Cross-sectional age differences and longitudinal age changes of personality in middle adulthood and old age.

The present study examines different aspects of personality continuity (or change) in middle adulthood and old age both cross-sectionally and longitudinally. The sample comprised 445 middle-aged (42-46 years) and 420 older (60-64 years) participants, reassessed after a 4-year interval. Personality was measured using the NEO-FFI personality inventory. After having established strict factorial invariance, factor covariances were found to be equal for both age groups and at both testing occasions, indicating perfect structural continuity of personality. A number of age differences in personality emerged at both measurement occasions. Longitudinally, in both age groups, an average decline in Neuroticism was observed. Longitudinal stability coefficients were around .80 in middle-aged and old participants, implying high, but not perfect, differential continuity. With respect to continuity of divergence, statistically significant cross-sectional age differences were found for the variance of Openness at both measurement occasions. Eventually, concerning specific versus general continuity, a variety of medium effect-sized correlated changes in the Big Five personality domains across the 4-year period was established, implying that personality changes share a certain amount of commonality.