .05


589 72.7%

148 18.3%

73 9%


57

66.3%

18

20.9%

11

12.8%

Other Fines

No Fines One or More Fines


697

94.3%

42

5.7%

χ2 (df1) = 1.885, p = .170, ø = .05


65

90%

7

9.7%

Previous Drink Driving Charges

No Charges One or More

Other Drivers (n = 734) PHA Drivers (n = 73)

729

99.3%

70 95.9%

5

.7%

3 4.1%

χ2 (df1) = 7.951, p < .05, øc = .10

Table L10 Comparison of PHA drivers to other drivers on Behavioural Intentions

Variables

Mean Rank

PHA Drivers (n=74)

Mean Rank

Other Drivers (n=850)

Mann-Whitney Test

Z scores

Likelihood of Speeding 10km/h ≥ Urban Roads

542.7

455.5

-2.993, p < .05

10km/h ≥ Highways 583.6 453.1 -4.188, p < .001 Likelihood of Drink/Drug Driving

Drink Drive

535.7

456.1

-4.714, p < .001

Drug Drive

520

457.5

-5.127, p < .001


Table L11 Mann-Whitney U tests of Emotional, Cognitive and behavioural responses

to scenarios by group membership

Variables by Scenario

M

SD

Mean Rank


Mean Rank


Mann-Whitney

Test Z scores

Scenario 1

Negative Emotion 2.97 1.05 558.30** 453.54 -3.509, p < .001

Perceived Threat 2.53 1.31 471.93 462.62 -.319, p > .01

Negative Attributions 3.36 1.15 526.98 456.83 -2.353, p > .01

Instrumental Aggressive Response

1.96

.75

711.19**

437.49

-9.164, p < .001

Hostile Aggressive Response

1.07

.35

815.84**

426.50

-27.630, p < .001

Post-Event Influence 1.51 .74 556.91** 453.69 -3.695, p < .001

Scenario 2

Negative Emotion 2.5 1.1 570.78** 452.23 -3.973, p < .001

Perceived Threat 1.18 .52 557.44** 453.64 -5.725, p < .001

Negative Attributions 2.14 1.12 589.70** 450.25 -4.711, p < .001

Instrumental Aggressive Response

1.87

.73

698.69**

438.80

-8.702, p < .001

Hostile Aggressive Response

1.05

.30

639.67**

445.00

-19.142, p < .001 Post-Event Influence

1.25

.55

535.00**

455.99

-3.362, p < .001


Table L12 PHA driver group membership as a function of person-related, emotional, cognitive and behavioural responses and driving exposure variables

Variables

B

Std. Error

Wald Test

Odds Ratio

95% CI for Odds Ratio

Person-related Gender

-1.04

.35

9.01**

.36

.18

.70

Age1

25-39 years 40-59 years 60 years and over

-1.13 .29 -.25

.57

.41

.57

3.96** .50 .19

.32 1.34 .78

.12

.60

.26

1.07 2.97 2.39

Total AQ Score

.04

.01

7.7**

1.04

1.01

1.06

SPSI-R Subscales: NPO

-.14

.34

.16

.87

.44

1.71 ICS

.13

.31

.17

1.14

.62

2.09

RPS

-.26

.20

1.83

.77

.53

1.13

Education Attained2

.09

.49

.03

1.09

.42

2.86

Total Pre-study Emotion

.18

.23

.60

1.19

.77

1.85

Emotional, Cognitive & Behavioural Responses Negative Emotions

-.83

.28

8.80**

.44

.25

.76

Perceived Threat

.32

.19

7.18**

1.37

1.09

1.73

Negative Cognitions

-.38

.22

3.07

.68

.44

1.05

Instrumental VS Hostile Aggressive Responses

2.08

.32

42.86**

7.99

4.23

14.89

Driving Exposure Hours Driven Per Week3 6-10 hours

11-15 hours 16-20 hours More than 20 hours

-.13 .35 -.08 -1.79

.37

.46

.63

.98

.13

.57

.02 3.31

.88 1.42 .93 .17

.42

.58

.27

.02

1.81 3.48 3.16 1.15

Type of Vehicle4

Medium Large 4WD Truck/Ute

1.02 1.18 1.39 .98

.44 .52 .57 .73

5.50* 5.18* 5.93*

1.80

2.78 3.25 4.00 2.67

1.18 1.18 1.31 .63

6.53 8.96

12.20 11.27

Congestion Exposure5

Medium Heavy

.29

.59

.51

.62

.31

.93

1.33

1.81

.49

.54

3.62

6.1

1. Age reference group = 17-24 years. 2. Education as a dichotomous variable: 0 < Year 10 & 1 > Year 10. 3. Type of vehicle reference group = small vehicle. 4. Hours driven per week reference group = 0-5hours. 5. Congestion exposure reference group = light. * p<.05 ** p<.01


Appendix M: Semi-Structured Questionnaire – Study Three

Stage One – Aggressive Driving Project

The following information is personal in nature, however, it is necessary in order for this research to increase our understanding of aggressive driving behaviour. Please be assured that no person, other than the researcher involved, will have access to the information you provide.

First Name: ____________________________________________________

Age (in years): _____________________________________________


The first of our questions are about you and your driving. Please circle one number to show your answer for each question. Remember – all the information you provide is completely confidential and your anonymity is absolutely assured. If you decide you don’t want to answer a question, that is OK. Please just go on to the next question.

1. What type of vehicle do you drive most often? Please circle one number only.

Small car…………..………………………………… Medium car………………….……………………… Large car………….………………………………… 4WD…………………………………………………. Utility/ truck…………………………………… Motorcycle…………………………………………... Van/people mover/mini-bus………………………. Other (please specify _____________________)

1 2 3 4 5 6 7 8

2. Where do you most often drive your vehicle? Please circle one number only.

City/Town roads light traffic…………………….…. City/Town roads medium traffic…………….…….. City/Town roads heavy traffic…………………….. Highways/open roads light traffic…………………. Highways/open roads medium traffic……………. Highways/open roads heavy traffic……………….

1 2 3 4 5 6

3. How many hours do you usually drive a vehicle per week? Please circle one number only.

0-5…………………………….. 1 6-10…………………………… 2 11-15…………………………… 3 16-20……….…………………. 4 More than 20……………………5

4. During the last 3 years, how many crashes have you been involved in

(irrespective of whether you were considered at fault or not)?

______________________(write in the number)

A “crash” involves damage

occurring to a

vehicle/vehicles or property,


5. Have you been booked for any traffic

related offences (not parking tickets) during the

last 3 years?

(Please write in the number of offences.)

Speeding .................................................................. Drink driving.............................................................. Driving without a valid Licence .................................

6. Please circle the appropriate response to the following questions.

How likely are you to drive when you think you might be over the legal alcohol limit?……………….

How likely are you to drive under the influence of recreational drugs?……………………………………

Not at all Extremely Likely Likely

1 2 3 4 5

1 2 3 4 5

7. What is your highest level of formal education you have completed?

Primary ........................................................................ 1 Junior (Grade 10) ........................................................ 2 Senior (Grade 12) ........................................................ 3 TAFE/Tech College/Apprenticeship ............................ 4 CAE/University ............................................................ 5 Other (Please specify) ________________________ 6

8. What is your marital status?

Single .......................................................................... 1 Married ........................................................................ 2 Defacto ........................................................................ 3 Separated .................................................................... 4 Divorced ...................................................................... 5

9. How many years have you been driving? 1 – 2 YEARS ............................................................... 1 3 – 5 YEARS ............................................................... 2 6 - 10 YEARS .............................................................. 3 11 - 15 YEARS ............................................................ 4 15 - 20 YEARS ............................................................ 5 OVER 20 YEARS ........................................................ 6

10. Approximately, what is your annual income? $0 - 10 000 .................................................................. 1 $11 000 - 20 000 ......................................................... 2 $21 000 – 30 000......................................................... 3 $31 000 – 40 000......................................................... 4 $41 000 – 50 000......................................................... 5 $51 000 – 60 000......................................................... 6 $61 000 – 70 000......................................................... 7 ABOVE $70 000 .......................................................... 8


11. Have you ever visited a psychologist or psychiatrist? If so, please briefly outline the reason. …………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………


Stressful Life Experiences We are interested in learning about your experiences. Below is a list of experiences that some people have found stressful. Please fill in the number that best represents how much the following statements describe your experiences. If you are not sure of your answer, just give us your best guess.

0 1 2 3 4 5 6 7 8 9 10

I did not experience

A little like

my experiences

Somewhat

like my experiences

Exactly like my

experiences

Describes Experience

Life Experience

I have witnessed or experienced a natural disaster; like a hurricane or earthquake.

I have witnessed or experienced a human made disaster like a plan crash or industrial disaster.

I have witnessed or experienced a serious accident or injury.

I have witnessed or experienced chemical or radiation exposure happening to me.

I have witnessed or experienced a life threatening illness happening to me, a close friend or a family member.

I have witnessed or experienced the death of my spouse or child.

I have witnessed or experienced the death of a close friend or family member (other than my spouse or child).

I or a close friend or family member has been kidnapped or taken hostage.

I or a close friend or family member has been the victim of a terrorist attack or torture.

I have been involved in combat or a war or lived in a war affected area.

I have seen or handled dead bodies other than at a funeral.

I have felt responsible for the serious injury or death of another person.

I have witnessed or been attacked with a weapon in a family setting.

As a child/teen I was hit, spanked, choked or pushed hard enough to cause injury.

As an adult, I was hit, choked or pushed hard enough to cause injury.

As an adult or child, I have witnessed someone else being choked, hit, spanked, or pushed hard enough to cause injury.

As a child/teen I was forced to have unwanted sexual contact.

As an adult I was forced to have unwanted sexual contact.

As a child or adult I have witnessed someone else being forced to have unwanted sexual contact.

