Photo: UBCO

New research from the University of British Columbia Okanagan shines a light on the sometimes violent behaviour of psychopaths.

The new research published in the Journal of Personality Disorders, shows that psychopaths may have a decreased ability to even sense someone else’s pain, according to postdoctoral fellow in psychology at UBCO, Dr. Kimberley Kaseweter.

“A lot of the literature has focused on those basic emotions and psychopathy, like anger, fear and sadness,” says Dr. Kaseweter. “Almost no research has really focused on pain, which I found surprising because of the association between pain and violent behaviour.”

Study participants completed the Self-Report Psychopathy Scale to assess psychopathic traits within four different facets: callous affect, interpersonal manipulation, antisocial behaviour and erratic lifestyle. They also watched video recordings of patients manipulating injured shoulders in range-of-motion tests and then rated both the intensity and unpleasantness of the pain from patients’ facial expressions.

These recordings from actual patients showed spontaneous, natural expressions of pain that had been intensely coded frame by frame. The patients also self-reported their pain from these manipulations.

Dr. Kaseweter studied whether psychopathic traits were connected to differences in how these participants might perceive others’ pain.

“We were able to break those two factors apart and tease that apart, which I think really gets at answering our questions. Do individuals who were high in psychopathic traits have an inability to see the facial expression of pain? Or if they can actually see it and just don’t care,” she says.

The study found that people with psychopathic traits have a reduced sensitivity to other people's pain—they were significantly less accurate in their ratings of pain in other people’s facial expressions.

While the study findings may not be surprising the results showed that one possible mechanism might be a reduced ability to see other people’s pain.

“If they’re not accurately perceiving those facial expressions, they’d be missing the ability to identify that expression and then feel empathy and pull away from that violent behaviour,” says Dr. Kaseweter.

“I think it’s a very important distinction. So how do we help? Is it just that people high in psychopathic traits don’t care? Then we have to teach them empathy in a different way. Or is it that they’re not seeing facial expressions accurately? Our findings suggest the latter—and that this decreased ability to detect pain accurately may underlie the lack of empathy we see with psychopathy.

“If this is the case, then training interventions designed to improve pain detection may, in turn, reduce the callous affect and antisocial behaviour characterizing psychopathy.”

Dr. Kaseweter is hopeful the study could help isolate an area to direct more successful treatment in the future.

Psychopaths have high rates of criminal behaviour, current rehabilitation efforts have been largely ineffective, if not completely counterproductive.