People with psychopathic tendencies—who may constitute upwards of 15 percent of prison populations—poorly activate parts of the brain responsible for empathy, according to a study in the April 24 JAMA Psychiatry online. While control subjects cringe when they see a person in pain, as when getting a hand slammed in a car door, prisoners who scored high on a test for psychopathy demonstrated little empathy. Functional magnetic resonance imaging of the brain indicated that those individuals also had subpar function in the orbital frontal circuit, which helps process emotions. Notably, some of the same brain areas are compromised in frontotemporal dementia (FTD). People with FTD may flout social norms and land in hot water. However, study senior author Kent Kiehl of the University of New Mexico in Albuquerque said he has seen no evidence that people with FTD are more likely to end up in the prison system as those with psychopathy are prone to do.
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