Etiology of antisocial personality disorder: benefits for society from an evolutionary standpoint.

As human society is mainly cooperative, it is not clear how antisocial personality disorder (APD) persists. The current explanation is that sociopaths are cheaters who maximize their fitness by taking advantages from others. Although this argument is valid, we show here that society also benefits from APD. We propose that the old phylogeny of punishment, the fact of being a full member of society, the frequency of the disorder, genetics, linkage between two "contradictory" DSM IV criteria for the disorder, and the necessity for society to fight against antisocial behavior, play positive roles for society and/or human groups, especially in the ancestral environment.