Cross-sectional age differences in personality: Evidence from nationally representative samples from Switzerland and the United States

Identifying reliable patterns of age differences in personality can help clarify the nature of adult personality development. Previous studies have been limited because many have relied on convenience samples. In this study, we examined age differences in personality in two nationally representative samples, one from Switzerland and one from the United States. The results indicated that Agreeableness and Conscientiousness were positively associated with age, whereas Extraversion was negatively associated with age. However, the magnitude of age differences for Extraversion was much smaller than for Agreeableness and Conscientiousness. Openness showed a more complex trend such that 30- to 34-year-olds scored lower on Openness than younger age groups, whereas older groups scored somewhere in between. Inconsistent age differences were observed for Neuroticism.