Our happy hour fact to amaze your drinking buddies with.

Women prefer men with a "dark triad" of personality traits: narcissism, thrill-seeking and deceitfulness.

In a recent study, researchers gave male college students personality tests and also asked how many women he had slept with. The more a student's personality corresponded to this "dark triad" of traits, the more sexual partners he reported. (Yes, asking a deceitful person questions about sex is tricky, but these results are supported by other research.)

Evolution favors men with these traits, because they are more likely to impregnate a woman, not stick around and then go off and impregnate more women. Since men with this "dark triad" are the most successful breeders, their antisocial personalities continue to persist in humanity's genetic strand.

So if women stopped unlocking their legs for bad boys, not only would you get laid more, but the world would be a safer, humbler and more honest place.