Personality Stability and Change Lecture Notes PDF

Personality and Social Psychology Lecture 4: Personality Development and Change Overview of my lectures Introduction to personality (week 2) What is personality? History and measurement Correlation and regression (week 3) Analysing data in personality and social...

Personality and Social Psychology Lecture 4: Personality Development and Change Overview of my lectures Introduction to personality (week 2) What is personality? History and measurement Correlation and regression (week 3) Analysing data in personality and social psychology Personality: Development and change (now) Is our personality stable across the lifespan? Can we choose to change? Personality and consequential outcomes (week 5) The predictive power of personality Achievement, health, quality of life, social indicators Persons and situations (week 6) The ‘person-situation debate’ Is personality ‘fixed’, or does it change? “in most of us, by the age of 30, the character has set like plaster” —William James Is personality ‘fixed’, or does it change? “Give Me the Child Until He is Seven, and I Will Show You the Man” —Aristotle  Something persists … Mischel et al. (1972, 2011): 4 year-old participants complete a “delay of gratification” protocol. “Wait times” predict: During adolescence (~10 years later)… Higher SAT scores, coping skills Aggression (lower) During adulthood (~30 years later)… Educational achievement Drug use (lower) Health Conclusion: something about us is stable over time? From “Temperament” to Personality In children… developmental psychologists study “Temperament” Temperament = individual differences in affect, (behavioural) activity, and self-regulation Somewhat narrower than personality, mostly on patterns of behaviour and emotion Partly for methodological reasons: Observational protocols (vs self-reports) Temperament and personality are “different ways of describing the same basic traits, with ‘temperament’ typically referring to earlier forms of these traits and ‘personality’ to later forms” Shiner & DeYoung, 201 From “Temperament” to Personality e.g., Mary Rothbert’s model: Three factors, later expanded to five… 1. Surgency (high activity, positive emotion) 2. Negative emotionality (sadness, irritability, high arousal) 3. Effortful control (sustained attention, persistence in tasks/activities) 4. Affiliativeness (enjoyment of social contact) 5. Orienting sensitivity (enjoyment of sensory experiences) Structure of temperament changes over childhood… Rothbart, 2011; Rothbart & Bates, 2006; Rothbart & Derryberry, From “Temperament” to Personality The “Little Six” (Soto, 2016) Organizes temperament traits in terms of the Big Five + a sixth dimension: activity e.g., Rothbart’s Model: surgency ~ extraversion, effortful control ~ conscientiousness, etc. Structural changes… Some traits emerge earlier (e.g., neuroticism) than others (e.g., conscientiousness) Activity gradually merges with (high) extraversion and (low) conscientiousness Temperament becomes ‘psychologically elaborated’ e.g., Little Six neuroticism: “Cries easily” vs. Big Five neuroticism: “Tends to feel depressed, blue” Caspi & Shiner, 2006; Shiner & DeYoung, 2013; Tackett et al., 2008; Soto & Joh What do we mean by ‘stability’? Rank-order vs. mean-level vs. individual stability time time time t r a i t l e v Perfect rank order, Rank order stability, Rank order stability, e mean level, and Mean level change, mean level stability, l individual stability individual change and individual change  Rank order stability [Not actual data – for visualisation only] Aka test-retest reliability [wk3] Costa & McCrae (1994): Trait level at age 60  Test-retest correlations in adulthood: ~ 0.65 for the B5 traits up to 30-year periods If one is above average on a trait at age 30, there’s an 83% chance (5:1 odds) they will be above average at age 60 Trait level at age 30 Rank order stability Damian et al. (2019): 1, 795 US residents ages 16 to [for visualisation only] Trait level at age 66 66 Test-retest correlations ~ 0.30 for the big five over 50 years Dyson et al. (2015): Trait level at age 16 446 children aged 3 to 6… Test-retest correlations of ~ 0.30 for temperament dimensions over 3 years [Laboratory Temperament Assessment Battery: Positive affect, sociability, dysphoria, Rank order stability Four insights from this literature: Rank-order stability … 1. Is relatively high (r >.30) 2. Increases over the lifespan (from ~ 0.41 in childhood to ~ 0.55 at age 30, to ~ 0.70 at age 60). 