http://news.yahoo.com/s/livescience/20090605/sc_livescience/boyswithwarriorgenemorelikelytojoingangs

Boys who have a so-called "warrior gene" are more likely to join gangs and also more likely to be among the most violent members and to use weapons, a new study finds.

"While gangs typically have been regarded as a sociological phenomenon, our investigation shows that variants of a specific MAOA gene, known as a 'low-activity 3-repeat allele,' play a significant role," said biosocial criminologist Kevin M. Beaver of Florida State University.

In 2006, the controversial warrior gene was implicated in the violence of the indigenous Maori people in New Zealand, a claim that Maori leaders dismissed.

Controversial, because it implied a link between race and violence, I suppose.

Imagine the hell which would break loose if Africans were the subject of such a study.