Papers on familial factors in delinquency review research on family factors that prevent and influence delinquent behavior, identify early precursors of frequent juvenile offending, and discuss the diagnosis and treatment of biomedical problems associated with juvenile delinquency. Among the papers on promising early interventions to prevent delinquency, two focus on the effectiveness and improvement of parent training programs as well as some critical teaching issues for parents in the management of resistant children. Three papers on promising preventive early interventions address research on the effectiveness of well-designed preschool programs in preventing subsequent delinquency, the implications of early intervention efforts for the primary prevention of juvenile delinquency, and results and issues from a continuing Seattle program of parent training to prevent delinquency. Four papers focusing on how public policy can facilitate family-oriented delinquency prevention suggest preschool enrollment as an aspect of dispositions in cases of child abuse and neglect, the Federal Government's role in fostering positive family influences, how public policy may affect children's self-concept (labeling theory), and community support for multiproblem families. Chapter references. For individual papers, see NCJ 105610-19.