Bullies appear to enjoy seeing other people in pain, Reuters reports. Researchers in Chicago took brain scans of two sample groups of teens while showing them videos of one person hurting another. When showed violence, one group of teens, who were diagnosed with aggressive-conduct disorder and had recently attacked schoolmates, had consistent activity in the brain’s reward centers.
The other group, with no history of aggression, instead has activity in the medial prefrontal cortex—an area associated with self-regulation that is conspicuously inactive in the “bully” group. “It is entirely possible their brains are lighting in the way they are because they experience seeing pain in others as exciting and fun and pleasurable,” said one researcher.