Historically, psychopaths – people who are uncaring about others, extreme risk-takers, and often commit strings of violent crimes – were thought to be mentally disordered.
However, a study led by Queen’s University postdoctoral fellow Daniel Krupp supports more recent thinking, from the perspective of evolutionary psychology, that psychopaths may not be disordered after all. Rather, psychopathy may have evolved to exploit others.
Mental disorders pose an increased risk that people will hurt their kin, but evolutionary theory predicts that mentally healthy people will tend to avoid hurting their genetic relatives. The Queen’s-led study examined 289 cases of violent offenders at a mental health centre in Ontario. Evidence from the study indicates that offenders with a greater degree of psychopathy were actually less likely to hurt their genetic relatives than those with a lesser degree of psychopathy.
“It’s a counterintuitive and surprising finding, considering the impulsive and violent nature of psychopaths, who also engage in ruthlessly selfish behavior,” Dr. Krupp says. “But it makes sense in the light of evolutionary theory: individuals who have evolved to exploit others should nonetheless avoid hurting their relatives, because those relatives also carry copies of their genes.”
The study builds on previous work showing that psychopaths unexpectedly function quite well in society. If they were mentally disordered, we would expect them to have neurological problems, serious disorders like schizophrenia, difficulty interacting with others, problems of physical development, and fewer children.
However, previous studies have shown that psychopaths have normal intelligence, are not likely to have other significant mental issues, are experts at reading and exploiting others, have healthy physical development, and have as many children as others.
Dr. Krupp points out that these findings don’t let psychopaths off the hook for their actions. “That psychopaths don’t suffer from a mental disorder is no excuse. In a sense, they should be considered more responsible for their conduct than someone with a disorder.”
The study was funded by Social Sciences and Humanities Research Council of Canada.
The study is published in the latest issue of Frontiers in Psychology.