Scientists have long known what psychopaths lack: emotions like empathy, fear and remorse. Now, a new study focuses on what they may have — a brain abnormality that may lead them to seek rewards like money, sex or fame at any cost.
Vanderbilt University graduate student Josh Buckholtz tells NPR's Guy Raz that psychopaths have a hyperactive reward system in their brains — the same reward system that drives drug addicts to seek another dose. But first, what exactly is a psychopath?
"We can think of psychopathy as a personality disorder," Buckholtz says. "It's a collection of related traits." Psychopaths are considered superficial, lacking fear, regret or empathy, he says, plus they also exhibit profoundly deviant social behavior.
"What prior research has shown is that psychopaths have changes in their brain ... that are involved in generating emotional experiences," he continues. "We think that these changes in the brain's reward system might promote a focus on reward — on obtaining a reward."
Buckholtz and his team used brain scans to monitor the levels of dopamine — a chemical related to motivation and pleasure — in volunteers' brains during a variety of tests. He found that subjects who'd scored higher in psychopathic traits had correspondingly higher levels of dopamine and greater activity in areas of the brain related to seeking and enjoying rewards.
The correlation might account for the anti-social and aggressive behavior seen in psychopaths. Psychopaths may be so intent on the reward that other concerns — like causing harm or the possibility of punishment — fall by the wayside.
The study used community volunteers who took a test that measured psychopathic traits. "The people in our study might be your Machiavellian mother-in-law, your bullying boss and your conniving co-worker, but none of these people were out there committing violent crimes," Buckholtz says. The results, however, still have relevance for diagnosed psychopaths. Turns out, there may be a little psychopath in all of us.
"Currently, it's thought that psychopathic traits operate along a continuum," Buckholtz says. That means you can measure a range of psychopathic traits in volunteers with no diagnosable psychiatric disorders.
And Buckholtz says that's important, because targeting and treating psychopathic behavior can help reduce crime. "Crime is extremely expensive," he says, "and psychopaths commit more crime than anybody else." And unfortunately, scientists know very little about how to treat psychopathy.
"This might lead the way for future studies that target this system as a way of reducing aggression and anti-social behavior," he says.