3. Decreases as the test-retest interval increases (>.60 over a 1-year period, ~.30 over a 40-year period) 4. Is trait general, i.e., does not vary across: - Big Five traits - Assessment method (e.g., self-reports, observer ratings) - Gender Roberts & DelVecchio, 200 What influences rank-order stability? Proposed explanations: Genetic influences Genetic influences on patterns of behaviour/experience Environmental channeling Our environments naturally stabilize over time ‘Settling down’—consolidation of routines, friendships, career, etc. Environmental selection We actively choose environments that match and reinforce our traits Leisure pursuits, travel, changing jobs or relationships etc.  Influences on rank-order stability What does the evidence say? Genetics… McGue et al. (2003): 79 MZ twins and 48 DZ twins studied from age 20-30. 70-90% of stability owing to genetic factors 70% of change owing to environmental factors Genetic relatedness accounted for aTrait at T1Trait at T2 Genetic relatedness accounted large part of the test-retest reliability for a small part of the (i.e., T2 trait variance predicted by unpredicted variance T1 trait variance)  Influences on rank-order stability Environmental channelling… Caspi & Herbener (1990): 126 married couples given personality assessments in 1970 and 1981 Rank order stability was higher for couples with more similar personalities (But stability still moderate-high for low similarity couples)  Influences on rank-order stability Environmental selection… Evidence that personality influences environment selection… Assortive mating: Trait correlations between romantic partners, up to r =.35 Migration: Personality predicts movement between cities/countries Vocational choice: Personality predicts choice of major and vocational choice [next week] …but little evidence that environmental transitions impact personality stability e.g.,ettest-retest McCrae al., 2008; Roberts, 2006; stability Rentfrow similar et al., 2008; migration throughout Vedel, 2016; vs Youyou non-et al Influences on rank-order stability Overall Picture Genetic influences: Longitudinal twin studies demonstrate “a strong and relatively stable genetic foundation of individual differences in personality throughout the adult life span” (Bleidorn & Kandler, 2014) Environmental influences: Some clues, but “the evidence for environmental consistency promoting personality consistency is weak at best” (Roberts, 2006)  Mean-level personality change time t Soto (2016): r Complex developmental a i patterns in the Little Six t from age 3-16… l e Extraversion, agreeableness, v openness, and activity e decrease l Conscientiousness decreases and then increases again Neuroticism increases and then decreases again (but different trajectories for boys/girls)  Mean-level personality change time Costa & McCrae (1994): t r Review of the adult literature a O, E & N decreases i A and C increases t l Bleidorn et al. (2009): e v 10-year longitudinal study, adults e aged 18-59… l A and C increased O and N decreased No change for E, but diverging patterns at the facet level… Assertiveness increased Gregarious and excitement-seeking  Mean-level personality change Meta-analysis by Roberts et al. (2006): 1.2 1 0.8 Social Vitality 0.6 Social Dominance Agreeableness 0.4 Conscientiousness 0.2 Emotional Stability Openness 0 15 20 30 40 50 60 70 -0.2 -0.4 Mean-level personality change Mean-level change seems to be broadly positive, toward “Psychosocial Maturity” People to become nicer, more responsible, more set in their ways, more assertive/confident, and to experience less negative emotion… Patterns of mean-level personality change are… “Adaptive”, or linked with positive outcomes, such as wellbeing, career success, and health [more next week] Desirable, or positively evaluated (e.g., personality change goals…) Thus, “personality development and maturation” Allport, 1961; Anglim et al., 2020; Hudson & Fraley, 2 What influences mean-level change? Proposed explanations: Genetic influences Evolved maturation processes for “developmental tasks” O and E less essential after reproduction? C and A more helpful during parenthood? Environmental effects Major life transitions / stages / role shifts Effects of gaining independence from parents, transition to work, etc. World / historical events Possibility of cohort effects? Sources of mean-level change The evidence: Genetic influences… Loehlin (1993): Trait change scores correlated.50 for MZ twins vs.18 for DZ twins Suggestive of genetic ‘switches’ driving mean-level change However, Hopwood et al. (2011): 624 twin pairs assessed 3x over 12 years (late teens – late 20s) Estimated genetic and environmental influences on change scores Conscientiousness: genetic effect > environment effect Neuroticism: only a significant environment effect (minimal change observed for other traits) Sources