I have witnessed or experienced an extremely stressful event not already mentioned. Please briefly explain:……………………………………………………………………………………………


Aggression Questionnaire

Please circle the number which best indicates how characteristic the following statements are about you, from‘1’ Extremely Uncharacteristic to ‘5’ Extremely characteristic. Extremely Extremely

Uncharacteristic Characteristic

If somebody hits me, I hit back 1 2 3 4 5

I tell my friends openly when I disagree with them 1 2 3 4 5

When frustrated, I let my irritation show 1 2 3 4 5

There are people who pushed me so far that we came to blows 1 2 3 4 5

I am sometimes eaten up with jealousy 1 2 3 4 5

When people annoy me, I may tell them what I think of them 1 2 3 4 5

I am an even tempered person 1 2 3 4 5

At times I feel I have gotten a raw deal out of life 1 2 3 4 5

Once in a while I can’t control the urge to strike another person 1 2 3 4 5

I often find myself disagreeing with people 1 2 3 4 5

I flare up quickly but get over it quickly 1 2 3 4 5

Some of my friends think I’m a hothead 1 2 3 4 5

Other people always seem to get the breaks 1 2 3 4 5

Given enough provocation, I may hit another person

1 2 3 4 5

I can’t help getting into arguments when people disagree with me 1 2 3 4 5

I wonder why sometimes I feel so bitter about things

1 2 3 4 5

If I have to resort to violence to protect my rights, I will

1 2 3 4 5

I have trouble controlling my temper 1 2 3 4 5

I can think of no good reason for ever hitting a person

1 2 3 4 5

I know that “friends” talk about me behind my back

1 2 3 4 5

My friends say that I’m somewhat argumentative 1 2 3 4 5


I sometimes feel like a powder keg ready to explode

1 2 3 4 5





Sometimes I fly off the handle for no good reason

1 2 3 4 5

I sometimes feel that people are laughing at me behind my back 1 2 3 4 5

I have become so mad that I have broken things

1 2 3 4 5

I get into fights a little more than the average person

1 2 3 4 5

When people are especially nice, I wonder what they want

1 2 3 4 5


Social Problem Solving Inventory - Revised The following questions look at how you generally think and feel about problems and how you might solve them. In this questionnaire, a problem is something important in your life that bothers you a lot, but you don’t immediately know how to make it better or stop it from bothering you so much. The problem could be something about yourself (such as your thoughts, feelings, behaviour, health, or appearance), your relationships with other people (such as your family, friends, teachers or boss), or your environment and the things you own (such as your house, car, property or money). Please read each statement carefully and choose one of the numbers below that best shows how much the statement is true of you. See yourself as you usually think, act and feel when you are faced with important problems in your life these days. Not at all

True of Me Slightly True of

Me

Moderately True of Me

Very True of

Me

Extremely True of Me

I feel threatened and afraid when I have an important problem to solve.

1

2

3

4

5

When making decisions, I do not evaluate all my options carefully enough.

1

2

3

4

5

I feel nervous and unsure of myself when I have an important decision to make.

1

2

3

4

5

When my first efforts to solve a problem fail, I get very frustrated.

1

2

3

4

5

When I am faced with a difficult problem, I doubt that I will be able to solve it on my own no matter how hard I try

1

2

3

4

5

Difficult problems make me very upset.

1

2

3

4

5

When I have a decision to make I try to predict the positive and negative consequences of each option.

1

2

3

4

5

When I am trying to solve a problem, I go with the first good idea that comes to mind.

1

2

3

4

5

When I have a problem to solve, one of the first things I do is get as many facts about the problem as possible.

1

2

3

4

5

Before I try to solve a problem, I set a specific goal so that I know exactly what I want to accomplish.

1

2

3

4

5

When I have a decision to make, I do not take the time to consider the pros and cons of each option.

1

2

3

4

5

After carrying out a solution to a problem, I try to evaluate as carefully as possible how much the situation has changed for the better.

1

2

3

4

5

When I am trying to solve a problem, I think of as many options as possible until I cannot come up with any more ideas.

1

2

3

4

5

When making decisions, I go with my “gut feeling” without thinking too much about the consequences of each option.

1

2

3

4

5

I am too impulsive when it comes to making decisions. 1 2 3 4 5


Barratt Impulsiveness Scale -11 (Barratt & Patton, 1995) Directions: People differ in the ways they act and think in different situations. This is a test to measure some of the ways in which you act and think. Read each statement carefully and DARKEN THE APPROPRIATE CIRCLE to the right of the statement. Answer quickly and honestly.

Rare

ly / N

ever

Oc

casio

nally

Of

ten

Al

most

Alwa

ys

1. I plan tasks carefully ……………………………………………………….. 2. I do things without thinking ………………………………………………… 3. I make up my mind quickly ………………………………………………… 4. I am happy-go-lucky ……………………………………………………….. 5. I don’t “pay attention” ………………………………………………………. 6. I have “racing” thoughts ……………………………………………………. 7. I plan trips well ahead of time ………………………………………………. 8. I am self-controlled …………………………………………………………. 9. I concentrate easily ………………………………………………………….. 10. I save regularly …………………………………………………………….. 11. I “squirm” at plays or lectures ……………………………………………... 12. I am a careful thinker ……………………………………………………… 13. I plan for job security ……………………………………………………… 14. I say things without thinking ………………………………………………. 15. I like to think about complex problems …………………………………… 16. I change jobs ………………………………………………………………. 17. I act “on impulse” …………………………………………………………. 18. I get easily bored when solving thought problems ………………………... 19. I act on the spur of the moment ……………………………………………. 20. I am a steady thinker ………………………………………………………. 21. I change where I live ………………………………………………………. 22. I buy things on impulse ……………………………………………………. 23. I can only think about one problem at a time ……………………………… 24. I change hobbies …………………………………………………………… 25. I spend or charge more than I earn ………………………………………… 26. I have outside thoughts when thinking ……………………………………. 27. I am more interested in the present than the future ……………………….. 28. I am restless at lectures or talks …………………………………………… 29. I like puzzles ………………………………………………………………. 30. I plan for the future ………………………………………………………...


Carlson Psychological Survey (Carlson, 1982)

INSTRUCTIONS: Put an X for the one correct answer to each question.

COMMENTS 1. I drink alcohol:

1) _____ never 2) _____ once in a while 3) _____ about once a week 4) _____ more than once a week 5) _____ all the time

2. My thinking is: 1) _____ good, straight 2) _____ good, but a little mixed-up 3) _____ mixed-up but I can do O.K. 4) _____ mixed-up 5) _____ my head is all mixed-up

3. I trust: 1) _____ everyone 2) _____ most people 3) _____ some people but not others 4) _____ only my best friends 5) _____ no one

4. My life is: 1) _____ very interesting 2) _____ interesting 3) _____ both interesting and dull 4) _____ dull 5) _____ always boring and dull

5. I feel: 1) _____ O.K. 2) _____ a little down, but O.K. 3) _____ sad some of the time 4) _____ sad a lot of the time 5) _____ really sad and depressed

6. I would use a weapon to rob someone: 1) _____ never 2) _____ almost never 3) _____ maybe 4) _____ would do it 5) _____ have done it and would do it again

7. I have used drugs: 1) _____ never 2) _____ once or twice 3) _____ some of the time 4) _____ most of the time 5) _____ all the time


8. I see or hear things that are not there: 1) _____ never 2) _____ once or twice 3) _____ more than once or twice 4) _____ often 5) _____ many times

9. I have told others off: 1) _____ never 2) _____ once or twice 3) _____ more than once or twice 4) _____ often 5) _____ many times

10. I think my future will be: 1) _____ very good 2) _____ pretty good 3) _____ not too bad 4) _____ bad 5) _____ nothing ever went right and nothing ever will

11. I speak English and: 1) _____ no other languages 2) _____ 1 or 2 other languages 3) _____ 3 or 4 other languages 4) _____ 5 or 6 other languages 5) _____ 7 or more other languages

12. My nerves are: 1) _____ pretty good 2) _____ average 3) _____ jumpy but O.K. 4) _____ very poor 5) _____ shot

13. In school, I have caused trouble: 1) _____ never 2) _____ once or twice 3) _____ 3 or 4 times 4) _____ 5 or 6 times 5) _____ more than 7 times

14. The last time I got into trouble, I had: 1) _____ not been drinking or had not had drugs at all 2) _____ only had a little 3) _____ had a fair amount 4) _____ had too much 5) _____ had so much I did not know what I was doing

15. When I watch a T.V. show, I can understand what is going on: 1) _____ always 2) _____ almost all the time 3) _____ much of the time 4) _____ some of the time 5) _____ never

16. When I was younger, the police picked up:


1) _____ none of the my friends 2) _____ one or two of my friends 3) _____ some of my friends 4) _____ most of my friends 5) _____ all of my friends

17. Compared to other people, I have: 1) _____ a lot less problems 2) _____ less problems 3) _____ about the same number of problems 4) _____ more problems 5) _____ many more problems

18. In the future, I will drink alcohol, or take drugs: 1) _____ never 2) _____ once in awhile 3) _____ once a week 4) _____ 2 or 3 times a week 5) _____ more than 3 times a week

19. Physically, my body and health are: 1) _____ perfect 2) _____ very good 3) _____ pretty good 4) _____ not too good 5) ______ poor

20. The staff in this place are: 1) _____ nice and helpful 2) _____ helpful 3) _____ O.K. 4) _____ not too bad 5) _____ stupid

21. Most people seem to think I am: 1) _____ a very good person 2) _____ a bit better than others 3) _____ just like everyone else 4) _____ a bit worse than others 5) _____ a very bad person

22. I believe that drugs have made me think and do: 1) _____ I do not use drugs 2) _____ bad things 3) _____ have no effect on me 4) _____ better things than I usually do 5) _____ very good things

23. I have trouble remembering the names of my friends: 1) _____ never 2) _____ once in awhile 3) _____ some of the time 4) _____ most of the time 5) _____ all the time


24. I have been in gang fights: 1) _____ never 2) _____ never but wish I had 3) _____ once 4) _____ 2 or 3 times 5) _____ more than 3 times

25. I think I do the best thing: 1) _____ all the time 2) _____ almost all the time 3) _____ much of the time 4) _____ some of the time 5) _____ once in awhile

26. I have lived in this country and: 1) _____ no other country 2) _____ 1 or 2 other countries 3) _____ 3 or 4 other countries 4) _____ 5 or 6 other countries 5) _____ 7 or more other countries

27. I change from happy one minute to sad the next: 1) _____ never 2) _____ once in awhile 3) _____ some of the time 4) _____ most of the time 5) _____ all the time

28. I enjoy fighting: 1) _____ not at all 2) _____ a little 3) _____ some 4) _____ much 5) _____ very much

29. Most of my friends drink alcohol: 1) _____ never 2) _____ once in awhile 3) _____ about once a week 4) _____ more than once a week 5) _____ all the time

30. People I know seem like stranger to me: 1) _____ never 2) _____ once in awhile 3) _____ some of the time 4) _____ most of the time 5) _____ all the time

