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.