Every attempt to bring an understanding of evolutionary history to bear on questions of human behavior eventually runs up against the problem, the undeniable fact, of the extreme flexibility of human behavior. More than any other species, it would seem, human beings have the ability to overcome virtually any behavioral tendency with which evolution, in the current guise of “human nature”, supplies us. For those who reserve a special place for humanity outside of (or above) the animal kingdom, our ability to learn, to overcome our animal heritage, is proof enough that there is more to us than mere biology can explain; more than for which the nearly three-billion-year history of genetic evolution can account.

Even if we feel it is a mistake to try and understand human beings in isolation, as a species unto itself that follows unique rules and procedures, still one must admit that the flexibility of human nature presents a problem. What exactly is the importance of evolutionary history for a species that can apparently learn (or unlearn) anything, other than that history has supplied us with the ability to learn and some tendencies that can be overcome? If our nature is such as to make us so nearly entirely creatures of nurture, then isn't the essential story about what people actually do a story about our developmental environments, our life histories, our culture, and its history?