31. When I think about illegal things I have done, I am: 1) _____ very sorry 2) _____ sorry 3) _____ some of the time 4) _____ most of the time 5) _____ all the time


32. People seem to like it better when: 1) _____ I talk a lot 2) _____ I talk a little 3) _____ I am there but do not bother them 4) _____ I just listen 5) _____ I am not there

33. When I think about my problems, I: 1) _____ know they will work out 2) _____ never think about them or have no problems 3) _____ worry a little 4) _____ worry a lot 5) _____ get so scared I feel sick

34. If someone tried to cheat me, I would: 1) _____ forgive and forget 2) _____ forgive but not forget 3) _____ not forgive them 4) _____ make him sorry 5) _____ make him very sorry

35. Most of the time I sleep: 1) _____ every night 2) _____ twice a week 3) _____ once a week 4) _____ almost never 5) _____ never

36. Dreams have made me wake up in the middle of the night: 1) _____ never 2) _____ once or twice 3) _____ 3 or 5 times 4) _____ more than 5 times 5) _____ I wake up every night

37. If someone hit me, I would: 1) _____ I do not know what I would do 2) _____ go away or ask him why he did it 3) _____ hit him once 4) _____ hit him several times 5) _____ beat him up

38. Most of my best friends use drugs: 1) _____ never 2) _____ once or twice 3) _____ some of the time 4) _____ most of the time 5) _____ all the time

39. I forget what I was going to say: 1) _____ never 2) _____ once in awhile 3) _____ some of the time 4) _____ most of the time 5) _____ all the time


40. I think: 1) _____ all laws are good 2) _____ most laws are good 3) _____ laws are good and bad 4) _____ many laws are bad 5) _____ all laws are bad

41. When I do things, I do them: 1) _____ very good 2) _____ good 3) _____ better than average 4) _____ average 5) _____ poor

42. Little things worry me: 1) _____ never 2) _____ once in awhile 3) _____ some of the time 4) _____ most of the time 5) _____ all the time

43. If I hurt someone, I would feel: 1) _____ very bad 2) _____ bad 3) _____ bad but not too bad 4) _____ depends on the person and how it would feel 5) _____ would not care

44. When I am drunk or on drugs, I: 1) _____ do not get drunk or take drugs 2) _____ never get into trouble 3) _____ try not to get into trouble 4) _____ sometimes get into trouble 5) _____ always get into trouble

45. I will be in trouble: 1) _____ never again 2) _____ do not want to be again 3) _____ do not want to be but probably will be again 4) _____ once or twice more 5) _____ for the rest of my life

46. The drug I have taken the MOST is: 1) _____ no drugs 2) _____ marijuana or hashish 3) _____ LSD or drugs like LSD 4) _____ speed or drugs like speed 5) _____ heroin or drugs like heroin

47. I feel sick: 1) _____ never 2) _____ once in awhile 3) _____ some of the time 4) _____ most of the time 5) _____ all the time


48. I get a kick out of seeing someone put down: 1) _____ never 2) _____ once in awhile 3) _____ some of the time 4) _____ most of the time 5) _____ all the time

49. My life has been: 1) _____ better than most peoples 2) _____ as good as most peoples 3) _____ average 4) _____ as bad as most peoples 5) _____ worse than most peoples

50. I have carried a weapon on me: 1) _____ never 2) _____ once or twice 3) _____ some of the time 4) _____ most of the time 5) _____ all the time

12. Have you been booked for any offences as a result of driving? If so, please provide brief details. ………………………………………………………………………………………………………………………. ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… 13. Have you been booked for any offences that have not been related to driving? If so, please provide brief details. ……………………………………………………………………………………………………………………….. ………………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………………. ……………………………………………………………………………………………………………………….

THANK YOU FOR YOUR PARTICIPATION SO FAR. YOU MAY HAVE A SHORT BREAK IF YOU WISH, AND THEN WE SHALL

CONDUCT THE INTERVIEW WHERE YOU WILL BE GIVEN THE OPPORTUNITY TO DISCUSS YOUR EXPERIENCE WITH AGGRESSIVE

DRIVING.


Appendix N: Interview Protocols – Study Three

Stage Two

Protocol for Interviewing Aggressive Driving Case Studies

Thanks for your continued support of this research project. For the purpose of

this stage of the research you are asked to recall one of your most vivid experiences with aggressive driving behaviour. During the last 12-18 months you need to have been so angry on the road that you verbally or physically abused another driver, or you have been really angry and jumped in your car, driving off to let off steam. As a result of this action, you must have left your vehicle and verbally or physically abused the other road user, and/or caused property damage.

Could you tell me about the incident?

Probes:

• How were you feeling immediately before the incident?

• Had you been drinking or taking recreational drugs prior to this incident?

• What feelings did you experience?

• Why did you behave the way you did?

• Specifically, what was it that prompted your feelings?

• Can you describe how you were feeling within your body at the time?

• Did you intend to aim your behaviour at the other driver?

• Can you recall having any particular ‘thoughts’ while it was happening?

• Can you recall whether anything major or important was happening in

your life at the time of the incident?


• Have you ever been involved in such an on-road incident before?

Can you recall how the other driver reacted to your behaviour?

Probes:

• What went through your mind at this point?

o Did you feel guilty/ or remorseful?

o Did you feel that your actions were justified?

Do you think this incident affected your behaviour once you left the road?

Probes:

• How did this affect your behaviour?

Would you consider that your behaviour could be interpreted as aggressive?

_____________________________________________________________________

If you are interested, a follow-up appointment can be made to receive some feedback

concerning the questionnaires you completed earlier.

(obtain participant permission to contact them for follow-up interview)


Appendix O: Advertisement for Recruiting – Men’s Information and Support Association

Are you a real Hot-head behind the wheel?

• Have you ever felt so angry on the roads that you have ‘lashed out’ at another driver?

OR

• Have you ever felt really angry and jumped in the car and driven off just to let off ‘steam’? AND

• Did your actions involve verbally or physically abusing another

driver?

Would you like to earn $$$ for 1 ½ hours of your time, participating in road safety research about aggressive driving?

If you answered ‘yes’ to all of these questions, we would like to talk to you. Please ring 3864 4685 and speak to Sharon from CARRS-Q, QUT, or leave your first name and contact number with staff on this number and she will be in touch shortly. Alternatively, email her on [email protected].


Appendix P: Participant Consent Package - Study Three

Welcome to the CARRS-Q Driving Behaviour Research

Dear Participant, The information gathered via your involvement in this project, will form part of the data required for completion of the researcher’s Doctoral thesis. The project is examining person-related and situational factors that may influence the expression of aggression on the road. In order to participate, you must hold a current driver’s licence and be able to recall an on-road incident where you were either physically or verbally abusive toward an unknown driver. Today’s process involves two stages, completion of a series of questionnaires with the aid of the researcher and an interview. Participants are requested to answer the questions to the best of their ability. The questionnaires should take approximately 1hour to complete. After a short break, you will be asked to recall one of your most vivid experiences with aggression on the road. This interview should take approximately 30 minutes. You will then be financially reimbursed for your time and travelling expenses to the value of $60.00. Please note, that information provided by you will be anonymous and treated as strictly confidential. All records will be maintained in a locked filing cabinet accessible only to the researcher. Participation in this research is voluntary and you are free to withdraw from the study at any time. If the interview questions cause you any discomfort, you are free to contact QUT Counselling and Health Services, by phoning 3864 4539, who have been informed about this study as a precaution and will provide counselling support, free of charge. Following the completion of the questionnaires, if you have any queries I can be contacted on the number above or via email. If you have any concerns about the ethical conduct of this research please contact the Secretary, University Human Research Ethics Committee on 3864 4902. The results of the following questionnaires shall be discussed with you during the next stage of the research, if you are interested.

Yours faithfully,

Sharon O’Brien



• have read the information provided above; • understand that you are able to withdraw from this study at any time without

explanation; • understand that any information you provide will be treated as strictly confidential; • understand that the interview stage of the research shall be taped using a recording

device; • consent to participate in the research described above; and • are aware that you shall be paid $60.00 upon completion of the second stage of the

project (ie., the interview).

Participant’s Name Signature of Participant

Date


Appendix Q: Published M and SD Associated with the CPS and BIS-11 Measures

Table Q1 CPS norms for female and male offenders (Carlson, 1982, p. 6)

Age Chemical

Abuse

(α=.91)

Thought

Disturbance

(α=.92)

Antisocial

Tendencies

(α=.89)

Self-Depreciation

(α=.87)

Validity

(α=.49)

N

M

SD

M

SD

M

SD

M

SD

M

SD

M

SD

Female

311

20.1

2.7

23.2

6.4

30.4

7.8

32.4

9.2

20.5

4.9

3.55

.81

Male

412

19

3.3

24

7.1

29

8.3

36.3

9.9

20.6

5.4

3.8

1.2

• All figures rounded

Table Q2 Descriptive statistics and internal consistency coefficients for total BIS-11 scores on four samples (Patton, Stanford & Barratt, 1995)

Males

Females Total Group

Group

M SD M SD M SD

Undergraduates 64.94d 10.19 63.32b,c 10.16 63.82b,c 10.17

Substance-abuse Patients 69.00 d 10.21 69.78a 10.51 69.26 a 10.28

General Psychiatric Patients 69.74 d 11.54 72.78a 13.43 71.37 a 12.61

Prison Inmates 76.30a,b,c 11.86 a Differs significantly from Undergraduates (p<.05) b Differs significantly from Substance Abuse Patients (p<.05) c Differs significantly from General Psychiatry Patients (p<.05) d Differs significantly from Prison Inmates (p<.05)


Table Q3 General population means and standard deviations of the BIS-11 subscales (N = 245) (Miller, Joseph & Tudway, 2004)

BIS-11 Subscales

M SD

Consistency Coefficient

α Motor Impulsivity

22.4

4.46

.70

Non-Planning Impulsivity

24.23

4.99

.72

Cognitive Impulsivity

16.53

3.30

.61


Appendix R: Range of CPS Subscale Scores by Offender Type (Carlson, 1982)

Type 1

Applicable Range of Scores

Chemical Abuse 27-37

Thought Disturbance 20-29

Anti-social Tendencies 30-39

Self-Depreciation 18-24

Validity 3-4

Descriptive Summary Drug and alcohol abuse is a major characteristic of the group. Although some of

these individuals are concerned about getting into trouble again, they exhibit little motivation toward bettering themselves. Others deny any drug/alcohol problems and do not appreciate the severity of their situations, maintaining a matter-of-fact attitude toward the negative aspects of their past.

