Bullies may enjoy watching others in pain

CHICAGO, Nov. 7 (UPI) -- U.S. researchers, using brain scans, have found evidence that unusually aggressive youth may enjoy inflicting pain on others.

University of Chicago researchers said scans of aggressive youths' brains showed that an area associated with rewards was highlighted when the youths watched a video clip of someone inflicting pain on another person. Youths without the unusually aggressive behavior did not have that response, the study showed.

"This is the first time that functional magnetic resonance imaging scans have been used to study situations that could otherwise provoke empathy," Jean Decety said in a statement. "This work will help us better understand ways to work with juveniles inclined to aggression and violence."

The research, published in the journal Biological Psychology, showed that some aggressive youths' natural empathetic impulse may be disrupted in ways that increase aggression, the researchers said.

Researchers compared eight 16- to 18-year-old boys with aggressive conduct disorder to a control group with no unusual signs of aggression.

"Aggressive adolescents showed a specific and very strong activation of the amygdala and ventral striatum -- an area of the brain that responds to feeling rewarded -- when watching pain inflicted on others, which suggested that they enjoyed watching pain," Decety said.