Conceptual, and empirical, questions are raised regarding the notion that physical aggression is the main individual risk factor for antisocial behavior, that language impairment also constitutes a risk factor, the meaning of the male preponderance for antisocial behavior, the findings on environmentally mediated risk; the role of biosocial interplay; social context effects; the construct of antisocial behavior, developmental trends; processing of experiences; and transactional effects. The main blocks to using research to develop policy are the lack of evidence on (a) the mediators of the causal processes, (b) what is needed to bring about change, (c) ways to ensure that individuals who need interventions actually receive them, and (d) differences in levels of antisocial behavior.