Art and Sexual Selection

Followers of evolutionary psychology have marveled in the last few years on the capacity of this discipline to throw new light on aspects of human life, both the obvious and the curious. The Swiss Army Knife metaphor of the mind as a multipurpose instrument fitted by evolution to solve Pleistocene problems with natural ease has great attractiveness. It offers a significantly more powerful way to view our specialized mental capacities than the older model that tries to see us as creatures with general abilities to learn whatever parents or society teach us. We're not usually as motivated to learn the calculus, or as adept at it, as we are in figuring out who's sleeping with whom in the neighborhood, and these differential interests and capacities are not socially constructed. Striking empirical findings, such as the statistic that a small child or infant is roughly a hundred times more likely to die at the hands of a stepfather than at the hands of a biological father, defy explanation in terms cultural imperatives but are consistent with evolutionary psychology and explained by it. And persistent average sex differences, like the superior detail noticing capacities of women and the better map-reading abilities of men, nicely fit with evolutionary psychology's account of Pleistocene adaptations.

In developing their approach, evolutionary psychologists tend everywhere to see the hand of natural selection in features of the mind. Steven Pinker, for instance, argues that we are adapted "for causal and probabilistic reasoning about plants, animals, objects, and people." We had to be clever problem-solvers in the Pleistocene, dealing with the practical challenges thrown up by that environment. The mind on this view evolved in response to demands for survival. Even such apparently unproductive characteristics of homo sapiens as an interest in, say, imaginative story-telling, singing, or cave-painting, require that we posit some kind of survival advantage advanced by these behaviors.

This is the Darwinism we all know, and while its central mechanism of natural selection has proven to be one of the most versatile and powerful explanatory ideas in all of science, there is another, lesser known side to Darwin, the central source for which is his last book, The Descent of Man and Selection in Relation to Sex, to give its complete title. In this monumental work, Darwin discusses the other great driving force of evolution, sexual selection. The most famous example of sexual selection is the peacock's tail. This huge display, far from enhancing survival in the wild, makes peacocks more prone to predation. The tails are heavy, and require lots of energy to grow and to drag around. And therein, oddly, lies nature's point: simply being able to manage with a tail like that functions as an advertisement to peahens: "Look at what a strong, healthy, fit peacock I am." For discriminating peahens, the tail is a fitness indicator, and they will choose to mate with peacocks who display the grandest tails.

Fundamental to sexual selection in the animal kingdom is female choice, as the typical routine for most species has males displaying strength, cleverness, and general genetic fitness in order to invite female participation in producing the next generation. With the human animal, there is a greater mutuality of choice, although even with us it is often males who propose and females who dispose. This is one of the central ideas of The Mating Mind: How Sexual Choice Shaped the Evolution of Human Nature, by Geoffrey Miller (Doubleday, $27.50). Miller holds that the source of the traits we tend to find the most endearingly human--qualities of character, talent, and demeanor--have come to be built into our character during a million years in which women and men chose sexual partners. We can see striking examples of human sexual selection at work even in recent, historic times. The Wodaabe of Nigeria and Niger are beloved by travel photographers because of their geere wol festivals, where young men make themselves up (in...