Understanding Psychopathic and Sadistic Minds

Psychopathic serial killers are a source of infinite public fascination. If best-selling novels, hit TV series and popular films are any indication, you’d think real-life Hannibal Lecters were constantly running amok in the U.S. Thankfully, such offenders are far less prevalent in reality than they are in entertainment — but the disproportionate damage done by violent and even nonviolent psychopaths not surprisingly attracts intense scientific interest as well. On May 11, in fact, the New York Times explored whether psychopaths can be diagnosed as young as age 9.

Another way to figure out what makes the psychopath tick is to contrast him — and they are overwhelmingly male — with other abnormal personalities. In a recent study led by Jean Decety, a professor of psychology and psychiatry at the University of Chicago, researchers looked at a personality trait often confused with psychopathy: sexual sadism.

The Psychopath vs. the Sadist


The typical Hollywood serial killer combines psychopathic traits — cold calculation, lack of empathy, delight in manipulation — with the sadist’s joy and erotic pleasure gleaned from the pain of others. But in reality, these traits may be quite distinct. “If you look at movies, there are people that are both — like Hannibal Lecter,” says Decety. “I’m not sure that’s what we have in the real world.”


Decety and his colleagues recently published a brain-scan study of 15 violent sexual offenders, eight of whom were classified as sexual sadists. The research deliberately excluded psychopaths in order to find brain differences unique to sadism.


Participants were shown images that involved either pain or no pain — for example, a picture of a person stabbing a table or another person’s hand with scissors, or an image of someone slamming a car door and either hitting or not hitting another person.


When viewing the pictures of pain, the sadists showed greater activation in their amygdala — a brain area associated with strong emotion — compared with the other sexual offenders. Moreover, the sadists rated the pain experienced by the victim as more intense than the nonsadists did. And the more intense the sadists thought the pain was, the greater their activation in another brain region called the insula, which is involved with monitoring one’s own feelings and body states.



“When you feel something like disgust, pain, pleasure, even orgasm, the insula plays a critical role to bring those bodily emotions to awareness,” Decety says.


Decety’s study suggests that sadists seem to be especially tuned in to what their victims are feeling — in fact, they experience it vicariously and are aroused by it. Psychopaths, on the other hand, tend to be indifferent to the emotions of others. “If you live with a psychopath and you cry because that person was unpleasant to you, that probably doesn’t matter to him. He is not moved and doesn’t care, because he doesn’t feel anything about what you feel,” says Decety. “The sadists do feel. They understand that the victim is in pain.”