This final chapter integrates the findings in this book. Tables 17.1 to 17.4 summarize the ‘take-home’ messages from the various studies conducted for this book, and in the following paragraphs we extract unifying themes from these findings to develop recommendations for future research. Based on the findings in this report, two high-priority areas for future research suggest themselves. These priorities are: (a) research into a set of critical individuallevel neuro-developmental factors, and (b) research into a set of influential social contexts. These two priority areas map at least partly on to the typology of life-course persistent and adolescence-limited antisocial behaviour that was presented in chapter 16. On the one hand, a consequential few male offenders (and the rare female) exhibit the life-course persistent pattern. When the objective is to understand the origins of this persistent serious form of antisocial behaviour, this chapter will direct scientific attention toward the neuro-developmental factors that account for the male excess of antisocial behaviour. On the other hand, the majority of male offenders and virtually all female offenders appear to share the adolescence-limited pattern. When the objective is to understand the origins of this situational form of antisocial participation, this chapter will direct scientific attention toward social-context factors that can make females act antisocially along with males. In both cases, the chapter may be read as a template for harnessing sex differences to articulate hypotheses about the origins of problem behaviour.