Evolution: Theory or Evidence?

When it comes to evolutionary theories of the mind, I read this the other day that showed a welcome humility about what we know and what we don’t. From Anthony Gottlieb:

Today’s biologists tend to be cautious about labelling any trait an evolutionary adaptation—that is, one that spread through a population because it provided a reproductive advantage. It’s a concept that is easily abused, and often “invoked to resolve problems that do not exist,” the late George Williams, an influential evolutionary biologist, warned. When it comes to studying ourselves, though, such admonitions are hard to heed. So strong is the temptation to explain our minds by evolutionary “Just So Stories,” Stephen Jay Gould argued in 1978, that a lack of hard evidence for them is frequently overlooked (his may well have been the first pejorative use of Kipling’s term). Gould, a Harvard paleontologist and a popular-science writer, who died in 2002, was taking aim mainly at the rising ambitions of sociobiology. He had no argument with its work on bees, wasps, and ants, he said. But linking the behavior of humans to their evolutionary past was fraught with perils, not least because of the difficulty of disentangling culture and biology. Gould saw no prospect that sociobiology would achieve its grandest aim: a “reduction” of the human sciences to Darwinian theory.

This was no straw man. The previous year, Robert Trivers, a founder of the discipline, told Time that, “sooner or later, political science, law, economics, psychology, psychiatry, and anthropology will all be branches of sociobiology.” The sociobiologists believed that the concept of natural selection was a key that would unlock all the sciences of man, by revealing the evolutionary origins of behavior.

The dream has not died. “Homo Mysterious: Evolutionary Puzzles of Human Nature” (Oxford), a new book by David Barash, a professor of psychology and biology at the University of Washington, Seattle, inadvertently illustrates how just-so stories about humanity remain strikingly oversold. As Barash works through the common evolutionary speculations about our sexual behavior, mental abilities, religion, and art, he shows how far we still are from knowing how to talk about the evolution of the mind….

Going by what Barash has to say about religion, Darwinian thinking isn’t likely to transform our understanding of it anytime soon. We do not even know why we are relatively hairless or why we walk on two legs, so finding the origin of religious belief is a tall order. Undaunted, Barash explores various ways in which religion might have been advantageous for early man, or a consequence of some other advantageous trait. It might, for example, have been a by-product of our curiosity about the causes of natural phenomena, or of our desire for social connection. Or maybe religious beliefs and practices helped people coördinate with others and become less selfish, or less lonely and more fulfilled. Although he does not endorse any of these ideas—how could he, given that there’s no possible way to know after all this time?—Barash concludes that it is “highly likely” that religion owes its origin to natural selection. (He does not explain why; this conclusion seems to be an article of faith.) He also thinks that natural selection is probably responsible for religion’s “perseverance,” which suggests that his knowledge of the subject is a century out of date. Historians and social scientists have found quite a lot to say about why faith thrives in some places and periods but not in others—why, for the first time in human history, there are now hundreds of millions of unbelievers, and why religion is little more than vestigial in countries like Denmark and Sweden. It is hard to see what could be added to these accounts by evolutionary stories, even if they were known to be true.