This type is generally seen as sociable and friendly, with few apparent hostile behaviours. However, many have a quick temper that may result in impulsive and destructive behaviour.

Type 2






Validity 3-4

Descriptive Summary These individuals display an array of passive-aggressive features. They are described as likable and friendly, yet they are also irresponsible, immature and sometimes hostile. A major problem in the home environment appears to be a lack of communication and guidance by parents. The individual of this type may have average


intelligence and possess good abilities. However, because of poor motivation, their abilities are not used often for constructive purposes. These individuals also seem to be sympathetic to the criminal way of life and are usually involved with socially unacceptable peer groups. They use these gangs to gain recognition and tend to be followers rather than leaders.

Type 3






Validity 3-5

Descriptive Summary These individuals are usually described as immature and rebellious but not decidedly anti-social. They commonly look for support from their peers and get into trouble while looking for this approval if they think some anti-social act will be looked upon with favour. That is, their offences are generally unplanned, impulsive reactions to situations with little financial gain.

They are restless and, although they may start a project with great enthusiasm, their interest quickly fades and they are unable to complete a task. At that time, they may consider themselves confused and in need of assistance but within a few days, they are involved in a new project. Generally their motivation for change is crisis limited.

Type 4






Validity 3


Descriptive Summary A major characteristics of this individual is his severe family problems. Discipline or the lack of it may be a major contributor to this type’s criminal activities. They were considered to be troublemakers at school with attendance being somewhat irregular. Motivation for achievement is marginal. Immature personality is also characteristic of this type along with restlessness, foolishness and poor judgement.

Type 5






Validity 3-5

Descriptive Summary The individuals of this type are markedly antisocial. Their social adjustment has been poor, demonstrating difficulties in relating to others. Real contacts are therefore seldom made. They may on the surface appear as cooperative and charming, however, beneath this exists characteristics of impulsivity, intolerance, hostility, aggression and irritational behaviours. Depression is also apparent along with feelings of inferiority and inappropriate affect. It is thus not uncommon for some of these individuals to entertain suicidal thoughts.

Type 6






Validity 3-4


Descriptive Summary A passive-aggressive personality is indicative of this group. They are cooperative, friendly, relate well with peers, are lacking in ambition and are somewhat lazy. However, under the influence of alcohol they become belligerent, argumentative and physically aggressive. Most realize that personal problems exist, yet there is little or no motivation toward treatment. This group shows no remorse for their offences, often denying responsibility for what happened.

Type 7






Validity 3-5 Descriptive Summary These individuals reflect a disturbed personality and psychiatric treatment is often recommended. They are immature and emotionally labile. This group is very dependent on others and desperately need attention and emotional support; at the same time they drive people away by being so irrational and demanding. Hypochondria is often present in this type. Somatizations in response to life’s pressures are displayed in the form of constant recurring pains. Judgement is poor and guidance is needed in order to control impulses.

Motivation for treatment is low. They accept their behaviour on a superficial level but recurring troubles may cause them to withdraw and become passive. They lack purpose or direction of concern and they themselves see little hope for the future. Their self-image is poor and they suffer from guilt, despair, anxiety, depression and a confirmed state of mind. Suicide attempts are not uncommon in this type, but these may only be a means of seeking attention rather than a true attempt at death.


Type 8






Validity 3-4

Descriptive Summary These individuals are marked by chemical (drug) abuse which may have resulted in some brain damage. Home life was unsettled with hostility and resentment being shown toward the father. Poor peer relationships were made which resulted in these individuals being badly influenced by their associates. Prognosis for the future is poor as this type lacks responsibility and interest. Recidivism is therefore high for this group.

Type 9






Validity 3-4

Descriptive Summary Despite the fact that these individuals come from stable and good home environments, they do display elements of emotional instabilities. There are apparent feelings of inferiority and insecurity and there is the tendency to try to impress others around them. They are somewhat passive, shy, serious minded and cooperative yet they do display some negative type behaviours such as doing things for no apparent reasons. There may also be elements of dangerous or hostile behaviour existing. There are also some guilt feelings displayed over the offence.


Type 10






Validity 4-7

Descriptive Summary These individuals generally come from a good home environment where there was lots of family support. Their social adjustment has been good and they are friendly and cooperative with authorities. There may be a slight degree of pessimism and critical outlook. However this is likely to be situational.

Type 11


Chemical Abuse 9-19




Validity 3-4

Descriptive Summary This type generally is described as emotionally passive but having a favourable long term prognosis. They can be short-tempered but it is usually their impulsivity and associations with undesirable characters that gets them into trouble. Those of this type are at times restless and may display some immature and strange behaviour but they usually they present as pleasant and cooperative individuals.


Type 12






Validity 3-4

Descriptive Summary Those from this type come from a non-supportive home environment which resulted in a poor attitude toward the family, especially the father. They were a discipline problem in school, especially resenting male authority. These individuals seek affection and attention and a common way of achieving this is through superficial suicide attempts and temper tantrums.

They tend to be self-righteous in nature, assuming that they are always right and everyone else is wrong. Elements of immaturity, irresponsibility, non-motivation and instability are also present.

Type 13






Validity 3-4

Descriptive Summary This type presents himself as the victim of circumstances rather than the offender. He rationalizes the offence and denies any guilt for it, with an excuse ready for each crime committed. They are self-centered and do not listen to criticism or advice. Their judgement is faulty and so is their impulse control, making them easy targets for manipulative peers.


Feelings of insecurity, lack of identity, emotional immaturity and dependence are also characteristics of this type. There is little insight, no ambition toward future goals, and they are polite, cooperative and sometimes shy and quiet. Many of this type have difficulties in understanding and directing their sexual desire. Sexual maladjustments such as homosexuality are apparent in this type.

Type 14






Validity 5-7

Descriptive Summary Violence and aggressive behaviour are markedly characteristic of this type of individual. Under stress, they tend to go into a panic reaction which leads to the aggressive behaviour toward others as well as themselves. There is little emotional involvement in the offence and they are quick to rationalize these behaviours to themselves.

They suffer from a weak, immature personality and there is a serious lack of foresight or responsibility. There is a history of drug abuse which may have begun as a result of emotional problems in the past.

Type 15






Validity 5-7


Descriptive Summary These individuals are described as having inadequate personality disorders. In some cases there are indications of minimal brain damage. They are irritable, get mad quickly, are impulsive, irresponsible and their behaviours are difficult to predict. They have an anxious temperament and there is a nervousness or fear when they are around people.

Temper tantrums, aggressiveness and some violence are also characteristic of this type. In reality, this toughness may be just a front as they do suffer from a lack of self-confidence with feelings of inferiority and insecurity. They find it difficult to adapt to rules and regulations. There are indications however, that offences are committed so that they will be arrested and returned to a safe place such as the jail or institution. This may in part be a result of an unhappy and difficult home life where they were beyond the control of parents.

Type 16






Validity 3-4

Descriptive Summary A negative or ‘don’t give a damn’ attitude is predominant for those of this type. They do not want or foresee any change nor do they care about themselves or what happens to them. They are immature, explosive, irresponsible and short tempered resulting in violent behaviour if provoked. Their belief is that one must establish one-self through muscle power. They are thus contemptuous of others and have little regard for anyone else’s feelings. They identify with a value system of revenge, fighting, and hate for authority (especially that of males).

They are usually a product of a broken, pathetic and disturbed home situation. There is also a history of excessive drug and alcohol abuse. These individuals usually lack insight into their problems and refuse to believe that any do exist, making any type of treatment difficult.


Type 17






Validity 3-5

Descriptive Summary Alcohol and drug abuse is predominant for this type. Their home life was generally stable, although some of these individuals become too dependent on their families. They are immature, antisocial and lack perseverance in their work.

Type 18






Validity 3-4

Descriptive Summary These individuals are usually described as quiet and passive. They feel uncomfortable around other people and may use drugs or alcohol to be more sociable. When depressed they will drink excessively. Attempted suicides have been reported for those in this type. Relationships with teachers, school peers and authority figures are poor.


Appendix S: Brief Descriptor of Carlson Psychological Survey Offender Type

Brief Descriptors

Carlson Psychological Profile (Gavin Palk & Sharon O’Brien, 22 Mar 05)

Type

Keyword Descriptor

1 Poor insight and Substance abuser

2 Irresponsible

3 Immature and Rebellious

4 Immature, troublemaker

5 Markedly antisocial

6 Passive-aggressive

7 Disturbed Personality

8 Dysfunctional/problematic

9 Insecure/Inferiority

10 Socially well adjusted

11 Impulsive/Short tempered

12 Self-righteous and Attention seeking

13 Self-centered

14 Violent/Aggressive

15 Inadequate Personality Disorder

16 Negative/Explosive

17 Immature/Substance abuser

18 Depressed


Appendix T: Individual Participant Scores on the AQ and SPSI-R and Significance Levels – Study Three

*significant at p<.05 (two tailed) a b c d e f g h Individual participant scores compared to the hostile aggressive driver group (n=88) scores: AQ, M=62.32, SD=19.47; Verbal Aggression, M=13.63, SD=3.91; Physical Aggression, M=16.42, SD=7.23; Angry Aggression, M=12.66, SD=5.01; Hostile aggression, M=19.61, SD=6.49; NPO, M=5.33, SD=.5; ICS, M=5.38, SD=.58; RPS, M=3.16, SD=.74.

