If you saw a man walk into a bar with a John Wayne swagger, you might assume that he’s a confident, tough kind of guy. Or perhaps you’d have less polite thoughts. Either way, you probably wouldn’t be able to help yourself from jumping to conclusions about his personality based on his gait.

Psychologists have been studying these assumptions for well over three quarters of a century, and their findings suggest that most of us do tend to make very similar interpretations of other people’s personalities based on their walking style. After watching that wannabe cowboy walk into the bar, the likelihood is that you and I would agree about the kind of personality he has.

But how accurate are these assumptions? And what other kinds of characteristics can we read from someone’s gait? Chillingly, the best person to ask may be a psychopath.