School Bullies – Is the Amygdala to Blame?

Countless studies have focused on the subject of bullying, and the latest even suggest an interesting paradox: is bullying caused by a lack of empathy for others or, surprisingly, by too much empathy? Because, although all of us react in some way to seeing others in pain, we don’t all react in the same way. Scientists are asking, could an empathic response to others in pain cause enough emotional distress in some adolescents to actually cause them to respond aggressively? Here lie the two big hypotheses and they’re rather contradictory.

A recently published University of Chicago study tested the response from two different groups of adolescents to viewing others in pain. One group had been previously diagnosed with CD, a mental disorder associated with increased risk of incarceration, injury, depression, homicide, and an overall disregard for rules and laws; the other group was an asymptomatic control group. The teens were exposed to various stimuli, which showed individuals in accidental pain and individuals in pain that was intentionally caused by another, in a functional MRI (fMRI) scanner.

The results of the fMRI testing showed that in both groups, the “pain matrix” was selectively activated during the accidental sequences. But, the patterns of activation during the pain-caused-by-other sequences varied significantly between the two groups. Three specific regions, the amygdala, striatum, and temporal poles were activated in the aggressive group, but not the control. Contrary to previous studies, bullies may actually exhibit a greater than average neural response to those in pain.

As for the amygdala, a crucial player in the formation of emotional reactions, its degree of activation was positively correlated to the number of aggressive acts of the participants in the study leading scientists think to that the activity in the amygdala, coupled with the striatum, creates a positive response for those aggressive youth: pleasure.

The researchers called this finding “intriguing” but we’re still far from understanding the complex nature of aggressive responses and why bullies bully. At least we know violent TV isn’t all to blame.

Reference

J DECETY, K MICHALSKA, Y AKITSUKI, B LAHEY (2008). Atypical empathic responses in adolescents with aggressive conduct disorder: A functional MRI investigation Biological Psychology DOI: 10.1016/j.biopsycho.2008.09.004