Chapter 3: The Behavioral Genetics of Predatory Criminal Behavior John Paul Wright Kevin M. Beaver

Chapter 3: The Behavioral Genetics of Predatory Criminal

BehaviorJohn Paul Wright

Kevin M. Beaver

Overview

• The leading criminological theories social learning theory, strain theory, and self-control theory all require biological and genetic factors to be valid

• The media frequently reports startling results linking brain functioning to criminal behavior, or reports new linkages between specific genes and criminal traits

• This may be why “the biological sciences have made more progress in our understanding of criminal behavior in the last 10 years than sociology has made over the past 50 years” (Robinson, 2004:x)

Overview

• This chapter seeks to demystify the influence genes have on behavior and serves to introduce the reader to a “biosocial” understanding or predatory offending

• In particular we provide the reader a brief introduction on what is known about:

– Predatory offending, about the fundamentals of human genetics, about the methods used by behavioral genetics, and about how this information is used to understand predatory human behavior

The Roots of Predation

• Predation involves an intention to do harm to another, or at least a willingness to actively seek out and injure another person

• Even among criminals, predation in criminal conduct is unusual – only the most serious and habitual offenders are predatory

• This is not to say that predatory offenders are not also opportunists or that they do not commit crimes when under the influence

• The difference is that predatory offenders do not require or are not driven by these concerns – predatory offenders are the truly criminal


• Research findings on the development of serious criminal conduct have revealed 3 important findings:

1. An amazing wealth of data converge to show that the warning signs for serious predation are visible in infancy and childhood

1. Traits related to later criminal conduct are also visible in infancy and early childhood

2. Studies into the development of aggression have found that its onset occurs around the time when children gain mobility


• Physical aggression is a nearly universal human capacity, is “normal” early in life, but becomes more uncommon in children over time

• Perhaps not surprisingly, an early age of onset is one of the strongest predictors of future adult predatory offending

• Moreover, virtually every predatory offender has experienced an early age of onset

A Behavioral Genetic Understanding of Predatory Offending

• Traditional criminological theories remain silent – largely because these theories of crime locate the causes of misconduct in adolescence

• Criminologists would likely point to parental rearing environments as the putative source variation in young children’s behaviors

– But would they be correct?


• Behavioral genetics is the field of study that examines how much variance in any given trait or behavior is accounted for by genetic and environmental influences

• At the heart of the field is the estimation of genetic and environmental influences

• Behavioral geneticists also specify 2 types of environmental influences: – Shared environments– Non-shared environments


• Non-shared environments: are those unique experiences that make individuals more different than alike

• Shared environments: are thought to make people more alike

• Findings from hundreds of studies now show that virtually every human trait and characteristic is genetically influenced


• For certain characteristics – especially those associated with predatory offending – genetic influences dominate

• The behavioral genetic studies typically show that shared environments have little to no effect on their adult offspring

• The processes that link parenting practices to human development likely operate through biological mechanisms

A Brief Note on Human Genetics

• Human-beings inherent 22 pairs of chromosomes from each parent, plus 1 sex differentiating chromosome

• DNA is composed of 2 elongated sections bonded to chemical bases – the now familiar double-helix

• Genes, which are embedded in chromosomes, are merely stretches of DNA with a known arrangement of base pairs


• Mendelian theory tells us that we inherit 2 copies of each gene – 1 from the father and the other from the mother

• Genes play a significant role in serious, predatory behavior

• Even with multiple copies of some genes, they are not all turned on or off at one time


• The process whereby our genes are activated or turned off is called genetic imprinting

• Genes come in different varieties – differences in genes are called alleles

• Allelic variation occurs when mutations, genetic drift, culture or evolution alters a gene

• Genes with various alleles (a lee os) are referred to as polymorphic


• Understanding the role of genes in complex human phenotypes is made even more complicated by the fact that humans do not always follow Mendelian genetic principles

• Functional human genes appear to follow a pattern of incomplete dominance in their relationship to traits and behaviors

• Incomplete dominance refers to a situation where the effects of dominant and recessive alleles are blended and then expressed in a phenotype

How Do Genes Work to Influence Predation?

