The study began in 1983 and used a cohort-sequential design to study the role of family management practices, family contextual variables, and peer influences on the development of antisocial behavior, chronic delinquency, drug abuse, and depression in cohorts of 102 and 104 boys. The findings indicate that parent-child interaction is the critically important setting where children's behavior problems develop. In addition, children's troublesome behavior places them at risk for rejection by the conventional peer group in the school context. Furthermore, this peer rejection increases the likelihood that the troublesome child will develop a friendship network composed of deviant peers. Next, the development of deviant friends may have a long-term negative impact by providing a social context in which antisocial behavior can be practiced and reinforced. This social context also provides a source of reinforcement for problem behavior that increases the likelihood of negative adult outcomes and interference with developmental tasks such as finishing high school or obtaining work skills. The research also indicates that interventions aimed at parenting practices may be more successful than ones focusing only on peer processes and adjustment. Figures, tables, and 62 references.