Personality Development Two questions of personality development How do we come to have the personalities we do? 1. Personality class provided various

Personality DevelopmentPersonality DevelopmentTwo questions of personality development

How do we come to have the personalities we do?

1. Personality class provided various theoretical perspectives

2. Genes and gene-environment transactions

What happens to personality across development?Change

Stability

Person-environment transactions

How do we come to have the How do we come to have the personalities that we do?personalities that we do?

Long thought to be due to parenting Long thought to be due to parenting and family influencesand family influences Examples: Examples:

parents that read to their children parents that read to their children Parents that are violent and aggressive in Parents that are violent and aggressive in

punishments have children that are punishments have children that are aggressiveaggressive

Etc.Etc.

Role of parentingRole of parenting

Most effects are correlationalMost effects are correlational

Fail to recognize that parents also Fail to recognize that parents also share same genes as childrenshare same genes as children

Twin studies have addressed this Twin studies have addressed this problemproblem

Twin StudiesTwin Studies

MZ twins and DZ twinsMZ twins and DZ twinsSuggests heritability estimates of .5 for Suggests heritability estimates of .5 for

personality traitspersonality traits

Shared environment = what siblings share, Shared environment = what siblings share, parenting practices, neighborhood, family parenting practices, neighborhood, family lifelife

Nonshared environment is everything else. Nonshared environment is everything else. More important than shared environmentMore important than shared environment

Importance of nonshared Importance of nonshared environmentenvironment

1.1. Adult siblings’ personalities are about Adult siblings’ personalities are about equally correlated whether they grew up equally correlated whether they grew up together or apart.together or apart.

2.2. Adoptive siblings are no more similar than Adoptive siblings are no more similar than two random people from same culturetwo random people from same culture

3.3. MZ twins are no more similar than effect MZ twins are no more similar than effect of shared genesof shared genes

Differences may be due to random events that Differences may be due to random events that people experiencepeople experience

What happens to personality What happens to personality across development?across development?

Are traits stable as we develop or do Are traits stable as we develop or do they change?they change?

Is an issue of stabilityIs an issue of stability

Several ways that stability can be Several ways that stability can be studiedstudied

Types of StabilityTypes of Stability1. Intraindividual differences in consistency – how each

individual changes with time

2. Ipsative differences – how the salience of attributes changes within individuals over time

e.g. Block (1971) found a group of men for whom talkativeness and rebelliousness become more important as they moved from teen-age years to young adulthood

3. Mean-level consistency (population level) – looks at whether groups of people increase or decrease on trait dimensions over time

E.g. conscientiousness goes up in adulthood

4. Rank-order consistency (population level) – relative placement of individuals within a group. Do groups of people retain the same rank ordering on trait dimensions over time?

People get taller with age but percentile rank may remain stable

Levels of analysisLevels of analysis

1.1. Population level – those that apply to everyonePopulation level – those that apply to everyone Sexual interest increases at puberty for almost Sexual interest increases at puberty for almost

everyoneeveryone Impulsiveness decreases with ageImpulsiveness decreases with age

2.2. Group differences level – changes over time Group differences level – changes over time that affect groups differentlythat affect groups differently

Male teen-agers are higher risk takers than femalesMale teen-agers are higher risk takers than females White women more at risk for eating disordersWhite women more at risk for eating disorders

3.3. Individual differences level – which individuals Individual differences level – which individuals change over time? Who will be at risk for change over time? Who will be at risk for particular outcomes, etc.particular outcomes, etc.

Rank-Order Stability of Rank-Order Stability of PersonalityPersonality

Roberts, B. & DelVecchio, W. (2000). The rank-order consistency of personality traits from Childhood to old age: A quantitative review of longitudinal studies. Psychological Bulletin, 126, 3-25.

Meta-analysis (combines multiple studies)

152 longitudinal studies

3,217 test-retest correlations

Organized according to Big Five

Rank order stability studyRank order stability study

Interested in whether people retain Interested in whether people retain the same rank ordering on traits over the same rank ordering on traits over timetime

Other types of change may also Other types of change may also occur, but each methodological occur, but each methodological approach addresses a different approach addresses a different questionquestion

Relative Stability of Relative Stability of PersonalityPersonality

Meaning of previousMeaning of previous

Trait consistency steadily increases Trait consistency steadily increases with agewith age

Consistency peaked at 50-59 ageConsistency peaked at 50-59 age Lowest at ages 0 to 3Lowest at ages 0 to 3




Analysis of previous dataAnalysis of previous data

Adult personality traits are more Adult personality traits are more consistent than childhood consistent than childhood temperament traitstemperament traits

Agreeableness & extraversion were Agreeableness & extraversion were most consistent (but other Big Five most consistent (but other Big Five traits also consistent)traits also consistent)

Some change DOES occur in Some change DOES occur in adulthood (in contrast to Costa & adulthood (in contrast to Costa & McCrae)McCrae)


Important conclusions:

Trait consistency increases with age0.31 in childhood

0.54 in college years

0.64 at age 30

Plateaus between 50 and 70 at .74

The longer the interval the lower the stability

Personality more stable than temperament

No differences among Big 5

Costa & McCraeCosta & McCrae

Personality is “set like plaster” by age 30Personality is “set like plaster” by age 30

Some debate about this (ages 50 to 70 appear to Some debate about this (ages 50 to 70 appear to be more stable)be more stable)

Certainly the 20s is an important time to look at Certainly the 20s is an important time to look at for personality developmentfor personality development People often gaining independence from familiesPeople often gaining independence from families Moving awayMoving away Going to college and/or joining workforceGoing to college and/or joining workforce Getting into committed relationships and having childrenGetting into committed relationships and having children

Example: Stability in Example: Stability in ChildrenChildrenMcCrae, R.R., Costa, P.T., Terracciano, A., Parker,

W.D., Mills, C.J., de Fruyt, P., & Mervielde, I. (2002). Personality trait development from age 12 to age 18: Longitudinal, cross-sectional, and cross-cultural analyses. Journal of Personality and Social Psychology, 83, 1456-1468.

Longitudinal study of intellectually gifted students

4 years: 12 to 16

N = 230

NEO-PI-R

Example: Stability in Example: Stability in ChildrenChildren




Example: Stability in College Example: Stability in College StudentsStudents

Robins, R.W., Fraley, R.C., Roberts, B.W., & Trzesniewski, K.H. (2001). A longitudinal study of personality change in young adulthood. Journal of Personality, 69, 617-640.

Longitudinal study of college students

N = 270

Assessed when first entered college and 4 years later

FFI



Mean-level Consistency of Mean-level Consistency of PersonalityPersonality

Srivastava, S., John, O.P., Gosling, S.D., & Potter, J. (2003). Development of personality in early and middle adulthood: Set like plaster or persistent change? Journal of Personality and Social Psychology, 84, 1041-1053

Internet study

N = 132,515

Aged 21 to 60 (cross-sectional)

Completed BFI on-line

Aimed at countering C & M—no changes after 30

Mean-level Stability of Mean-level Stability of PersonalityPersonality



SummarizeSummarize

Mechanisms of ContinuityMechanisms of ContinuityEnvironmental stability

Three types of person-environment transactionsReactive

Different individuals exposed to the same environment, experience it, interpret it, and react to it differently

Example: schemas

EvocativeAn individual's personality evokes distinctive responses form others

Examples: coercive child, happy child

Proactive/SelectiveIndividuals select or create environments of their own

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Personality Development Two questions of personality development How do we come to have the personalities we do? 1. Personality class provided various