How much can we really know about a person just by a quick glance at their face? Quite a bit, recent research suggests, showing we are able to accurate assess others’ personality traits, their likelihood of cheating on an economic game or how much they like children ( if they’re men) just by looking at pictures of their faces. And the list is getting longer.

A recent paper in Psych Science showed that facial structure is a reliable cue for revealing aggressive tendencies in men. The study had participants look at pictures of male faces and rate them for aggression (the men pictured had previously engaged in a task that measured their tendency to behave aggressively).* Both the participants ratings and the men’s facial width to height ratios significantly predicted aggressive behavior. And mama always told me not to judge a book by its cover. Might have to start rethinking that bit of advice.

*Aggression ratings were positively correlated with masculinity and dominance, and negatively correlated with trustworthiness and attractiveness.