Reading time: 70 seconds – Canadian researchers at the University of British Columbia, asked 1084 heterosexual men and women to rate the sexual attractiveness of people of the opposite sex based on a photo. The study, published online in May, 2011 in the American Psychological Association journal Emotion, adds fuel to the notion that women are attracted to bad boys and men to movie stars.

“Women find happy men less sexually attractive than those with expressions of pride or hint that they have done wrong and know it,” says Jessica Tracy the who led the study. The men’s reaction was just the opposite. “Women who smile are absolutely very attractive. That was by far the most attractive expression women showed.”

OK. But lets get real here. This is all fine for first impressions, and in short bursts, but the reality is that men who spend too much time brooding and women who can’t stop smiling are scary and confusing. They are right up there with too much eye contact and people who don’t let go of your hand after a handshake.

But , what the heck. Give it a shot. Guys, want to look sexy and get the girl? Don’t smile too much and look broody. Women, want to be found sexually attractive? Smile lots.