of mean-level change Environmental influences… Cross-cultural comparisons… McCrae et al. (1999): Age-trait associations in 7,363 persons from Germany, Italy, Portugal, Croatia, South Korea Personality differences generally matched patterns of mean level change in the US… Except N: similar to US only in German and Korean sample  Sources of mean-level change Conscientiousness:  All change effects significant McCrae et al., 1999  Sources of mean-level change Neuroticism:  Only significant in German & Korean samples McCrae et al., 1999 Sources of mean-level change Chopik & Kitayama, (2018): 9-year study of mean-level change in the US (N = 6,259) and Japan (N = 1,021): Changes in A, O, E, and N were similar between countries For C, contrasting trajectories…  Peak in US conscientiousness earlier compared to Japan US trajectory Japan trajectory Sources of mean-level change Terracciano, (2015): Review of cross-cultural studies of mean-level change: Studies spanned a wide range of cultures/nations (from all continents), incl. one study comparing 62 nations. Overall conclusion: “the pattern of [mean-level] personality development is remarkably similar across cultures.” Suggests cross-cultural generality of mean-level personality change Sources of mean-level change Cross-species comparisons… King, Weiss, & Sisco, 2008: Mean-level personality change in Chimpanzees (N = 202) in US zoos Results O, E & N decereased over time A increased C increased (but not significantly) Similar patterns to humans – suggests cross-species generality of mean-level personality change Evolved ‘maturation processes’? Sources of mean-level change Environmental influences… Major life transitions — transition to work… Roberts, 1997: ~100 women followed up for ~20 years (early 20s-40s), from late 1950s-1980s Greater participation in the workforce associated with increases in ‘agency’ (part of E) Potentially contributes toward typical mean level changes? But this could also be an environmental selection effect… Sources of mean-level change Major life transitions—transition to parenthood… Avison & Furnham, 2015: Adults with (or desiring) children vs. voluntarily childless adults: Higher in E, A, and lower in O This could also be an environmental selection effect… Sheppington et al., 2017—longitudinal study: 2,469 adults aged 17-45 with no children in 2005 followed up in 2009 556 had their first child between 2005 and 2009 No significant mean-level change in parents vs non-parents Evidence for environmental selection: Those who had children were higher in E and lower in O at baseline Sources of mean-level change Cohort effects? Is personality influenced by broad historical / societal shifts? e.g., exposure to war or adversity, or changes in technology?  Jean Twenge’s ‘generation me’ Claim: American Gen Xs (born 60s-80s) and millennials (80s-90s) have inflated self-esteem, egotism, and expectations of the future Explanation: Relative affluence and “culture of self worth” throughout the 1970s-1990s Evidence for cohort effects? Criticisms of Twenge’s studies: Sampling issues (not representative) Over-estimation of effect sizes (individual vs aggregated scores) Individual data β =.02 Aggregate data β =.81 Trzesniewski & Donnellan, 2010 Evidence for cohort effects? Large-scale test of ‘generation me’… ~500,000 US high school students sampled from 1970- 2006 Completed various psychological and personality assessments Results: No evidence for inflations in self-esteem / egotism Moderate increases in educational aspirations, and decreases in concerns about social problems (rs ~.20) Otherwise very small changes (rs ~.10) Trzesniewski & Donnellan, 2010 Evidence for cohort effects? Another test – New Zealand Assessed ‘entitlement’ (e.g., “I feel entitled to more of everything”) Representative NZ sample (N = 10,412) Compared both age-related trends (from age 19-74) and mean-level change (from 2009 to 2014) Results: Negative relationship between entitlement and age Increases in agreeableness? No increases in entitlement among younger participants Similar findings in Canada and Australia (Hamamura et al., 2020) Stronge et al., 2018 Sources of mean-level change Overall Picture Genetic influences: Some evidence for genetic contributions to mean-level change At least some degree of cross-cultural generalisability Some evidence for cross-species generalisability  Suggestive of universal/evolved maturation patterns Environmental influences: Genetic studies also provide some evidence for environment contributions to mean-level change But…difficult disentangling effects of specific environmental variables on trait change from environmental selection effects Weak support for cohort