The heritability of fitness : does mate choice favor good genes ?

marry? How do we perceive someone as beautiful or exciting? In the last few years, research into these questions has been revolutionized by a surprising marriage of evolutionary and cognitive perspectives. Mate choice research now uses evolutionary theory as the explicit functional framework for understanding human sexual psychology1–7. At the same time, it is implicitly guided by the ‘computational sufficiency’ principle of cognitive science, that psychological models should aim to be computationally specific enough to reproduce the behavior being modelled8,9. These Darwinian and cognitive revolutions have produced a renaissance in mate choice research, a topic that now dominates both human evolutionary psychology and animal behavior studies in other species10. Until a decade ago, research on human mate choice was limited mostly to social psychology studies on ‘interpersonal attraction’11, sex research interviews and cultural anthropology. Social cognition research in particular tended to view sexual attraction as an outcome of arbitrary, poorly defined factors such as proximity, similarity, salience and stereotypes that distort domain-general social attribution mechanisms12. Recently, mate choice has become dominated by evolutionary psychology, which takes a functional, cross-cultural, domain-specific approach to understanding the adaptive goals of mate choice. Evolutionary psychologists search for ‘mental adaptations’, complex mechanisms that have been shaped over millennia of natural selection and sexual selection to solve the survival and reproduction problems that faced our hunter-gatherer hominid ancestors in Pleistocene Africa13,14. Through the influence of cognitive science, these adaptations are typically viewed as intricate software designed by evolution, specialized to process naturally occurring information about biologically important situations in ways that guide adaptive behavior9. Thus, evolutionary psychologists tend to analyze mate choice in terms of the structure of the environment outside the decision-maker (including observable cues and hidden traits of potential mates, and features of the local mating system), and the types of perception, computation, inference, search, utility functions, decision policies, strategies and signals that the decision-maker uses3,4,6,9,15.