In sports, business or your personal life, how you respond to stress and aggression may be in your genes, or at least partly so. Let’s take a look at a great documentary and the science behind it.
Human behavior is complex and influenced by our genes, our environment, and our circumstances. One of the most provocative and often controversial of genetic variants has been dubbed the “Warrior Gene.”
Studies have linked the “Warrior Gene” to increased risk-taking and to retaliatory behavior. Men with the “Warrior Gene” are not necessarily more aggressive, but they are more likely to respond aggressively to perceived conflict.
On December 14, 2010, National Geographic Channel’s Explorer: “Born to Rage?” documentary investigated the discovery behind a single “warrior gene” directly associated with violent behavior.
With bullying and violent crime making headlines, this controversial finding stirs up the nature-versus-nurture debate. Now, former Grammy-winning rocker, author and radio/television broadcaster Henry Rollins goes in search of carriers from diverse, sometimes violent backgrounds who agree to be tested for the genetic mutation. Who has the warrior gene? And are all violent people carriers? The results turn assumptions upside down.
A rock band front man. A bullet-scarred Harley rider. A former gang member from East L.A. Even a Buddhist monk with a far-from-peaceful past. Which one carries the gene associated with violence? An extraordinary discovery suggests that some men are born with impulsive, aggressive behavior … but it’s not always who you think.
It’s a hotly debated topic: nature versus nurture. Many experts believe our upbringing and environment are the primary influences on our behavior, but how much are we predisposed by our DNA? The discovery of a single gene variation affecting only men, which appears to play a crucial role in managing anger, argues that nature may have a far bigger influence on behavior. It’s this low-functioning, shortened gene linked to violent behavior that has become known as the “warrior gene,” and one-third of the male population has it.
One of those men, who describes himself as “fairly furious all the time” and agrees to be tested for the gene with a simple cheek swab, is Henry Rollins — a former poster boy of youthful rebellion and the American punk scene. Some of his tattoos are too provocative and socially offensive to show.
In this special Explorer episode, he dives into his own history of rage and searches out others with aggressive behavior from a range of different backgrounds. “If you can think of a stove, and the pilot light is always on, always ready to light all four burners, that is me, all the time,” he says. “I’m always ready to go there.”
Follow Rollins as he meets with former foot soldiers in one of the most violent street gangs in East Los Angeles; fighters in the ultraviolent sport of mixed martial arts, and Harley Davidson bikers. He’ll also talk to a Navy SEAL veteran and Buddhist monks whose lives weren’t always so tranquil.
After learning more about the warrior gene, many of the men believe they have it, which could offer an explanation of their past behavior. Their sentiment mimics Rollins as he says, “If I find out that I have the warrior gene, that would be interesting. If I find out I don’t, I must say, I would feel a bit of disappointment.” As the anticipation builds, be there when they receive the surprising outcome of the test.
Then, Explorer takes a look at the original study — on one family with generations of men displaying patterns of extreme physical aggression — that led Dutch geneticist Dr. Han Brunner to the revolutionary discovery of this rare genetic dysfunction. We’ll also take a look at new revelations that warrior gene carriers are significantly more likely to punish when provoked. In one study attempting to demonstrate this, subjects are given permission to administer punishment to their partner (who was secretly instructed to make a nuisance of himself), with unexpected results.
For any man questioning his inner warrior, a simple cheek swab test is available at Family Tree DNA.
So wanna know who, in the documentary, had the warrior gene? Well, hint….it wasn’t the biker…although his lady assured him he would always be her warrior. But I’m not going to tell you who does have it. All I’ll say is that you’ll be amazed at the outcome. The link to watch the video is below. Enjoy!
Let’s take a look at the actual science behind this most interesting and controversial mutation.
The Warrior Gene is a variant of the gene MAO-A on the X chromosome and is one of many genes that play a part in our behavioral responses. The “Warrior Gene” variant reduces function in the MAOA gene. Because men have one copy of the X-chromosome, a variant that reduces the function of this gene has more of an influence on them. Women, having two X-chromosomes, are more likely to have at least one normally functioning gene copy, and scientists have not studied variants in women as extensively.
Recent studies have linked the Warrior Gene to increased risk-taking and aggressive behavior. Whether in sports, business, or other activities, scientists found that individuals with the Warrior Gene variant were more likely to be combative than those with the normal MAO-A gene. However, human behavior is complex and influenced by many factors, including genetics and our environment. Individuals with the Warrior Gene are not necessarily more aggressive, but according to scientific studies, are more likely to be aggressive than those without the Warrior Gene variant.
This test is available for both men and women, however, there is limited research about the Warrior Gene variant amongst females. Additional details about the Warrior Gene genetic variant of MAO-A can be found in the paper titled “A functional polymorphism in the monoamine oxidase A gene promoter” by Sabol et al, 1998.
When testing for the Warrior Gene, we are looking for an absence of MAOA (monoamine oxidase A) on the X chromosomes. Based on how many times we see the repeat of a certain pattern on the X or Xs we can tell if the MAOA is present or absent (depleted). Three repeats of the pattern indicates that the X chromosome is deficient of MAOA and therefore you have the Warrior Gene. If we see 3.5, 4 or 5 repeats of the pattern, MAOA is present and this is a normal variant of the gene on your X chromosome.
However, women have 2 X chromosomes where men have 1 X and 1 Y. As mentioned above, the gene is carried on the X chromosome, so women can either have it 1) not at all, 2) on only 1 X (therefore making them a carrier), or 3) on both Xs (exhibiting the trait).
Looking at results, with one X-chromosome, men with the “Warrior Gene” will show a value of 3. Other men will have normal variants: 3.5, 4, 4.5 or 5. With two X-chromosomes, women will have two results. For example, a woman might have 3 and 3, 3 and 5, or 4.5 and 5.
This first example is of a female with one copy of the normal variant and one copy of the Warrior Gene indicated by a value of 3.
In the second example, shown below, this female has the Warrior Gene trait, because she carries the Warrior Gene depletion, shown as a value of 3, on both of her chromosomes, the one contributed to her by her father and the one contributed to her by her mother. This also tells us that her father has the Warrior Gene, since he carries only the X chromosome contributed by his mother, which he gave to his daughter. It also tells us that her mother was either a carrier, if she had only the one copy she gave to her daughter, or had the Warrior Gene herself is she carried two copies.
A male’s results would have only one result listed. If he has a value of 3, he had the Warrior Gene. Any other value is NOT indicative of the Warrior Gene.
Happiness Gene in Women
In an unexpected turn of events, in August 2012, another study in the journal Progress in Neuro-Psychopharmacology & Biological Psychiatry indicates that while this gene may express as aggression in men, it may be the happiness gene in women. Even women with only one copy of the gene were shown to be happier than women who carry no copies. A study of 193 women and 152 men evaluated their happiness level and women who carried this mutation on one or both X chromosomes rated themselves as significantly happier than women who did not carry this trait. There was no difference in the male participants.
Among the many advances and discoveries of modern DNA and genetics are ‘scientific’ oddities. These genetic wonders make it into popular culture and sometimes develop a life there that far outpaces their academic worth. But they are interesting. These factoids are best used as ‘cocktail party conversation’ starters or maybe a good way to tease Uncle Leo at the family picnic. Family Tree DNA, where you can find out if you have the Warrior Gene, portrays it to their customers as just that, a novelty.