The Warrior Gene

My Psych of Violence class, which is generally a very cool class, today discussed the so-called "Warrior Gene". Nat Geo did a piece on it, which is fantastic if you have 45 minutes to watch. But basically, the rundown is this:

The MAOA gene, which is carried on the X-chromosome, helps degrade serotonin and other neurotransmitters. Serotonin, most people know, is one of the bodily chemicals that makes you happy. However, the MAOA enzyme steps in and keeps it from getting too highly concentrated, since too much happy can turn to aggression very quickly.

It turns out that in about 1/3 of males in the Western hemisphere, the MAOA area is shortened or dysfunctional. Case studies exist where the MAOA doesn't work at all, but this is very very rare. It is believed (and there has been some research to support) that for those males with the mutated MAOA who are exposed to violence as a child, there is a significantly increased possibility of violent behavior as an adult. Because it is carried on the X-chromosome, women have a second copy and thus have one working copy of the MAOA gene. I could start a whole other conversation about the value of gene redundancy and the fascinating science involved in the Y-chromosome, but that's another post.

Obviously this is not the only determining factor in aggressive and violent behavior. Also, it is not a pre-determinant behavior. In the video, they tested a group of bikers (one of whom has a seriously violent history), MMA fighters, two (twin) former members of an LA gang, a former Navy SEAL, three Buddhist monks, and Henry Rollins (who was involved in the entire documentary). Of that, half the bikers (but not the really violent one), the twins, the SEAL, and all three monks tested positive for the mutated gene. Rather than associate the gene with violence, it is probably better to associate it with risk-taking (the former SEAL is a huge entrepreneur) and aggressiveness.

There's an ongoing debate in genetic research about how far is too far. The fear of the Nazi eugenics program hangs over everyone in the field, as well as policy makers and the public. A 2009 court case found a man not-guilty of murder and assault because of this gene. It's a touchy topic and part of the debate regarding the value of genetics in our society. No matter where things come down, I dislike the name. Warrior has a certain connotation (a positive one according to my class) that may color the view of violent behavior in someone who happens to have this gene. However the debate goes, however, I am fascinated by it. My behavioral genetics geekery is showing....