Case Number

Total AQ

Scorea

Z Score

Verbal Aggression

Scoreb

Z Score

Physical Aggression

Scorec

Z Score

Angry Aggression

Scored

Z Score

Hostile Aggression

Scoree

Z Score

NPO Scoref

Z Score

ICS Scoreg

Z Score

RPS Scoreh

Z Score

1

50 -.634 8 -1.44 21 .63 13 .068 8 -1.79 5 -.066 6 1.07 3 -.216

2

124 3.17* 25 2.91* 36 2.69* 27 2.86* 36 2.53* 7 .333 6 1.07 2 -1.57

3

58 -.022 11 -.67 15 -.2 13 .068 19 -.09 5 -.066 6 1.07 4 1.14

4

110 2.45* 24 2.65* 32 2.14* 22 1.86 32 1.91 6 .134 7 2.79* 2 -1.57

5

88 1.32 16 .61 27 1.45 19 1.27 26 .98 6 .134 5 -.655 4 1.14

6

103 2.09* 20 1.63 25 1.18 24 2.26* 34 2.22* 5 -.066 5 -.655 5 2.49*

7

69 .343 17 .86 20 .49 12 -.132 20 .06 6 .134 7 2.79* 4 1.14

8

107 2.29* 25 2.91* 28 1.59 26 2.66* 28 1.29 6 .134 6 1.07 4 1.14

9

86 1.22 25 2.91* 22 .77 23 2.06* 16 -.56 6 .134 6 1.07 3 -.216

10

109 2.4* 20 1.63 34 2.42* 25 2.46* 30 1.60 6 .134 5 .256 3 -.216


Appendix U: Individual Participant Scores on the BIS-11 and CPS and Significance Levels – Study Three

*significant at p<.05 (two tailed) a male case studies compared to Male Offenders M=24, SD=7.06 (n=412); female case study compared to Female Offenders M=23.15, SD=6.42 (n=311) (Carlson, 1982) b male case studies compared to Male Offenders M=28.95, SD=8.3 (n=412); female case study compared to Female Offenders M=30.44, SD=7.83 (n=311) (Carlson, 1982) c male case studies compared to Male Offenders M=36.3, SD=9.88 (n=412); female case study compared to Female Offenders M=32.4, SD=9.15 (n=311) (Carlson, 1982) d male case studies compared to Male Offenders M=20.55, SD=5.35 (n=412); female case study compared to Female Offenders M=20.51, SD=4.93 (n=311) (Carlson, 1982) e male case studies compared to Male Offenders M=3.82, SD=1.21 (n=412); female case study compared to Female Offenders M=3.55, SD=.81 (n=311) (Carlson, 1982) f male case studies compared to Male Inmates M=76.3, SD=11.86; female case study compared to Female General Psychiatric M=72.78, SD=13.43 ( Patton,Stanford & Barratt, 1995) g male and female case studies compared to the M and SD of the subscales outlined below (n=245; 108 males, 137 females) (Miller, Joseph & Tudway, 2004): BIS Motor Impulsiveness (MI) M=22.4 SD=4.46 BIS Non-Planning Impulsiveness (NPI) M=24.23 SD=4.99 BIS Cognitive Impulsiveness (CI) M=16.23 SD=3.3

Case Number

CAa Score

Z Score

TDb Score

Z Score

ATc Score

Z Score

SDd Score

Z Score

VALe

Score Z

Score BISf Total Score

Z Score

MIg Score

Z Score

NPIg Score

Z Score

CIg Score

Z Score

1

18 -.85 25 -.47 22 -1.45 13 -1.41 4 .15 87 .90 29 1.48 35 2.16* 23 1.96*

2

38 1.98* 41 1.46 56 1.99* 24 .65 5 .98 70 -.53 25 .58 24 -.05 21 1.36

3

27 .425 34 .62 42 .58 16 -.85 6 1.80 63 -1.12 20 -.54 23 -.25 20 1.05

4

33 1.27 46 2.06* 48 1.18 24 .65 7 2.63* 72 -.36 26 .81 22 -.45 24 2.26*

5

24 0 42 1.58 49 1.29 20 -.103 3 -.68 66 -.87 18 -.99 30 1.16 18 .45

6

30 .85 36 .86 43 .68 26 1.02 3 -.68 81 .39 24 .36 34 1.96* 23 1.96*

7

23 -.142 35 .74 41 .48 24 .65 4 .15 81 .39 26 .81 35 2.16* 20 1.05

8

11 -1.84 45 1.94 46 .98 28 1.39 3 -.68 60 -1.37 24 .36 22 -.45 14 -.77

9

13 -1.56 37 .98 49 1.29 28 1.39 3 -.68 75 -.11 27 1.03 26 .36 22 1.66

10

24 .132 38 .97 40 .83 18 -.51 3 -6.79 72 -.06 26 .81 25 .15 21 1.36


Appendix V:

Individual Participant Case Studies – Study Three

Case One – CS1 Whilst driving home after a long, hot day at work, CS1 recalls travelling on the highway. He had moved into the right-hand lane to overtake a group of slower vehicles when he drove up behind a female driver travelling in the right-hand lane, at approximately 85-90km/h in a 100km zone. CS1 reported that he became so angry with her for blocking his progress that he accelerated and “tapped” or “nudged” the rear of her vehicle. According to CS1, the woman appeared shocked and quickly pulled over into the left-hand lane. The incident was not brought to the attention of authorities. CS1 is 47 years of age and currently undergoing counselling for assaulting his defacto partner. He has been charged with ‘common assault’. He states that this is the first time in his life he has lashed out physically at a woman. There is no reported history of violence associated with his previous relationship to his wife of more than 25 years. His wife died a number of years ago, which when discussed appeared to cause him some emotional discomfort. On presentation, CS1 presents as well-dressed and well-spoken. CS1 is quite successful within the construction industry and earns over $70,000 per year. There is no reported history of dysfunction within his family of origin. Despite this, he mentioned that as an adult he has been involved in a number of fights. At school, he did not experience any difficulties with his education and never got into trouble. He appears to have associated with a positive peer group. He successfully completed Year 12. Over the last three years, CS1 has been involved in one road accident and been booked for speeding once. He owns a four-wheel drive, which he drives most often on highways/open road in heavy traffic. CS1 has been driving for over 20 years. He covers considerable distances for work purposes, driving approximately 16–20 hours per week. He did not report drink or drug driving in the last three years and further reported that it would be ‘not at all likely’ that he would do so. CS1’s scores on the total AQ (z=-.634), verbal aggression (z=-1.44), physical aggression (z=.63), angry aggression (z=.068) and hostile aggression (z=-1.79) subscales were not significantly different (p>.05) from the mean response for the previously identified hostile aggressive drivers*. Further, his scores on the SPSI-R subscales, NPO (z=.066, p>.05), ICS (z=1.07, p>.05) and RPS (z=1.216, p>.05) did not significantly differ from the hostile aggressive driver group*. These results suggest that CS1’s trait aggression and social problem solving scores are consistent with those drivers previously identified as hostile aggressive.


CS1’s total score on the BIS-11 (z=.90, p>.05) did not significantly differ from the previously published mean for male inmates (Patton, Stanford & Barratt, 1995)*. However, his scores on non-planning-impulsivity (z=2.16, p<.05) and attentional-impulsivity (z=1.96, p<.05) were significantly higher than the mean published for a general population (n=245) (Miller, Joseph & Tudway, 2004)*. He did not score significantly differently from this group on motor-impulsivity (z=1.48, p>.05)*. Interestingly, CS1’s scores on the CPS subscales did not differ significantly from the previously published mean for an incarcerated sample (n=412) (Carlson, 1982): CA (z=-.85, p>.05); TD (z=-.47, p>.05); AT (z=-1.45, p>.05); SD (z=-1.41, p>.05); and, VAL (z=.15, p>.05)*. When CS1’s total score for each subscale were plotted, the profile best fit the classification of: Type 13 – ‘self-centred’. See Appendix R for a brief description of type.


Case Two – CS2 Driving in a built up area, CS2 says the vehicle travelling beside him changed lanes suddenly, cutting him off. CS2 responded to this by gesticulating at the driver. In turn, profanities were exchanged. The other driver indicated for CS2 to pull over. Both drivers stopped and got out of their vehicles. They approached each other. Before the other driver was able to speak, CS2 punched him once. The other driver went down and did not get up. CS2 returned to his vehicle and drove off. He later realised that he had broken his knuckle when he struck the other driver. CS2 heard nothing more about the incident. CS2 is 39 years of age and has recently separated from his partner. He was born in New Zealand, moving to Australia in his early teens. He works in the construction industry and earns approximately $45,000 per year. He is currently attending counselling re his recent separation and associated anger issues. He is also taking medication for depression. CS2 outlined a troubled childhood during the interview. He described his childhood home as a “combat zone”. His father regularly physically and verbally abused him. Further, he had a detached relationship with his alcoholic mother. However, he enjoyed a close, fatherly relationship with his grandfather. As a consequence of his troubled home life, he repeatedly ran away from home and was eventually placed in a boys’ home. During his childhood, CS2’s peer group often came to the attention of the police. He also reports having caused considerable trouble at school. He left school in Year 10. CS2’s involvement with negative peer groups continued into his early adulthood. He states that he was involved in ‘gangs’ in New Zealand and after coming to Australia. Whilst involved in these groups, CS2 says he was involved in multiple fights. CS2 openly admits to being a heavy drinker, even though he claims to have been “dry” for the past six weeks. He also admits to being involved in many fights in the “pub scene”. He indicated that it would be ‘extremely likely’ that he would drink and drive. He also indicated it would be ‘moderately likely’ that he would drive under the influence of drugs. As a self-confessed car enthusiast, CS2 drives a medium sized vehicle most frequently. He drives for approximately 11–15 hours per week on highways/open road in medium density traffic. In the past three years, CS2 has been involved in two road crashes. He has also been fined for driving without a valid licence. Prior to this period, he has been charged for drink- driving on three occasions. He has been advised that next time he will receive a jail sentence and lose his licence for life. He has also been previously charged with ‘dangerous use of a motor vehicle’, ‘driving uninsured’, ‘failing to stop during a police chase’, ‘hooning’, ‘driving with his arm out the window’, ‘failure to wear a seat belt’ and ‘excessive noise’ (caused by his muffler modifications). In the off-road context, CS2 has been charged with ‘breaking and entering’, ‘assault’ and ‘vandalism’.


