We examined how family and child risk factors jointly affected stability and change inexternalizing behavior over time in a prospective study of eventual alcohol use disorder. Studyparticipants were community-recruited alcoholic and control families, and their initiallypreschool-aged male and female children (N = 335). Family risk varied as a functionof both parental alcoholism (ALC) and antisocial personality disorder (ASPD) and was evaluatedfor both parents. Child risk was characterized by a set of risky temperament attributes pertainingto high activity, high reactivity, and low attention span. Externalizing behavior was used as theproxy indicator for later alcohol problems. For children in the high family risk group (involvingcurrent ALC in both parents or current ALC + ASPD comorbidity or both), child risk whenchildren were 3–5 years old (Wave 1) directly predicted externalizing behavior whenchildren were 6–8 years old (Wave 2), even when Wave 1 child risk was controlled for. Inaddition, parents' negative interaction with children at Wave 1 mediated the effect of childrisky temperament on Wave 2 externalizing behavior. No such pattern was observed in the lowfamily risk group, where only autostability effects were predictive of outcomes at Wave 2. Theimportance of nesting structure as an ingredient in the epigenesis of risk was discussed. Itsparticular relevance in understanding the process of risk transmission among offspring fromantisocial alcoholic families was emphasized.