With no succinct and simple conclusions on the causes of antisocial behavior and offending, there has been considerable progress in unraveling the causal pathways. Highlights of these causal pathways identified in this chapter include: (1) serious family discord and hostility, and the experience of abuse, are an important part of the causal nexus; (2) a lack of employment opportunities and the negative effects of imprisonment are likely to be important risk factors; (3) whereas poverty probably constitutes a weak immediate causal factor, it may be much more important as a distant factor making positive family functioning more difficult; (4) there is good evidence that antisocial behavior is associated with identifiable differences in neural functioning; what remains uncertain is the relative importance of causal influences and of the reverse effects of antisocial behavior on the brain; (5) there is good evidence on the heterogeneity of antisocial behavior, best demonstrated in terms of associations with psychopathy, with inattention/over activity, and with schizophrenia; (6) situational factors were shown to be important years ago and there is no reason to doubt their relevance today; (7) ethnic variations and sex differences are known to be very important, but knowledge is lacking on the implications for causal mechanisms; and (8) it is apparent that not only are there several causal pathways leading to antisocial behavior, but also there are substantial individual differences in people's response to all causal features. Figures, notes, and references