One explanation for gender differences in levels of criminality is that men and women are simply different. Whether one takes a sociobiological approach and considers physical/genetic differences between the sexes, or prefers to emphasise gender socialisation, the suggestion is that "normal" masculinity is far more open to criminality than "normal" femininity. Socialisation to be tough, dominant, for example, tends more to criminality than socialisation to be nurturing and compliant. Of course, this could be a very outdated view.