My TLS review of Darwin’s Cathedral

As promised, here’s my old review of David Sloan Wilson’s book, Darwin’s Cathedral, which criticizes the theory of “cultural group selection” for the spread of religion mentioned in the last post. The full reference is below (there may be slight differences between what was published and the version I give here, which was the submitted version; I have no access to the online version nor possess a pdf file of what was published).

Coyne, J. A. 2002. They shall have their rewards on earth, too. (Review of Darwin’s Cathedral by D. S. Wilson). Times Literary Supplement, London. Nov. 1, 2002, p. 31.

*******

They Shall Have Their Rewards on Earth, Too

Jerry Coyne

David Sloan Wilson
Darwin’s Cathedral: Evolution, Religion, and the Nature of Society
268 pp. University of Chicago Press. £17.50
__________________________________________________________________

Altruism may be a boon to society, but it’s a problem for Darwinism. “Unselfish genes” causing true biological altruism, in which an individual sacrifices its own reproductive success for the benefit of others, should in theory be eliminated by natural selection. Yet such altruism seems to occur. Many songbirds, for example, give special alarm calls when a predator appears. These warn the flock, but may make the caller especially visible and vulnerable to attack.

One biological explanation is “group selection,” a form of natural selection entailing differential success of groups rather than individuals. An alarm-calling bird may be at a relative disadvantage, but groups of birds containing many callers enjoy lower predation. Such groups can thus proliferate, spreading genes for alarm-calling.

One of the pioneers of this theory is David Sloan Wilson, an evolutionist at the State University of New York. In Darwin’s Cathedral, a thoughtful and provocative work, Wilson turns his spotlight on religion, which, he claims, can be explained only by group selection.

According to Wilson, a religion is the human equivalent of a pack of lions: by cooperating as a group, people attain benefits beyond their reach as individuals. By “benefits,” Wilson does not mean spiritual or psychic rewards, but purely material ones: food, prosperity, and health. As first proposed by Durkheim, religions are therefore vehicles of “secular utility.” Early Christians, for example, nursed each other through plagues, and were more likely to survive than their non-nurturing pagan neighbors. Balinese religion enforces an intricate system of irrigation to ensure an egalitarian distribution of water. In the US, Korean Christian churches provide recent immigrants with homes, jobs, and money.

Many scholars have similarly emphasized the social aspects of religion, but where does group selection enter the equation? Wilson’s explanation is subtle, expressed most clearly in a footnote: “Group selection has been a very important force, but not the only force, in the cultural evolution of religions and in the genetic evolution of the psychological mechanisms relevant to religious beliefs and practices”. His argument thus involves both cultural and genetic evolution.

Cultural evolution is simply the spread of beliefs or practices through assimilation. Such evolution differs from genetic evolution in two important ways. While genes spread only from parent to offspring (‘vertically”), cultural traits can also spread “horizontally”: in the case of religion, by imitation, conversion, or conquest—processes much faster than the spread of genes. Second, while genetic evolution depends on a single criterion of fitness—the number of offspring produced by the carrier of a gene—cultural traits spread by many different psychological and cultural mechanisms. The forces responsible for the spread of Marxism differ from those causing the success of Madonna.

Wilson believes that all successful religions share critical attributes. These include psychological altruism (helping others in a way that may reduce your well-being), codified egalitarianism (so that nobody feels he’s getting a raw deal), policing practices (to prevent cheaters from reaping benefits without paying costs), and conduct-regulating edicts such as the Ten Commandments (morality enforces group harmony). Spiritual symbolism, the defining feature of religion, is to Wilson merely an emotional lever for obtaining goods: “Even massively fictitious beliefs can be adaptive, as long as they motivate behaviors that are adaptive in the real world.” Stories such as Christ’s crucifixion can arouse emotions that secure group benefits. Because the most persistent and widespread faiths are those whose principles provide the greatest material benefits for adherents, religions are products of group selection.

This idea has some merit. Most religious communities function as social units, improving the lot of at least some members. And group attributes clearly affect the success of religions. The Shaker policy of renouncing reproduction obviously contributed to its demise. In early Christianity, women enjoyed high status, which lured low-status women from surrounding communities, who in turn brought male converts and thus Christian children. But Wilson’s emphasis on the predominance of group selection, which he preaches relentlessly, suffers from problems.

