Although much of the earlier research illuminating moderate to high continuity in aggression over time focused exclusively on males, sex differences in continuity have been receiving increasing attention as the samples of studies incorporating both males and females have aged. In this study, we observed somewhat greater continuity of aggression for males than we did for females, with some important differences in continuity coefficients across sex. For males, coefficients were statistically significant and in the moderate range for all intervals (rs = .34–.60). For females, aggression at age 8 was only related sizably to aggression at age 19; relations of age 8 aggression to aggression during adulthood were modest (rs<.20). Person-oriented trends in aggression continuity also differed by sex. We found that males who were highly aggressive in childhood were more likely to remain highly aggressive in adulthood than were females who were highly aggressive in childhood. Conversely, we found that females rated at low levels of aggressiveness during childhood were more likely to remain low in aggressiveness in adulthood than were males who were rated low in aggressiveness during childhood.
