This study examines the relationships among families, peers, and delinquency by specifying and testing a structural-interactionist theory of delinquent behavior. The key process within this perspective is role taking, the mechanism by which groups control the behavior of individuals, and which, consequently, links social structure to individual action. The concept of role taking or reflective appraisal is operationalized and used to help explain how parents, peers and teachers influence the moral and unlawful behavior of adolescents. The causal mechanisms of conventional theories, are shown to be special cases of a structural-interactionist perspective; this nested structure provides a way of testing the proposed theory against competing explanations. Data for the empirical analysis come from the 1976-1980 National Youth Survey, a longitudinal dataset collected on a national sample of adolescents, aged 11-17. Two kinds of models, each incorporating the processes of roletaking, differential association, and social control, are specified, estimated, and tested. The first, a conventional panel model of delinquency treats the individual as the unit of analysis, and seeks to explain variation in delinquency across persons and over time. The second, a family model of delinquency, treats the sibling pair as the unit of analysis, and attempts to account for both the common variation (covariation) in delinquent behavior for pairs of siblings as well as the variation in delinquent behavior across different pairs of siblings.