You're driving on the highway and suddenly a car comes whipping out of the lane next to you, forcing you to slam on the brakes. Do you think, "Oh well, the driver must be in hurry"? Or do you flash him a strategic hand gesture and scream some choice phrases?
You might be interested to learn that your reaction may be connected to your DNA.
A recent study co-authored by Professor of Political Science Rose McDermott examines a genetic link to aggression. McDermott is interested in political psychology and over the past decade has been studying aggression through simulated war games.
Sex differences accounted for the most robust distinctions in behavior, McDermott said, but the discrepancy was not due to hormonal differences between the populations. It was "clear something else was going on," McDermott said. This led to her search for a genetic component to aggression.
She set up a experiment in which subjects completed a vocabulary task in order to earn virtual money. They then were told that an anonymous person could choose to take some of the money from them, but that they had the option of punishing this person for doing so by making him eat hot sauce. In order to administer the punishment, though, the subjects had to pay even more money than they originally lost. The subjects thought they were retaliating against the other person, but in reality the "other person" was a computer program, which always took either 20 or 80 percent of the person's earnings.
What was significant about the findings was that individuals with a certain gene were much more likely to administer punishment when 80 percent of their earnings were taken compared to people without the gene. The findings seem to indicate that, under conditions of high provocation, individuals with this gene are more likely to show aggressive behaviors.
All of the subjects for this study were male because the gene is on the X chromosome - since men only have one X chromosome, it was simpler to determine if a man had an active copy of the gene.
McDermott decided to look at this particular gene because it had been linked to aggression in primates and was found to be more prevalent in certain populations that have historically had a large focus on warfare. These findings collectively have led to the name "warrior gene."
This is not the only study that has tried to connect complex behaviors to genetic factors. Other recent studies have found genetic links to trust and mate selection, McDermott said.
Like other human behaviors, aggression is a "very, very complicated phenomenon" that is influenced by genetic, social and environmental factors, McDermott said. Her goal "is to understand more about it at a basic scientific level," she said. "I'm planning to explore further the relationship between genetic and environmental triggers." Specifically, she would like to study the effects of traumatic early life events on aggressive behavior, she said.
Visiting Assistant Professor of Psychology Theresa Didonato, who teaches a course on social psychology, agreed that it is important to consider the many factors that influence complex behaviors such as aggression. "I wouldn't want (McDermott's) results to be misinterpreted (as saying) that you are locked in," she said, referring to individuals being genetically predestined for aggressive behavior. "Genes are not deterministic."
