In a 19-year longitudinal study, the 15% most inhibited and the 15% most aggressive children at ages 4-6 years were followed up until age 23 years and were compared with controls who were below average in preschool inhibition or aggressiveness. As adults, inhibited boys and girls were judged as inhibited by their parents and showed a delay in establishing a first stable partnership and finding a first full-time job. However, only the upper 8% in terms of inhibition tended to show internalizing problems, including self-rated inhibition. Aggressive boys showed an externalizing personality profile in the parental and self-judgments, were educational and occupational underachievers, and showed a higher adult delinquency rate than the controls, even after sex and socioeconomic status were controlled. The results suggest delayed social transitions without internalizing problems for most male and female inhibited children and a significant long-term risk of an externalizing profile for aggressive children. (Contains 2 tables and 3 figures.)