for National Geographic News
The brains of bullies—kids who start fights, tell lies, and break stuff with glee—may be wired to feel pleasure when watching others suffer pain, according to a new brain scanning study.
The finding was unexpected, noted Benjamin Lahey, a psychologist at the University of Chicago and co-author of the study, which appears in the new issue of the journal Biological Psychology. Jean Decety, a neuroscientist at the University of Chicago, is lead author of the study.
The researchers had expected that the bullies would show no response when they witnessed pain in somebody else—that they experience a sort of emotional coldness that allows them to steal milk money with no remorse, for example.
Previous research had shown that when nonbullies see other people in pain, the same areas of the brain light up that do when the nonbullies themselves experience pain—a sign of empathy, Lahey said.
The new research showed these areas in the bullies' brains were even more active than in the nonbullies.
But the bullies' empathetic response seemed to be warped by activity in the amygdala and ventral striatum, regions of the brain sometimes associated with reward and pleasure.
"We think it means that they like seeing people in pain," Lahey said.
"If that is true," he added, "they are getting positively reinforced every time they bully and are aggressive to other people."
(Related: "'Brain Reading' Device Can Predict What People See [March 5, 2008].)
In the study, Lahey and his colleagues looked at brain activity of eight 16- to 18-year-old boys with histories of lying, stealing, committing vandalism, and bullying.
These eight boys, who suffer what's clinically known as aggressive conduct disorder, were compared to a group of adolescent boys with no such histories.
The bullying group was shown a series of brief videos that depict painful situations—some accidental, such as a hammer dropped on a toe; others intentional, such as a piano lid closed on a player's fingers.
In addition to revealing activity in pleasure- and pain-related areas of the brain, the scans also showed that a portion of the brain that helps regulate emotion is inactive in bullies.
In other words, bullies lack a mechanism to keep themselves in check when, for example, a kid accidentally bumps them in the lunch line.
"We will have to develop therapies to either treat or compensate for this lack of self-regulation that we think is there and the fact that it may be positively reinforcing every time they hurt somebody," Lahey said.
"I am not surprised that scientists who are working on this and doing brain imaging are finding more and more," said Marlene Snyder of Clemson University's Institute on Family and Neighborhood Life and the Olweus Bullying Prevention Program.
"I think we're just at the beginning of pioneering understanding how the brain works," she said.
"The more we know about this, the more hopeful we can all be in finding meaningful interventions."
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