Convicted criminal offenders had more children than individuals never convicted of a criminal offense

Criminal offenders also had more reproductive partners, were less often married, more likely to get remarried if ever married, and had more often contracted a sexually transmitted disease than non-offenders. Importantly, the increased reproductive success of criminals was explained by a fertility increase from having children with several different partners. We conclude that criminality appears to be adaptive in a contemporary industrialized country, and that this association can be explained by antisocial behavior being part of an adaptive alternative reproductive strategy.

page 4: More specifically, in a review of the literature Ellis and Walsh found that 50 out of 51 studies investigating associations between mating behavior and criminality reported a positive relationship between criminal behavior and number of sex partners (Ellis and Walsh 1997)

Rowe, for instance, argued that “crime results from an evolved behavioral strategy that maximizes mating effort and minimizes parenting effort.” (Rowe 1996). This idea rests on the fact that among mammals in general, males in contrast to females have substantial potential to increase their reproductive success by mating with multiple partners (Clutton-Brock 1991).

page 14:Third and finally, our findings showed that the increased reproductive success among criminal offenders compared to non-offenders is explained by more reproductive partners. Hence, on average, offenders have fewer children with each partner than non-offenders but raise their fertility beyond the general population average by having children with multiple partners. Stronger support, particularly in men, was suggested the more persistent the criminality pattern appeared to be.