Scans Show Psychopaths Have Less Brain Matter In Regions Tied To Empathy

Psychopaths exhibit structural differences in their brains compared to the general population, according to a new study—an insight that could prove crucial in better understanding and potentially treating the condition, David Nield reported for ScienceAlert.

On average, the brains of psychopathic individuals were about 1.45% smaller than those of the control group.

The research, led by scientists from the Research Center Jülich and RWTH Aachen University in Germany, compared brain scans of men diagnosed as psychopaths with scans from healthy male volunteers.

“Psychopathy is one of the greatest risk factors for serious and persistent violence,” the researchers wrote in their published paper.

“To identify its neurobiological underpinnings, we examined 39 male psychopathic subjects and matched controls using structural magnetic resonance imaging and the Psychopathy Check-List (PCL-R).”

The PCL-R combines interview responses with professional assessments and official records to generate three scores: an overall score, a Factor 1 score measuring interpersonal and emotional traits, and a Factor 2 score assessing impulsive and antisocial behavior.

While only minor structural brain differences correlated with Factor 1 scores, more substantial changes were observed in individuals who scored high on Factor 2.

These included reduced volume in the pons (a part of the brainstem), the thalamus, the basal ganglia, and the insular cortex—regions associated with involuntary actions, emotional processing, sensory interpretation, motivation, and decision-making.

In short, these brain areas play a critical role in how people respond to their environments. On average, the brains of psychopathic individuals were about 1.45% smaller than those of the control group.