Thus far we have reported evidence that as they enter adulthood females, relative to males, commit fewer crimes, are less likely to be involved in serious or violent crime, and their antisocial disorders are less likely to persist beyond adolescence into adulthood (see chapter 13). The exception to this pattern is that young women are as likely as young men to be involved in violence within their intimate relationships (see chapter 5). This suggests the need to examine in greater detail the types of men with whom antisocial females form intimate relationships. In addition, it has been remarked that although women who have conduct problems are seldom serious and violent offenders, they are the mothers who produce the next generation of serious and violent males (Henry et al., 1993; Tremblay, 1991). An examination of assortative mating may help us to understand how this might occur.

By age 21, many of the Dunedin Study members were involved in committed intimate relationships with partners and, through de facto unions and marriages, some Study members already moved from their families of origin into new families of ‘destination’. In this chapter, we examine who pairs off with whom and test whether antisocial females, as well as antisocial males, are likely to form unions with other antisocial persons. We also examine the consequences of assortative mating for the persistence of antisocial behaviour into adulthood, as well as the implications of this assortative mating for reproduction.