During the course of the interview, CS2 repeatedly demonstrated difficulty identifying and expressing his emotions. He also showed signs of dissociation. Specifically, he described an incident where his ex-partner had stabbed him with a kitchen fork, to which he calmly responded, “what are you doing?”. He stated that it did not hurt. Additionally, he did not realise that he had injured himself during the course of the road altercation until some hours later. Additionally, when asked his thoughts and feelings associated with the above on-road incident, he was unable to identify the emotions he experienced. When asked how he felt as he approached the other driver, he stated that his only thought was to “get him before he gets me”. He also commented that the behaviour he adopted during the incident was “normal” to him. CS2 scored significantly higher on total AQ (z=3.17, p<.05), verbal aggression (z=2.69, p<.05), physical aggression (z=2.91, p<.05), angry aggression (z=2.86, p<.05) and hostile aggression (z=2.53, p<.05) than the previously identified hostile aggressive driver group*. These results would suggest that CS2 has considerably high levels of trait aggression. Considering his developmental history, this result is not that surprising. CS2’s scores on the SPSI-R subscales did not significantly differ from those reported by the hostile aggressive driver group*: NPO (z=-.066, p>.05); ICS (z=1.07, p>.05); and RPS (z=-.216, p>.05). The results suggest that his problem-solving style is consistent with other hostile aggressive drivers. CS2’s total score on the BIS-11 was not significantly different from the comparison mean for an inmate group (z=.90, p>.05) *. However, nor were his scores on the individual subscales different from the general population*: motor-impulsivity (z=1.48, p>.05); non-planning impulsivity (z=-.05, p>.05); and attentional-impulsivity (z=1.36, p>.05). Consequently, it appears that CS2’s aggression appears to be emotionally and trait based, rather than stemming from impulsivity. On two of the CPS subscales, CS2 scored significantly higher than mean of the comparison group, i.e. incarcerated individuals *: CA (z=1.98, p<.05) and AT (z=1.99, p<.05). This would suggest that CS2 experiences considerable difficulty with chemical abuse, namely alcohol, and that he has persistent anti-social tendencies. CS2’s total scores for each subscale were plotted and the resultant profile best fit the classification of: Type 5 – ‘markedly anti-social’. See Appendix R for a brief description of type.


Case Three – CS3 Driving on a busy, dual carriage road, CS3 was cut off by a driver. He responded by beeping his horn and the driver, in turn, gave him “the finger”. Further down the road, the other driver repeatedly sped up attempting to cut CS3 off. Stopped by a red light at the next intersection, CS3 got out of his vehicle and approached the driver. At this point, he states, he was “ready for action” The other driver wound up his window and CS3 began to bash on the window. The other driver proceeded to drive through a red light. The incident was not reported. CS3 is a 55-year-old divorcee. Although he is currently unemployed due to a disability, he participates in volunteer community services. In the past CS3 attended counselling for an accident he was involved in. However, he is not currently in counselling. Whilst growing up, CS3 recalls that his parents were constantly verbally and physically abusive toward one another. Both parents were alcoholics. Occasionally, he would become involved in the physical abuse in his attempt to protect his mother. CS3 recalls having caused a moderate amount of trouble at school. However, it should be noted that he spent the minimum amount of time at school, leaving after primary school. As a young person, several of his friends attracted the attention of the police. He also says that as a young adult he was involved in many “bar fights” and one “gang fight”. CS3 drives a small vehicle for approximately 11–15 hours per week. He most frequently drives on city/town roads in medium density traffic. In the last three years, CS3 has been fined twice for speeding. Prior to this period, he has received several speeding fines, charged with “running a red light” and “overtaking on double lines”. Although, he had admits to having been a heavy drinker in the past, he now drinks significantly less. He states that these days it would be ‘not at all likely’ he would drink or drug drive. At the time of the above incident, CS3 states he was under considerable stress due to his separation from his wife of 29 years. When discussing the above incident he stated that, in general, he was “not a patient driver”. CS3’s scores on the AQ did not differ significantly from the previously identified hostile aggressive driver group*: total AQ (z=-.022, p>.05); verbal aggression (z=-.67, p>.05); physical aggression (z=-.2, p>.05); angry aggression (z=.068, p>.05); and hostile aggression (z=-.09, p>.05). Nor, did his scores on the SPSI-R subscales differ from this group: NPO (z=-.066, p>.05); ICS (z=1.07, p>.05); and RPS (z=1.14, p>.05). As such, it appears that CS3 has similar trait aggression and social problem solving skills to other hostile aggressive drivers.


Further, his total BIS-11 score was not significantly different from the mean for an inmate population * (z=-1.12, p>.05). His individual subscale scores also failed to be significantly different from the general population*: motor-impulsivity (z=-.54, p>.05); non-planning impulsivity (z=-.25, p>.05); and attentional-impulsivity (z=1.05, p>.05). Consequently, CS3 appears to have similar levels of impulsivity to the general population. Therefore, his driving anger appears to be sourced by his trait aggression. Such a suggestion is consistent with his developmental history. CS3’s scores on the CPS subscales, were not significantly different from the means for an inmate population*: CA (z=.425, p>.05); TD (z=.62, p>.05); AT (z=.58, p>.05); SD (z=-.85, p>.05); and VAL (z=1.8, p>.05). CS3’s total scores for each subscale were plotted and the resultant profile best fit the classification of: Type 5 – ‘markedly anti-social’. See Appendix R for a brief description of type.


Case Four - CS4 CS4 was driving along a main road in a built-up area when he began to slow down for a red light. A driver travelling in the parallel lane had realised that he was in the wrong lane and reportedly “cut him off’, coming to a stop in front of him. CS4 became so angry with the driver that he yelled abuse. The other driver responded with a hand gesture, which seemed to exacerbate the situation. As a result, CS4 left the vehicle running and approached the other driver’s vehicle on foot. A series of brief profanities were exchanged through the driver-side window. As a result, CS4 punched the driver through the open window and yelled at the driver to get out of his vehicle. The other driver wound up the window and drove off quickly, through a red light. The incident was not brought to the attention of authorities. CS4 is 30 years of age and currently living in a defacto relationship. He is currently undergoing anger-management training as a result of relationship difficulties. CS4 is currently unemployed and receives a social security benefit. CS4’s background is complex. His parents were strict and quite religious. CS4 reports that when he was young he was sexually abused by his Sunday School teacher. CS4 says that when he tried to tell his parents about it, they refused to believe him. Subsequently, CS4’s life became more complicated. He caused considerable trouble at school and completed Year 10 with minimal grades. Shortly after leaving school, he became involved in a ‘skinhead’ (neo-nazi) gang. Further, his best friend, to whom he was very close, died in a car accident at 16 years of age. At the age of 17, CS4 was imprisoned for 11 years for the attempted murder of his parents. In addition to being charged with two counts of attempted murder, he was charged with two counts of arson. CS4 continued to have difficulties in prison. He was reportedly raped whilst serving his sentence. Whilst in prison, he received counselling for the childhood abuse and for the rape. He states that he was also diagnosed with Dissociative Identity Disorder (DID). Due to his period of incarceration, CS4’s driving experience has been limited i.e. only 3 years. He owns a large vehicle which he drives approximately 10–15 hours per week. He most frequently drives on city/town roads in medium density traffic. In the last two years since his release, he has faced one charge of unlicensed driving and been involved in one road crash. When asked how likely he would be to drink and drive, CS4 did not rule out the possibility. It should be noted that he had been drinking prior to the aggressive driving incident cited above. He stated that he was “half way through his third stubby”. He reported that it would be ‘not at all likely’ that he would drive under the influence of drugs. CS4’s score on the total AQ, verbal aggression subscale and physical aggression subscale were significantly higher than the mean of the hostile aggressive driver group*: z=2.45, p<.05; z=2.65, p<.05; and z=2.14, p<.05 respectively. However, his scores on the angry aggression and hostile aggression subscales were not significantly different from the hostile


driver group: z=1.86, p>.05 and z=1.91, p>.05. Also, his scores on the NPO and RPS subscales of the SPSI-R were not significantly different from hostile aggressive driver group: (z=.134, p>.05) and (z=-1.57, p>.05). However, he scored significantly higher than this group on ICS (z=2.79, p<.05). These results would suggest that CS4 has high levels of trait aggression, accompanied by an impulsive/careless style of problem solving. Consequently, in the face of direct or perceived provocation, CS4 may be predisposed to respond in an impulsive manner. This suggestion is consistent with his score on attentional-impulsivity of the BIS-11. CS4’s score on attentional-impulsivity was significantly higher than the mean for the general population* (z=2.26, p<.05). His motor impulsivity and non-planning impulsivity scores were not significantly different from this group: z=.81, p>.05 and z=-.45, p>.05. CS4’s scores on the CA, AT, and SD subscales of the CPS did not significantly differ from the mean for an incarcerated population*: CA (z=1.27, p>.05); AT (z=1.18, p>.05); and SD (z=.65, p>.05). However, his scores on TD and VAL score did differ significantly*: z=2.06, p<.05; and z=2.63, p<.05. These results would suggest that CS4 has similar chemical abuse, anti-social tendencies and self-deprecation levels as other incarcerated individuals. However, he has significantly higher levels of thought disturbance, consistent with the reported diagnosis of DID. His inflated VAL score would suggest that he failed to maintain an appropriate mind-set during the administration of the CPS. As Carlson (1982) would suggest, perhaps CS4 became careless, facetious whilst answering the questions. Alternatively, he did not understand the questions (Carlson, 1982). Indeed, the latter may be a more appropriate evaluation of the situation, as a number of questions needed to be restated and at times explained further, in order for him to respond. When CS4’s total score for each subscale were plotted, the profile best fit the classification of: Type 5 – ‘markedly anti-social’. See Appendix R for a brief description of type.


Case Five – CS5 Driving in the right-hand lane of a dual carriage road, CS5 noticed a car speeding towards him in his rear view mirror. The vehicle then continued to follow him very closely. The vehicle eventually passed and turned-off into a side road soon after. At this point, CS5 decided to follow the vehicle. The side road had multiple traffic slowing islands, causing the driver of the other vehicle to drive slowly. Having noticed that CS5 was following him, the driver stopped at the second island and got out of his vehicle. CS5 stopped his vehicle, grabbing his ‘club lock’. Profanities were exchanged and CS5 proceeded to use the ‘club lock’ on the other driver’s bonnet, windscreen, side door and side mirror. The other driver, quickly jumped into his vehicle and sped off. No charges were laid as a result of this incident. CS5 is a 44 year old, married, security guard. He earns approximately $45,000 per year. During the course of his life, CS5 has been actively involved in many different lines of work (e.g. military service, construction and volunteer fire fighters). In the past CS5 has been counselled for severe depression. He is not currently in counselling. CS5 had a difficult childhood. His mother and father were alcoholics and he frequently observed violence in the family home. Further, his father physically abused him. CS5 was once hospitalised as a result of the abuse. He became involved with a negative peer group. Some of his friends were picked up by the police and he became involved in a ‘gang’ which was frequently involved in fights. He stated that he was frequently in trouble at school for his conduct and, during that time, had “no respect for authority or the law”. He frequently ‘skipped’ school. Despite this, he completed Year 10. During the interview, CS5 stated, that as a young person he “was always right”. He also claimed to be “emotionally reactive his whole life”. CS5 currently drives a medium sized vehicle which he drives for approximately 11–15 hours per week. He drives most often on city/town roads in medium density traffic. In the last three years, CS5 has not been involved in any road crashes. During this same period he has been booked once for speeding. Asked if how likely it would be that he would drink or drug drive, he did not rule out the possibility of drink-driving. CS5 has had many driving and other charges during his life. As an adult, he has been charged with ‘unlicensed driving’, ‘drink-driving’, multiple counts of speeding, ‘unlawful right hand turns’ and ‘passing a vehicle on the inside’. Off-road charges include ‘breaking and entering’, multiple counts of ‘theft’, ‘assault’ and ‘seriously affronting’. He claims that all of these charges were incurred between 14 and 17 years of age. CS5’s scores on the total AQ and its subscales did not differ significantly from the hostile aggressive driver group*: total AQ, z=1.32, p>.05; verbal aggression, z=.61, p>.05; physical aggression, z=1.45, p>.05; angry aggression, z=1.27, p>.05; and hostile aggression, z=.98, p>.05. His scores on the SPSI-R subscales did not significantly differ from the hostile aggressive group: NPO, z=.134, p>.05; ICS, z=-.65, p>.05; and RPS,


