Bad guys really do get the most girls:

But being just slightly evil could have an upside: a prolific sex life, says Peter Jonason at New Mexico State University in Las Cruces. "We have some evidence that the three traits are really the same thing and may represent a successful evolutionary strategy."
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This observation seems to hold across cultures. David Schmitt of Bradley University in Peoria, Illinois, presented preliminary results at the same meeting from a survey of more than 35,000 people in 57 countries. He found a similar link between the dark triad and reproductive success in men. "It is universal across cultures for high dark triad scorers to be more active in short-term mating," Schmitt says. "They are more likely to try and poach other people's partners for a brief affair."
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"They still have to explain why it hasn't spread to everyone," says Matthew Keller of the University of Colorado in Boulder. "There must be some cost of the traits." One possibility, both Keller and Jonason suggest, is that the strategy is most successful when dark triad personalities are rare. Otherwise, others would become more wary and guarded.

Frequency dependence. Control for environment and one might assume that personality morphs will hit an equilibrium in terms of relative proportion; but of course one assumes that any normal environment will be subject to exogenous shocks which jar the equilibrium on a regular basis. I wish popular science articles would bring up Hawk vs. Dove dynamics more often to introduce the general concept of variant strategies in populations. The relevance of this sort of result to recent posts should be pretty obvious, and is also one reason many people were always less than enthusiastic about Evolutionary Psychology's monomaniacal focus on human universals.

Labels: Behavior Genetics