Psychopathic Children Show Suppression to Others' Pain, Brain Scan Reveals Aggression

A new study reveals that some children with severe behavioral problems show a suppressed response to others' pain.

Researchers studied brain scans of children with conduct disorders, which is marked by aggression, cruelty to others and anti-social behavior. Some kids with conduct disorders also display what psychologists refer to as "callous-unemotional traits," which means they lack guilt or empathy, all together.

The patterns seen in these children's brains may reveal a vulnerability to psychopathy in adulthood.

"Brain-imaging data indicate that the brain regions that seem disrupted in adults with psychopathy are also functioning in an atypical fashion in children with conduct problems and callous, unemotional traits," said study researcher Essi Viding, a professor of developmental psychopathology at University College London, according to Live Science.

Researchers asked boys ages 10 to 16 with a conduct disorder to look at pictures of hands and feet of those in painful situations and non-painful ones while undergoing functional magnetic resonance imaging (fMRI), a technique the provides a measure of blood flow to various regions of the brain. The more active the region, the more blood that rushed to that spot.

The painful situations showed photos such as a knife about to slice into a hand, or a foot being jammed in a door. The non-painful scenarios included the same elements but without the "ouch" effect. A hand might be shown next to a knife, for example. 

The researchers focused on several brain areas known to play a role in empathy, including the anterior insula, which sits deep in the brain; the anterior cingulated cortex, a deep layer that sits behind the forehead; and the inferior frontal gyrus, a ridge of brain matter on the frontal lobe.

In all three regions, kids with conduct problems showed reduced brain activity when viewing images of pain compared with the healthy kids. The children were matched on age, IQ, socioeconomic status and ethnicity to reduce the chance of unrelated factors skewing the results. 

What's more, not every child with a conduct problem reacted the same way, and so, researchers caution that these findings in no way suggest that those with conduct problems will be psychopaths as adults.

"It may be that these children have atypical arousal response to pain - for example, those children who are most callous may not feel pain as keenly as their peers, and this may, in turn, mean that they find observing pain less distressing than their peers," Viding said. "This is just one possibility that needs to be explored further."

The findings for the study can be found in the journal Current Biology.