The science behind why you sometimes end up dating terrible people

Flickr/Morgan People who score highly in the Dark Triad personality traits – narcissism, psychopathy and Machiavellianism – are vain, selfish, callous and manipulative. They're not the kind of people you want to spend much time with. This raises the obvious question – to put it bluntly, why over evolutionary timescales haven't these people died out? One possibility is that their traits actually confer short-term advantages in the mating game. Dark Triad people are obnoxious once you get to...