THE EVOLUTION OF HUMAN BEHAVIOR AND “JUST-SO STORIES”

Darwin's claim is probably guilty of pardonable exaggeration. After all he did not prove the origin of man, and Locke's greatest contributions were to political philosophy, not metaphysics. But it may turn out that Darwin's twentieth-century grandchild, genomics, vindicates this claim with respect to both metaphysics and political philosophy. Here I focus on the latter claim alone, however.

From the year that William Hamilton first introduced the concept of inclusive fitness and the mechanism of kin selection, biologists, psychologists, game theorists, philosophers, and others have been adding details to answer the question of how altruism is possible as a biological disposition. We now have a fairly well-articulated story of how we could have gotten from there, nature red in tooth and claw, to here, an almost universal commitment to morality. That is, there is now a scenario showing how a lineage of organisms selected for maximizing genetic representation in subsequent generations could come eventually to be composed of cooperating creatures. Establishing this bare possibility was an important turning point for biological anthropology, for human sociobiology, and for evolutionary psychology. Prior to Hamilton's breakthrough it was intellectually permissible to write off Darwinism as irrelevant to distinctively human behavior and human institutions.