The study found that physical punishment and peer delinquency interacted with psychopathy at age 13 to predict the psychopathy score at age 24; however, boys who were high in psychopathy at age 13 tended to remain high at age 24, regardless of the status of the moderators measured. The important changes in behavior and mental state across time occurred for the boys who were low in psychopathy at age 13. Boys who were low in psychopathy at age 13 and who grew up in wealthier families, had fewer antisocial peers, and experienced less physical punishment remained low in psychopathy across time; however, boys who were low in psychopathy at age 13 and who grew up poorer, had antisocial friends, and experienced more physical punishment became more psychopathic over time. The disappointing finding is that no moderators acted to reduce future psychopathy among those who exhibited the highest levels of psychopathy at age 13. This finding is consistent with previous accounts that suggest psychopathy is an innate temperament that is relatively resistant to socialization efforts by parents and peers. Subjects for this study are members of the middle sample of the Pittsburgh Youth Study. Two hundred and seventy-one of the boys had psychopathy data available at age 13 and were included in the study. Juvenile psychopathy was assessed with the Childhood Psychopathy Scale. Psychopathy in adulthood was assessed with the Psychopathy Checklist: Screening Version. Moderator variables measured at age 13 pertained to demographics, neighborhood socioeconomic status, parenting, peer delinquency, delinquency, and several individual variables. 1 table, 3 figures, and 56 references