z=1.14, p>.05. Therefore, his trait aggression levels and social problem-solving style are consistent with other hostile aggressive drivers. His BIS-11 total score was not significantly different from an incarcerated comparison group*, z=-.87, p>.05. Also, his scores on the BIS-11 subscales were not significantly different from the general population*: motor-impulsivity (z=-.99, p>.05), non-planning impulsivity (z=1.16, p>.05) and attentional impulsivity (z=.45, p>.05). Consequently, CS5’s aggression appears to be sourced from trait aggression and less by impulsivity. Examination of CS5’s scores on the CPS subscales, revealed no significant difference when compared to the inmate means for the subscales*: CA,(z=0, p>.05); TD (z=1.58, p>.05); AT (z=1.29, p>.05); SD, (z=-1.03, p>.05); and VAL, (z=-.68, p>.05). When plotted, CS5’s profile best fit the classification of: Type 5 – ‘markedly anti-social’. Although, it should be noted that his score for chemical abuse (x=24) fell slightly short of the range of scores normally associated with this type (i.e. 27 to 38). See Appendix R for a brief description of type.


Case Six – CS6 CS6 was travelling down the left-hand lane of the highway at approximately 90km, when the driver of a utility truck appeared to come ‘out of nowhere’. CS6 reported that the other driver drove extremely close to the rear of his vehicle for the next kilometre. He also stated that as he was in the left-hand lane and the driver had adequate opportunity to overtake him. CS6 became extremely angry with the driver and decided to brake heavily, causing the other driver to collide with the rear of his vehicle at approximately 90km. Both remained on the road and continued driving for a short time. CS6 then pulled over and the driver of the other vehicle kept going. Consequently, CS6 got back into the vehicle and followed him. Eventually, the other driver pulled over to the side of the road and CS6 pulled over 50 metres behind him. Profanities were exchanged and the other driver climbed back into his vehicle and drove off. After recording the details of the vehicle, CS6 pursued him for some time before losing him. He then went straight to the police station and reported the incident for “insurance purposes”. CS6 is 29 years of age and married. He earns approximately $36,000 per year. Although not currently in counselling, CS6 has previously attended counselling for marital difficulties and job related stress. Whilst growing up CS6, his siblings and mother, were physically abused by his alcoholic father. He also reported that his father had essentially taken the family hostage one time. Consequently, he describes his childhood home as “disruptive”. He reported that he had caused trouble at school a number of times and most of his peers came to the attention of the police. Despite his difficult background, CS6 successfully completed a certificate level course at TAFE and has gained responsible positions e.g. Council parking officer. CS6 currently drives a small car. He reportedly drives most frequently on city/town road in heavy traffic for 6–10 hours per week. In the past three years, CS6 has been involved in three road crashes. He has not been charged with any traffic-related offences in the last three years. However, prior to this period he was charged on three separate occasions with speeding and red light running. CS6 has no history of other, off-road charges against him. Interestingly, CS6 reported that he would be moderately likely to drive under the influence of alcohol and/or drugs. It should be noted that CS6 had been drinking at the time of the above incident. CS6s scores on the total AQ, angry aggression and hostile aggression subscales were found to be significantly higher than the hostile aggressive driver group*: total AQ, (z=2.09, p<.05); angry aggression (z=2.26, p<.05); and hostile aggression (z=2.22, p<.05). He also scored significantly higher on the RPS subscale of the SPSI-R, than this group (z=2.49, p<.05). Thus these results would suggest that CS6 has considerably high levels of trait aggression, particularly angry and hostile aggression. Despite this, he has a higher degree of rational problem solving than most hostile aggressive drivers.


CS6’s total BIS-11 score did not differ significantly from the mean of the comparison group* (i.e. an inmate population) (z=.39, p>.05). Further, he scored significantly higher than the general population* on non-planning impulsivity (z=.65, p>.05) and attentional impulsivity (z=.65, p>.05). Therefore, these results suggest that CS6 has some difficulty with impulsivity. His CPS subscale scores were not significantly different from the mean for the incarcerated group*: CA (z=.85, p>.05); TD (z=.86, p>.05); AT (z=.68, p>.05); SD (z=1.02, p>.05); and VAL (z=-.68, p>.05). Profiling of CS6’s total score for each subscale resulted in a profile that best fit the classification of: Type 16 – ‘negative/explosive’. See Appendix R for a brief description of type. However, it should be noted that his score on anti-social tendencies (x=43) was outside of the range for this type (i.e. 46 and above).


Case Seven – CS7 CS7 was driving a truck through a heavily built up area when he noticed a sedan that was speeding up behind him and cutting in and out of traffic. The vehicle came alongside of him and indicated to cut in front of him. However, a set of lights turned red and the other driver was forced to slow down and pull in behind his truck. At this point, CS7 was so annoyed that he got out of his vehicle and walked back to the other driver’s vehicle. Profanities were exchanged whilst the other driver also got out of his vehicle. CS7 struck the other driver and a fist-fight ensued. Several other drivers who witnessed the incident got out of their vehicles and pulled them apart. Shortly afterwards, several police cars arrived. No charges were laid. CS7 is a 46 year old, professional truck driver. He earns over $70,000 per year. CS7 is currently attending counselling after recently separating from his wife of 23 years. In the past, CS7 has attended counselling for an attempted suicide. CS7 was born and raised for much of his childhood in New Zealand. He is of Maori descent. As a youth, CS7 has a difficult relationship with his mother. As the disciplinarian in the family, CS7’s mother physically abused the children. CS7’s relationship with his father was estranged. CS7 successfully completed Year 10. He also stated that he got into a little trouble at school. During the interview, it was noted that CS7 had also suffered great loss during his early adulthood. His mother, sister and a close friend died within one year of each other. Due to his profession as a truck driver, CS7 drives on all types of roads, in varying levels of traffic density. CS7 drives more than 20 hours per week. In the past three years, he has not been involved in any road accidents. During this same period, he has been booked twice for speeding. Although, CS7 has lost count of the number of speeding fines he has received over the years. Due to his profession as a truck driver, CS7 stated that it would be ‘not at all likely’ he would ever drink or drug drive. However, CS7 does drink socially. CS7’s scores on the AQ were not significantly different from the previously identified hostile aggressive driver group*: total AQ, z=.343, p>.05; verbal aggression, z=.86, p>.05; physical aggression, z=.49, p>.05; angry aggression, z=-.132, p>.05; and hostile aggression, z=.06, p>.05. His ICS score was also significantly higher than the mean for the hostile aggressive diver group (z=2.79, p<.05). Therefore, these results suggest that CS7 has reasonably high levels of trait aggression and high levels of impulsive/careless problem solving style. CS7’s scores on the CPS subscales did not differ significantly from the mean of the comparison group of inmates*: CA (z=.-.14, p>.05); TD (z=.74, p>.05); AT (z=.48, p>.05); SD (z=.65, p>.05); and VAL (z=.15, p>.05). Plotting of the subscale total scores resulted in a profile that best fit the classification of: Type 5 – ‘markedly antisocial’. See Appendix R for a brief description of type. Although, it should be noted that his chemical abuse score (x=23) was outside of the range for this type (i.e. 27 to 38). However, his lower score would be consistent with the need to maintain sobriety for the purpose of driving professionally.


Case Eight – CS8 CS8 and his partner were driving along a main road with businesses either side. A four wheel drive, coming off private property, pulled out in front of his vehicle with little room to spare. CS8 states that he had to “jump on his brakes” to avoid hitting him. Further up the road, he and the other driver were stopped at a red light. At this point, CS8 got out of his vehicle and approached the driver of the four wheel drive. He states that he leaned on the driver side mirror of the vehicle and profanities were exchanged for a while. The other driver shook his fist at him, and in response CS8 started to “wriggle his side mirror from side to side”. The other driver opened his driver-side door in order to get out. At this time, CS8, forced the door shut, jamming the driver’s hand in the door. The lights turned green and the other driver drove off. The other driver reported the incident to the police and CS8 has been charged with ‘wilful damage’ of the four wheel drive. The damage is valued at $1000. The court case is pending. CS8 is 50 years of age and currently living in a defacto relationship. He is currently unemployed but is a chef by trade. CS8 is currently attending counselling for depression and financial problems. He reported that in the past he has attended counselling for depression and fatigue. As a youth, CS8 reported being repeatedly physically abused by his alcoholic father. He reported having caused considerable trouble at school and association with a less than positive peer group. Some of his peers came to the attention of the police for reasons unspecified, and two of his close friends committed suicide in their teens. He successfully completed Year 10. CS8 reported having been a heavy drinker in the past and maintains that he no longer drinks. It was noted that CS8 was slightly evasive with his responses to questions relating to alcohol consumption or drink-driving. CS8 drives a medium sized vehicle and reportedly drives most frequently on city/town road in medium density traffic. He drives approximately 16–20 hours per week. CS8 reported that he had not been involved in any road crashes, or received any speeding or drink- driving fines in the past three years. However, during this same period, he had been fined with ‘driving an unregistered vehicle’. He reported that it would be ‘not at all likely’ that he would drink or drug drive. Interestingly, prior to this period he had been fined for ‘drink-driving’ and ‘drink-driving whilst disqualified’. As a youth he was also charged with ‘theft of a motor vehicle’ and more recently he was charged with ‘wilful damage to property’ as outlined in the case above. At the time of the aggressive driving incident outlined above, CS8 states that he had been under considerable stress and strain associated with his partner’s young daughter. Further, his partner was travelling with him at the time and was quite “hysterical” about her daughter’s situation.


