Study Links The Brain To Aggressive Behavior

Nov 30, 2017

Social scientists say children who are physically abused are more likely to be abusive themselves as adults, but research at Virginia Commonwealth University suggests another factor in people who are violent.  Their brains are downright different.  

Doctoral students Emily Lasko, Sam West and Alexandra Martelli join Assistant Professor David Chester in the lab at Virginia Commonwealth University to study aggression and the brain.
Credit Virginia Commonwealth University

David Chester has long wondered about people who are cruel or violent. “Hurting other people always seemed like such a strange, paradoxical thing to do," he explains. "You’re trying to get along in the world.  Why would you hurt other people?  And I was wondering why we’ve advanced so far as a species and a society, and yet we’re still plagued by these violent tendencies.”

So, as a professor of psychology at Virginia Commonwealth University, he set out to answer that question.  He and his colleagues put study subjects in an MRI machine, so they could watch brain activity as study subjects played a violent video game against a virtual opponent. 

“They’re competing against this individual, and there’s a kind of punishment they have in the task," he explains. "You can get blasted with this horrible noise that sounds like a cat getting sucked into a jet turbine, and they can pick the volume of that noise for their opponent, and that’s our way of measuring aggressive behavior.”

In the most aggressive people, they saw something surprising.

“The extent to which they retaliate against this person – try and hurt them, tracks with the extent to which the reward circuit in the brain is activated, and it’s also activated by painkillers and pictures of adorable animals – the pleasure centers of the brain, and it really suggests a psychological process whereby the act of revenge can be truly a pleasant one,” Chester says.

The good news, he says, is that even with a biological tendency, people can be trained to control their violent conduct.  What’s more, medications used to treat alcoholism by blunting the positive feelings associated with drinking could also be used with people who can’t get a grip on their aggressive behavior.