effects Individual Change time Individual differences in personality change (Roberts & Mrozek, 2008) The Big Five change in ways that vary across individuals in the direction and rate of change. Why? Rank order stability, mean level stability, and individual change The role of life events and experiences Individual Change Shwaba & Bliedorn, 201 Individual Change For all traits except N, magnitude of individual change gradually decreases over the lifespan… e.g., for Agreeableness: “With so much variation in the nature and timing of major life experiences, it is perhaps not surprising that individual differences in personality change are greatest during this stage of life.” Shwaba & Bliedorn, 201 Individual Change May have important practical implications… e.g., Health Conscientiousness predicts health, and increases in conscientiousness predict improvements in health e.g., Mortality Neuroticism predicts mortality, and increases in neuroticism predict shorter lifespan [More on this next week!] Mroczek & Spiro, 2007; Takahashi et al., 20 Individual Change Transition to work (again): People often have different experiences during these transitions Roberts et al., 2003 ~1,000 young adults followed up for ~10 years Personality predicted positive work experiences (occupational attainment and financial security) Positive work experiences also predicted changes in personality (increased E, decreased N)  Individual Change Transition to work (again): Extraversion – individual change but no mean level change: Extraversion Roberts et al., 2003  Individual Change Transition to work (again): Neuroticism – individual and mean level change Neuroticism Roberts et al., 2003  Individual Change Effects of travel / temporary migration: University students on ‘study abroad’ for 1 or 2 semesters (N = 527) vs control students (N = 607) Selection effects: Abroad for 6 months: higher E and C Abroad for 1 year: higher E and O Effects of travel: Increases in O and A Decreases in N immerman & Nyer, 2013  Individual Change O Travel… Change across 1 year of study abroad N A immerman & Nyer, 2013  Individual Change Impact of clinical interventions... Roberts et al., (2017), meta-analysis of 207 studies: Lasting changes, especially for decreased neuroticism (also increased extraversion) Magnitude of change similar across therapy type (e.g., pharmacological, cognitive behavioural, etc.) Non-linear impact of therapy duration: 4 SDs over 20 years!  Can we choose to change? 3. How did they change…? Via counter-dispositional behaviour: Goals  personality states  change in traits For E, A and N only But also via ‘identity’: Goals  change in traits  personality states For E, C and N only NB: No mediators identified for changes in openness Individual change Overall Picture Individual personality change has been linked with various life events/experiences Transition to work, travel, clinical interventions, etc Evidence for both socialisation effects (change follows event/experience) and selection effects (change precedes event/experience) People want to change and appear able to achieve change goals Major caveat: Correlation doesn’t equal causation: We can’t randomly assign people to different life events/experiences (incl. goals to change) Pre-existing differences may therefore still play a role  Overall Summary Personality structure changes throughout childhood: Childhood temperament becomes elaborated into adult personality Can be described via the ‘Little Six” Rank-order stability is moderate-high and increases over the lifespan: Does not differ by trait Twin-studies implicate both genetic and environmental influences But specific environmental effects difficult to find Mean-level change occurs throughout the lifespan: Differs markedly by trait; described as ‘psychosocial maturity’ Evidence for genetic/universal/evolved maturation processes Environment effects (e.g., life transitions) difficult to separate from selection effects Weak evidence for cohort effects Individual change also well documented: Linked with life events and experiences People may be able to volitionally change (e.g., via personality states) But causality remains ambiguous So, our personality changes but is also stable The Song Remains the Same… From Wilt et al., (2012)… Patterns of personality are like the patterns of music, a melody A song can be reinterpreted or remixed, …but still recognised https://www.youtube.com/watch?v=0IagRZBvLtw https://www.youtube.com/watch?v=9Es5Ru6K9FE https://www.youtube.com/watch?v=EjAX9w74TmA https://www.youtube.com/watch?v=SI3amze-aI0 Reading for this week On LMS: Roberts et al. (2008) - A really great review on stability/change In Haslam & Smillie (2022) Chapter 8