From the earliest days of criminological enquiry, family factors have been central to explanatory models of youth crime. Empirical studies on the effects of ‘broken homes’ began as early as the 1920s (Wells and Rankin 1991), and today, searches of electronic databases identify literally thousands of reports examining links between family structure, family functioning, styles of parenting and youth crime. This huge body of research has established beyond doubt that delinquency is more common in some family forms than in others, and shows systematic links with styles of parenting and patterns of family life. Research on parenting has contributed directly to the development of some of the best-supported interventions for childhood conduct problems, and much public and policy debate turns on the findings of family-related research.