Age differences in the variance of personality characteristics

In contrast to mean-level comparisons, age group differences in personality trait variance have received only passing research interest. This may seem surprising because individual differences in personality characteristics is exactly what most of personality psychology is about. Because different proposed mechanisms of personality development may entail either increases or decreases in variance over time, the current study is exploratory in nature. Age differences in variance were tested by comparing the standard deviations of the Five-Factor Model (FFM) domain and facet scales across two age groups (20- to 30-year-olds vs. 50- to 60-year-olds). Samples from three cultures (Estonia, the Czech Republic, and Russia) were employed and two methods (self- and informant-reports) were used. The results showed modest convergence across samples and methods. Age group differences were significant for 11 of 150 facet-level comparisons, but never consistently for the same facets. No significant age group differences were observed for the FFM domain variance. Therefore, there is little systematic evidence for individual differences in personality characteristics being smaller or larger in older as opposed to younger people. We discuss the implications of these findings for understanding personality development.