Researchers may soon find a genetic reason for the existence of psychopaths.
By examining DNA samples from New Mexico prisoners, a trio of interdisciplinary researchers at the Duke Institute for Brain Sciences think they might be able to understand what causes some people to lack empathy. Psychopaths have a personality disorder characterized by antisocial behavior—most notably a lack of empathy. They commit 30 percent of violent crimes, even though they account for less than 1 percent of the population, said Walter Sinnott-Armstrong, Chauncey Stillman professor of practical ethics and member of the research team.
“[Psychopaths] represent a profound philosophical problem about the limits of human nature and morality,” Sinnott-Armstrong said. “If we can treat that 1 percent, we can have a big impact on society because we would also be preventing the worst kinds of crime.”
Finding a genetic cause for psychopathy could help researchers find ways to better treat the disorder, especially if the research shows what parts of a person’s life could have triggered psychopathic behavior, said Pate Skene, associate professor of neurobiology and member of the research team.
“Evidence that psychopaths have certain triggers that can make them vulnerable to developing psychopathic behavior may be helpful in determining help, treatment and support for them,” Skene said.
Gaining a better understanding of psychopaths could also lead to a variety of legal implications— ranging from assessing prisoners’ rehabilitation to determining the ability of a defendant to stand trial, the researchers noted.
Psychopaths tend to be more charming and able to manipulate their way out of prison, and then they return to previous behaviors when released, said Liz Cirulli, assistant professor at the Duke Center for Human Genome Variation, who was added to the team to examine the DNA samples.
“We need a better way to determine who will recidivate when they get out of prison,” he said.
Finding a genetic cause for psychopaths could potentially lead some courts to re-examine the definition of an insanity plea in a trial. Now, a person can only use an insanity defense if he or she did not understand that they were committing a crime, which is not the case for psychopaths, Skene said.
“Psychopathy is not an acceptable reason for an insanity plea because they know what the law is, but they don’t care,” Skene added. “[Understanding] empathy is helpful in determining how we will handle such people.”
The study will examine research collected by a lab at the University of New Mexico headed by Kent Kiehl, associate professor of psychology. The study will also examine gene samples from samples from more than 1,000 Duke students and employees, as well as people in the Durham community from the past three years.