One difficulty is that some popular religions have tenets that are not good for everyone, and also spread by processes other than group selection. Hinduism, for example, codifies inequality via the caste system. It is hard to see what material benefits were enjoyed by the oppressed untouchables, many of whom fled to other faiths. Much of Hinduism can be understood only as a historical relic of Aryan invasion and the subjugation of the vanquished, as well as the perpetuation of cultural control by the promise of nonmaterial benefits—a rise in status in the next incarnation. Similarly, the spread of religions in post-Reformation Europe followed the principle of cuius regio, eius religio: people adopted a faith not because of its rewards, but because it was practiced by their ruler. As Wilson admits, “the factors that cause one social experiment to succeed while others fail are probably so complex and historically contingent that they will never be fully understood, and they certainly extend beyond the conscious intention of the individual actors.”

Wilson’s views also suffer from a posteriori-ism: one can always make up a story about why a religion’s success was due to group utility. This makes the theory nearly unfalsifiable. He attributes the persistence of the Jews, for example, to their reluctance to accept converts, making Judaism a “cultural fortress” and forcing new members to demonstrate strong commitment. But the success of Christianity and Mormonism is attributed to the opposite trait: their ready acceptance of converts!

Finally, as Wilson admits, his theory of cultural group selection also applies to non-religious social groups, from Freemasons to Marxists, which rest on emotional symbols and supposed benefits to members. Thus his is a theory of cooperation, not of religion. He fails to address the essence of religion—whatever it is that sets, say, Catholicism apart from Rotary Clubs. Rates of martyrdom are higher among Catholics than among Rotarians. Understanding the root of this difference would reveal the essence of religion, but here Wilson has nothing to offer.

The problems become more severe when Wilson turns to genetic evolution. He claims that religion rests on aspects of human nature that evolved by group selection. These “genetic” traits include conformity, docility, sociality, a yearning for respect, a capacity for symbolic thought, the desire to root out cheaters, and psychological altruism.

This raises sociobiology’s perennial problem: how do we distinguish between behaviors directly encoded in our genes, and those that are mere byproducts of our big brains and complex culture? Humans evolved in small social groups, and it is likely that many traits, such as longing to be with others, are genetic products of that history. But other behaviors may simply be nongenetic effects of sociality. Are we docile and altruistic by instinct, or do we learn as children that obeying our parents and sharing our toys pay dividends? Although all human behaviors are “evolutionary” in the trivial sense that they originate in our evolved brains, there is no scientific basis for Wilson’s claim that religion-promoting behaviors are hard-wired in those brains.

Finally, even hard-wired social behaviors may have been beneficial to individuals, obviating the need to invoke group selection. As Lee Dugatkin emphasizes in Cooperation among Animals: An Evolutionary Perspective (Oxford University Press, 1997), cooperation can evolve because it is advantageous for each individual involved. A group-hunting lion will always be better off than a solitary hunter. Likewise, moral systems and psychological altruism may benefit the individual by increasing group solidarity. After all, psychological altruism is not biological altruism: I sacrifice no reproductive potential by driving a blind person to church.

Curiously, Wilson’s work was funded by the John Templeton Foundation, which is dedicated to promoting harmony between science and religion. But Darwin’s Cathedral creates no such rapprochement, for it sees religion as an offshoot of evolutionary biology. It thus represents one more foray in sociobiology’s continuing quest to ingest all areas of human thought, including sociology, psychology, aesthetics, and ethics. Wilson’s “reconciliation” between science and religion recalls the old story of the Biblical Zoo, containing a cage in which a lion and a lamb snuggle peacefully together. Amazed at the sight, a visitor calls over the attendant. “A lion and a lamb together—this is the very fulfillment of Isaiah’s prophecy! How did you do it?” It’s easy,” replies the attendant. “We just put in a new lamb every morning.”

_______________________
Jerry Coyne is a professor in the Department of Ecology and Evolution at the University of Chicago