ABSTRACT Big Five and affective traits were measured at three assessments when participants were on average 18, 21, and 24 years old. Rank-order stability analyses revealed that stability correlations tended to be higher across the second compared to the first retest interval; however, affective traits consistently were less stable than the Big Five. Median stability coefficients for the Big Five increased from .62 (Time 1 vs. Time 2) to .70 (Time 2 to Time 3); parallel increases also were observed for measures of negative affectivity (median rs=.49 and .55, respectively) and positive affectivity (median rs=.48 and .57, respectively). Growth curve analyses revealed significant change on each of the Big Five and affective traits, although many of the scales also showed significant variability in individual trajectories. Thus, rank-order stability is increasing for a range of personality traits, although there also is significant variability in change trajectories during young adulthood.