CS8’s scores on total AQ, verbal aggression and angry aggression were significantly higher than the means for the hostile aggressive driver group*: total AQ (z=2.29, p<.05); verbal aggression (z=2.91, p<.05); and angry aggression (z=2.66, p<.05). His SPSI-R subscale (NPO, ICS and RPS) scores did not differ significantly from the hostile aggressive group*. Therefore, the results suggest CS8 has considerably high levels of trait aggression, particularly verbal and angry aggression. His total BIS-11 score was not significantly different from the mean for an incarcerated group* (z=-1.37, p>.05). Also, his BIS-11 subscale scores were not significantly different from the general population*: motor impulsivity (z=.36, p>.05); non-planning impulsivity (z=-.45, p>.05); and attentional impulsivity (z=-.77, p>.05). On the CPS subscales CS8’s scores did not differ significantly from the mean of the inmate group*: CA (z=-1.84, p>.05); TD (z=1.94, p>.05); AT (z=.98, p>.05); SD (z=1.39, p>.05); and VAL (z=-.68, p>.05). Profiling of CS8’s total score for each subscale resulted in a profile that best fit the classification of: Type 16 – ‘negative/explosive’. See Appendix R for a brief description of type. However, it should be noted that his score on chemical abuse (x=11) is considerably below the range for this type (i.e. 26-37). However, he has openly stated that he does not indulge in alcohol as much as he used to.


Case Nine – CS9 CS9 was driving to the vet with his dog, when a car reversed out off commercial premises in front of him. He was forced to brake heavily and flashed his lights at the other driver. The other driver responded with “the finger”. At the next set of lights the other driver turned off. At this point, CS9 decided to follow him. The other driver lived in the street and pulled into his driveway. CS9 pulled up in front of his home. Both drivers got out of their vehicles and started exchanging profanities. CS9 claims that the other driver tapped him behind the ear first. In response, CS9 hit the other driver. The other driver went over the fence and struck his head on the concrete. CS9 returned to his vehicle and drove off. CS9 was later advised that an ambulance was called to the address. The other driver was hospitalised for approximately 24 hours. Witnesses provided the authorities with CS9’s registration details. When he became aware that the police were looking for him, he approached them of his own volition. He was subsequently charged with “actual bodily harm”. The Court instructed that he complete 150 hours community service for this offence and attend counselling for his anger. CS9 is 52 years old and living in a defacto relationship. He currently earns approximately $15,000 per year. CS9 is currently attending court order counselling as outlined above. He states that his family doctor has diagnosed him with “late onset – ADHD” and depression. He is currently taking medication for both disorders. Whilst growing up, CS9 enjoyed a relatively close relationship with his mother and father. He describes his, recently deceased father as a ‘chronic hypochondriac’. As a teen, he says he was involved in a number of fights. During his adulthood he also states that he was involved in “pub fights”. He readily admits to having been a heavy drinker, prior to his diagnosis with cancer. As a result of treatment for the cancer, CS9 claims he suffered severe damage to his kidneys. Hence, he does not drink anymore. At one time, he claims he was ‘raped’ by a male, whilst he was extremely drunk. At school he caused considerable trouble and he describes the peer group of his youth as “either dead or in jail”. Despite this he completed Year 12 and went on to complete a TAFE certificate. CS9 currently drives a medium sized car, 6–10 hours per week. He most often drives on highways or open road in medium density traffic. In the past three years, CS9 has not been fined for speeding, drink-driving or unlicensed driving. However, he has been charged with ‘actual bodily harm’ as outlined in the above aggressive driving incident. Prior to this period, he has incurred an unspecified number of speeding fines, been charged three times for ‘drink-driving’ and once for ‘driving whilst disqualified’. As an adolescent, he was charged with ‘criminal damage’, ‘assault’ and ‘shoplifting’. At the time of the above incident, CS9 says that he was under considerable stress, as he was in the middle of moving house. He also claims that his behaviour may have been due to the


fact that he had not taken his medication over the preceding 36 hours. In addition, he had consumed a bottle of wine the evening beforehand. He described that he was feeling quite “seedy” at the time. During the interview, CS9 was observed to have difficulty recalling the thoughts he had whilst the incident was in play. When asked if he felt guilty or remorseful about his behaviour he stated “ no, I should have killed him”. Also, he stated that he regretted being “caught” and that next time he will “cover his number plate with a hankie” before he takes such action. Although CS9’s total AQ score, physical aggression and hostile aggression scores did not differ significantly from the previously identified hostile aggressive driver group*, his verbal aggression and angry aggression subscale scores did differ significantly (z=2.91, p<.05 and z=2.06, p<.05 respectively). On both scales scored significantly higher than the mean for the hostile group. His scores on the SPSI-R subscales were not significantly different from the means for the hostile group: NPO (z=.14, p>.05); ICS (z=1.07, p>.05); and RPS (z=-.216, p>.05). In general, these results suggest that CS9’s trait aggression levels are quite high, particularly for verbal and angry aggression. CS9’s total BIS-11 score did not differ significantly from the mean for the comparison group of inmates* (z=-.11, p>.05). Comparison of his BIS-11 subscale scores with the means for a general population* did not yield a significant difference: motor-impulsivity (z=1.03, p>.05); non-planning impulsivity (z=.36, p>.05); and, attentional-impulsivity (z=1.66, p>.05). These latter results were a little surprising in light of CS9’s reported diagnosis of ADHD. However, perhaps the administration of medication has confounded these particular results. All of CS9’s CPS subscale scores did not significantly differ from the mean for the inmate comparison group*: CA (z=-1.56, p>.05); TD (z=.98, p>.05); AT (z=1.29, p>.05); SD (z=1.39, p>.05); and VAL (z=-.68, p>.05). CS9’s total score for each of these subscales were plotted, and the resultant profile best fit the classification of: Type 5 – ‘markedly anti-social’. See Appendix R for a brief description of type. It should be noted that CS9’s chemical abuse score (x=13) falls below the range for this subscale. However, he admits to having been a heavy drinker, but now he has a reduced capacity to do so due to kidney damage.


Case Ten – CS10 CS10 and three friends were returning from late-night shopping one evening, when a vehicle came up behind them with its lights on highbeam. She states that the vehicle was also driving fairly close to her bumper and appeared to be following her. In response, CS10 repeatedly braked. She states that the vehicle stopped following them, at which time she decided to pursue them. She followed the vehicle until they were both stopped at a red light. At this point, CS10 took a large, metal torch from her vehicle and approached the vehicle on foot. The female driver of the other vehicle wound up her window as CS10 proceeded to verbally abuse her and ask her why she had been following them. CS10 became so frustrated and angry that she smashed the side mirror off the vehicle with her torch. When CS10 had returned to her car, the woman got out of her vehicle and recorded her number plate. CS10 found out later that one of the backseat passengers in her vehicle had flicked a lit cigarette out the window onto the woman’s vehicle. CS10 speculated that perhaps that is why she was driving closely. CS10 is 24 years of age and currently living in a defacto relationship. She is currently employed and earns approximately $35,000 per year. Although CS10 is not currently in counselling, she has had counselling in the past and has been diagnosed with Bipolar Disorder for which she is currently taking medication. CS10 states that she often feels “very angry” and “depressed”. During the interview, she appeared to be rather heavily medicated, demonstrating slow speech and difficulty recalling her thoughts and feelings concerning major life events. In addition, she reported having difficulty removing the above incident from her thoughts. She stated that she kept going over it in her mind and that it ruined the rest of her day. CS10 had a difficult childhood. Her mother and father were both alcoholics and she frequently witnessed physical violence between them. She, also, was physically abused by her father. Although CS10 completed Year 12, she reported that she was repeatedly in trouble at school. She also reported that some of her peers were picked up by police. CS10 currently drives a medium sized vehicle, which she most frequently drives on city/town road in medium density traffic. She drives approximately 11–15 hours per week. In the past three years, CS10 has been fined once for speeding and has not been involved in any road crashes. However, prior to this period, she reports that she has been charged twice for drink-driving and once for speeding. When asked about any non-driving related offences, she reported that she had been previously charged with ‘assault’. CS10 openly stated that she was a heavy drinker. However, she recently decided to abstain from alcohol because it was causing problems with her medication. Consequently, she


reported that it was ‘not at all likely’ that she would drive under the influence of alcohol or drugs. CS10’s total AQ score, physical aggression score and angry aggression score were significantly higher than the hostile aggressive driver group*: total AQ (z=2.4, p<.05); physical aggression (z=2.42, p<.05); and (z=2.46, p<.05). Her social problem solving subscale scores did not differ from the hostile group*: NPO (z=.134, p>.05); ICS (z=.256, p>.05); and RPS (z=-.216, p>.05). These results indicate that CS10 has relatively high trait aggression levels, particularly for physical aggression and angry aggression. The latter result is consistent with her persistent self-reported feelings of ‘anger’. Thus it appears that CS10’s on-road aggression is sourced from emotional and trait related aggression. Additionally, CS10’s total BIS-11 score did not significantly differ from the mean for a female, general psychiatric group* (z=-.06, p>.05). This result is consistent with her reported diagnosis with a clinical disorder (i.e. bipolar disorder). Surprisingly, her scores on the BIS-11 subscales differ significantly from a general population means*: motor-impulsivity (z=.81, p>.05); non-planning impulsivity (z=.15, p>.05); and, attentional-impulsivity (z=1.36, p>.05). CS10’s CPS subscale scores were not significantly different from the means for a sample of female inmates*: CA (z=.132, p>.05); TD (z=.97, p>.05); AT (z=.83, p>.05); SD (z=-.51, p>.05); and VAL (z=-6.79, p>.05). Profiling of CS10’s total score for each subscale resulted in a profile that best fit the classification of: Type 5 – ‘markedly antisocial’ (refer to Appendix R for a brief description of type). It is acknowledged that CS10’s score on the chemical abuse scale (x=24) is outside of the range normally present in this type (scores ranging from 27-38). However, her lower CA score is consistent with her recent decision to abstain from alcohol.

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The Psychosocial Factors Influencing Aggressive Driving ...Brien_Thesis.pdf · behaviour. Study One (n = 48) examined aggressive driving behaviour from the perspective of young drivers