Personality Trait Change in Adulthood Brent W. Roberts Daniel Mroczek

FULL DISCLOSURE

Review Focus –Average change over a sample or population –Individual differences in the rate of change

Cross-sectional Studies Reviews Srivastava et al. (2003) –Large internet-based study (N = 132,515) –Results Size and direction of differences consistent with previous findings, but interpreted as change Roberts and Mroczek’s claim that “60-year-old participants scored higher than 40-year old participants on most dimensions…” (no basis for this claim!)

Longitudinal Studies Reviews 2006 Roberts et al. paper –92 longitudinal studies covering ages –Found significant change in 75% of traits in middle (40-60) and old (60+) age –Figures (Figure 2 from meta-analysis) Standardized measure of mean differences How much of a standard deviation –Costa and McCrae (2006) noted that these are the same modest changes they had been reporting for some time

Individual Differences in Change Two levels of change –Mean levels of change –Individual differences in change Do some individuals change faster? Do some individuals change in a different direction? Multiple ways to assess –RCI –Growth models

Individual Differences in Change Used to illuminate why people change or what change is related to –People who experience satisfying careers show greater declines in N and increases in C –Long-term increases in N are related to mortality (Mroczek & Spiro, 2007) –Increases in Ho are related to mortality (Siegler et al., 2003)

Personality Plasticity After Age 30 Antonio Terracciano Paul T. Costa, Jr. Robert R. McCrae

Main Study Question Longitudinal data suggest that –Personality is relatively stable –Stability is greater in adulthood than in prior years When, if at all, does rank order stability plateau?

Differential Predictions

Methods Baltimore Longitudinal Study of Aging –Large sample for part of a multidisciplinary study –Recurring assessment Measures –GZTS –NEO and NEO-PI-R –California Adult Q-Set

Rank Order Stability Results Across domains –NEO: rank order stability did not differ between age groups –GZTS: rank order stability did not differ between age groups At scale level –Extraversion domain showed more stability in than > 65 group –Not replicated in similar GZTS scales

Personality Trait Development From Age 12 to Age 18: Longitudinal, Cross-Sectional, and Cross-Cultural Analyses Robert R. McCrae and others

Purpose To assess mean-level personality change in adolescence Also… –Compare longitudinal results to cross- sectional data from the U.S. –Examine factor invariance –Rank-order stability

Methods Participants –521 boys and 249 girls –Scored above 97 th percentile in academic ability –230 students were assessed four years later Instrument –NEO-FFI –Short version of the NEO-PI-R

Factor Invariance Compared structure of first and second ratings –CFA simple structure model CFI suggested poor fit RMSEA suggested good fit Constraining factor loadings to be identical across intervals caused decreases in fit, but no change in CFI or RMSEA –Procrustes rotation Coefficients for N, E, and C greater than.90 Coefficients for O and A greater than.85

Retest Reliabilities Considerably lower than in older samples –Boys Range:.31 for A to.49 for C Median:.39 –Girls Range:.30 for N to.63 for C Median:.34

Mean Level Differences MANOVA –DVs: Five NEO-FFI domain T-scores –IVs: Gender, Time –Interaction: Gender × Time Results –No main effects of Time for N, E, or A –O increased and C decreased –Gender × Time effect on N

Differences for boys

Differences for girls