Scientists discover "gangsta gene."

Life ain't nothin' but money and bitches and monoamine oxidase proteins. From ABC News:

It's not nearly as overt as a hand sign or a coloured bandana, but DNA may offer one clue as to whether someone belongs to a gang or not.

Males with a particular form of gene called MAOA are twice as likely to join a gang, compared to those with other forms, finds a new study of more than 2000 US teens. What's more, gang members with these mutations are far more likely to use a weapon than other members.

"For the most part, people haven't really thought of the biological or genetic underpinnings to gang membership, says Kevin Beaver, a biosocial criminologist at Florida State University in Tallahassee, who led the study.

The relatively common mutations result in reduced levels of a protein, called monoamine oxidase A, which recycles several of the chemicals that foster neuron connections.