• Complex traits and behaviors are usually not produced by

single genes

• The term “genetic potentials” refers to genes creating

general behavioral tendencies, or propensities, that can

sometimes be contingent on the environment for their

activation

• Single gene influences are also typically rather small,

usually explaining less than 5% of the variance in any

complex behavior – such as violence


• In studying predatory offenders, there’s one overriding, consistent, and obvious fact – predatory offenders are universally male

• The male brain has 10% more area dedicated to aggression

• Males are generally more status oriented and ascribe to status hierarchies – which are also known as dominance hierarchies


• Dominance can be achieved through a variety of

methods, but the most efficient method employed

more frequently by males than females is violence

• Dominance fueled by testosterone may be why overt

physical aggression and predatory behavior in males

appears to fully materialize during adolescence

• The amygdale is the “seat of emotions and emotional

memory” – which is of particular interest to the study

of predatory criminal behavior


• The amygdale provides humans with the ability to match an event to a specific emotion and thereby gives us the ability to recall the experiences as well as the feelings associated with the experience

• Several studies show that empathy is absent in psychopaths and that its absence is due to problems associated with amygdale responses

• The last part of the brain to develop is the neocortex – or the “thinking part” – which is responsible for the human abilities of planning, delaying gratification, impulse control, and rational thought


• The cortex houses the “executive functions” of the brain – such as self-control and emotional regulation

• Numerous studies have shown that the cortex is critical to prosocial human behavior

• Certain individuals appear to lack self-control because of deficits in the ventrolateral prefrontal cortex – especially deficits in the left hemisphere


• This pattern of findings is particularly striking for males, whose brains are more at-risk for neurological insult and who have more problems with impulse control

• All sensory input is channeled 1st to the limbic system

• When strong emotions are encountered, the initial limbic impulse may be to act with violence, or to act aggressively

• The cortex may intervene to curtail or modify the initial limbic impulse – obviously, deficits in the cortex will allow those impulses to materialize in the form of behavior


• Those with the inefficient allele were thought to have excess

serotonin – which, theoretically, would increase impulsivity

• Individuals with inefficient allele showed substantial

reductions in brain volume in areas of the brain that control

attention and emotions

• Further evaluation found that the OFC was less active and

less connected to the amygdala in men with the inefficient

allele

– Recall that the OFC is deeply implicated in self-control and

emotional regulation


• The human genetics is related to predatory offending through 3 primary variables: sex, brain structure and functioning, and neurotransmission

• How the genotype codes for these biological factors plays a large role in the resulting expression of criminogenic traits

• Genotype is also influenced by environmental variables – such as the induction of neurotoxins and constant stress and anxiety

• It’s not clear that serious offenders would behave differently even if presented with entirely prosocial environmental stimuli

Criminality

• Genome may not influence behavior directly – that is,

genes do not cause behavior

• Instead, genes create the conditions for various

human traits to be expressed in terms of personality,

thinking patterns, and ultimately behavior

• The concentration of these traits within an individual

elevates the likelihood that he will engage in

predatory conduct for much of his life

Criminality• Predatory offenders often have problems with self-control

– in that they act impulsively and sometimes without

accurately assessing the immediate situation

• They tend to be narcissistic, thinking primarily of

themselves and their needs and wants, and they appear

unable to relate to the pain and anguish they cause

others

• They also tend to be below average in measures of IQ,

especially on measures of verbal IQ

Criminality

• They tend to view the world negatively, with open hostility

towards others, and they tend to act aggressively with

provocation

• Theirs is also a lifestyle of drug-use, partying, and general

irresponsibility

• Criminality, or the propensity to commit crime and other

destructive behaviors, manifests itself from the

confluences of these traits

Criminality

• A behavioral genetic understanding of these traits highlights

2 inter-related points:

1. All of these traits have high levels of heritability,

especially IQ, impulsiveness, and self-control

2. Many individuals suffer from relatively low levels of self-

control, have high levels of impulsivity, and are non-

empathetic but are not criminal

Conclusions

• Behavioral genetics have yet to fully penetrate

criminology

– One reason for this is that many criminologists fear

that recognizing genetic influences will leave them

with nothing left to study

• Understanding predation from a behavioral genetic

viewpoint does not obviate the importance of

environmental factors

Conclusions

• A behavioral genetic viewpoint helps to clarify how

environmental stimuli operate on the human organism and

it helps to specify more precisely which stimuli sponsor

criminality and which do not

• Genetic influences on criminality are complex and

multifaceted – It’s simply not the case that “bad genes”

create “bad” people

• There’s ample reason to believe that serious misbehavior

may also respond well to the combination of

pharmaceuticals and individual and family counseling

Conclusions

• The earlier the age of onset of problem behaviors the

more likely those problems are to become resistant to

change

• This evidence points to the need for early intervention

with high-risk children and their families

• It’s unreasonable to expect that even our best efforts to

habilitate or rehabilitate a criminal individual will be

successful in all cases

Conclusions

• Even among offenders, serious predation is not common – the crimes these men commit are typically the most serious and the most brutal

• Perhaps the most important contribution to behavioral genetics is its focus on consilience

• As an overarching perspective, the field of behavior genetics offers invaluable insights into the origins of predatory criminal conduct

Documents

Chapter 3: The Behavioral Genetics of Predatory Criminal Behavior John Paul Wright Kevin M. Beaver