Psychopathy affects around one in 100 people, meaning most of us will encounter a psychopath at some point. Researchers have now identified five telltale behaviours that may indicate psychopathic traits.
One sign is a lack of contagious yawning. A 2015 study at Baylor University found that individuals who scored highly on cold-heartedness were less likely to yawn in response to seeing someone else yawn, a phenomenon linked to empathy.
Psychopaths also tend to be night owls. Dr Kathryn Smerling noted they often have difficulty sleeping and are generally nocturnal. Research from the University of Sydney on 263 students found that those who stayed up late were more likely to display antisocial traits like narcissism and psychopathy.
Another clue is the use of beat hand gestures—up-and-down or back-and-forth movements that emphasise speech. In a 1998 analysis of videotaped interviews, psychopaths used more of these gestures than non-psychopaths. Conversely, they tend to keep their heads still while talking, according to a University of New Mexico study of inmates.
Finally, psychopaths frequently discuss food, money, and sex, as found by researchers at Cornell University. These three topics are overrepresented in their conversations.
