Does the Variance of Personality Traits Change Across the Lifespan? A Meta-Analysis of Longitudinal Studies

Although personality traits are relatively stable compared to other constructs, comprehensive meta-analyses show that the mean-levels and rank-orders of personality traits change throughout the lifespan. In contrast, relatively little is known about whether and how the variance of personality traits develops across the lifespan. Examining changes in personality trait variance is, however, critical to contextualize knowledge on mean-level changes, to identify disruptive life phases, to evaluate the predictive utility of personality traits across age, and to advance personality development theories. The present meta-analysis thus integrated research from 362 longitudinal studies (total N = 344,270) to identify changes in personality trait variance across the lifespan. Across traits, we found a remarkable stability of personality trait variance, indicating that people neither get more different nor more alike across time and age. The only deviations from this pattern were found in childhood, suggesting that the variance of extraversion, neuroticism, and openness decreases in the first years of life (ages 1 to 4) and that the variance of neuroticism increases in late childhood (ages 5 to 13). These findings were robust across various publication, sample, and assessment characteristics. Our results provide novel insights into personality trait development that may spark theoretical advancements by incorporating concrete predictions about stability and change of personality trait variance. Furthermore, the stability of personality trait variance illustrates that mean-level changes in personality traits seem to be independent of variance changes and that personality traits have a similar potential to predict relevant life outcomes across the lifespan.