Individual Differences in Personality Trait Changes Across the Lifespan: A Meta-Analysis of Longitudinal Studies

Recent meta-analyses and large-scale longitudinal studies have shown that the mean-levels and rank-orders of personality traits change throughout the lifespan. However, people differ from each other in their patterns of personality development. These individual differences in personality trait changes provide important insight into the sources and course of personality development. The present meta-analysis quantified the magnitude of individual differences in personality trait changes and their fluctuation across time and age by integrating findings from 229 longitudinal studies (N = 230,492). Results indicated significant individual differences in change in all traits, with neuroticism showing the most pronounced differences, and openness and agreeableness the least. Charting effects across the lifespan, individual differences in change were most pronounced in childhood, decreased during young adulthood, but were significant across the entire lifespan. The age at which individual differences in change were smallest varied across traits, from ages 30 to 75. Finally, individual differences in personality trait changes were larger over longer assessment intervals, for facet-level traits, and among measures that were not designed to examine the Big Five taxonomy. Our findings support theoretical claims that highlight the relevance of genetic and environmental sources of personality development and suggest that individual differences in change endure, challenging the predictions of set-point models of personality development. Moreover, our results provide benchmarks for individual differences in change that can be used to compare the magnitude of differential personality development in future research.