Warring In the Genes

So what is new in genetics research? An old debate still rages: Is it a person's environment or his genetic makeup that causes his violent behavior? Is a serial killer destined to perform his activities from birth, or did he develop his psychiatric abnormalities? What makes a criminal perform aggressive behaviors? 

Scholars have wrestled with such questions for decades. It’s the old nature versus nurture argument. Most likely a combination of the two, environment and genetics, play a part in aggressive behavior. (D.P. Lyle, MD, M"Dangerous DNA: The Warrior Gene," Medical Issues, June 15 2010) Common sense and experience lend credence to understanding a negative past and a bad temper often create a violent, even volatile combination.

But now, a series of studies has identified a male gene that promotes aggression. Boys (Girls do not have the gene.) who carry a particular variation of the gene Monoamine oxidase A (MAOA) may have an inborn link that once played a significant role to human survival. Scientists have nicknamed this culprit the "Warrior Gene."

"Individuals with the so-called "Warrior Gene" display higher levels of aggression in response to provocation, according to new research co-authored by Rose McDermott, professor of political science at Brown University. In the experiment, which is the first to examine a behavioral measure of aggression in response to provocation, subjects were asked to cause physical pain to an opponent they believed had taken money from them by administering varying amounts of hot sauce. The findings are published in the Proceedings of the National Academy of Sciences."  

(Deborah Baum, "'Warrior Gene' Predicts Aggressive Behavior After Provocation,' Medical News Today, January 22 2009)

In addition, boys who carry a particular variation of the gene Monoamine oxidase A (MAOA), the Warrior Genes, are more likely not only to join gangs but also to be among the most violent members and to use weapons, according to a new study from The Florida State University that is the first to confirm an MAOA link specifically to gangs and guns. ( Beaver et al., "Monoamine Oxidase A Genotype Is Associated With Gang Membership and Weapon Use," Comprehensive Psychiatry, June 2009)

The results support previous research suggesting that MAOA influences aggressive behavior, with potentially important implications for interpersonal aggression, violence, political decision-making, and crime. Still, many who carry the genetic characteristic did not act out their violent tendencies.

Doubting Credibility

Claiming a study is not a scientific experiment with a replication, many authorities doubt the findings. Among those are R.L. Clima, Ph.D. who vehemently replied to an airing of "Born To Rage," a recent National Geographic segment about the Warrior Gene with the following:

"Prove it.   Just one will do.  Until you or anyone else does including the geneticists, I implore you and others to stop spreading this crap around the universe.  It does real harm. I will expand on the harm if you need to hear it. 

"BTW, the science of genetics has been in the Model-T era for 50 years, and has made dozens of claims over the years, none of which have been confirmed. None. Zero.  I'll provide examples of this too if you like. 

"Genetics will remain a Model-T science as long as their "scientists" insist that genes influence behavior "because they just do" - and so will their advocates."

But, The Cat Is Out of the Bag

Consider the significance of identifying a tiny bit of DNA that predisposes males to violent behavior. The new research leads scientists to suspect that approximately 30% of all men carry the warrior gene. Carriers of the gene mutation had a doubled chance of joining a gang--meaning that instead of having a 1.5 out of 100 rate of joining a gang, the carriers joined at a rate of 3 of every 100. In other words, 97 in 100 carriers of the warrior gene don't seem to be linked to violence in any sort of meaningful way. With such minor exhibition, how would genetic identification of "aggressive warriors" be handled and for what purposes?

Would the Armed Services be interested in identifying such aggressive inductees for special services? Would juvenile delinquents be made to submit samples for genetic profiling and future reference? Would a despotic maniac like Hitler attempt to use such information in eugenics manipulations? And, would this be the start of an age in which genetics would be used as a defense for any crime or violent action?

In fact, the genetic defect defense has already been used successfully in the courts of Tennessee. In a groundbreaking case, a jury found Bradley Waldroup guilty of voluntary manslaughter rather than murder in the death of Leslie Bradshaw. He also was found guilty of the attempted murder of his wife, Penny Waldroup, and two kidnapping counts. Waldroup said on the murderous night, he just "snapped," and he admitted that he had killed Leslie Bradshaw and attacked his wife. "I'm not proud of none of it," Waldroup said. Here is a synopsis of the trial. (Todd South, "Warrior Gene Featured in TV Show," Chattanooga Times Free Press, December 12 2010)

"In October 2006, Waldroup killed Leslie Bradshaw by shooting her eight times and slashing her in the head with a machete. He also chased his wife through the woods, shooting and hacking her, but she survived. Prosecutors originally sought the death penalty, and the 32-year prison sentence that Waldroup received surprised many in the community.

"Prior to the trial, Young and her co-counsel, Wylie Richardson, consulted with Dr. William Bernet, a Vanderbilt University psychiatrist who tested Waldroup for Monoamine Oxidase A, commonly called the 'Warrior Gene.'

"Waldroup has the gene, and that evidence was admitted at trial, along with his abusive history and alcohol use at the time of the crime."

According to NPR reporter Barbara Bradley Hagerty, scientists and legal experts expect to see more cases like this as neuroscience makes inroads into the courtroom, and presents guilt and innocence — not in terms of black and white — but in shades of gray. Genetics, as cloudy as it is, is definitely being considered as a source of violent behaviors.

And A Parting Thought For the Holidays... 

Now, a test ($79.00 from www.familytreedna.com) is available for those who wish to discover whether they have the Warrior Gene genetic variant. Here's an idea for a unique Christmas present. I wonder how old Saint Nick would fare on the DNA swab?

For others who don't wish to invest, here is the link for the Warrior Quiz from National Geographic.
http://channel.nationalgeographic.com/series/explorer/4833/Overview33#tab-quiz