Is There a Gene for Compassion?

By Steven Pinker

New York Times Book Review
September 25, 1994

The New Science of Evolutionary Psychology.
By Robert Wright.
Illustrated. 467 pp.
New York: Pantheon Books. $27.50.

THE mind is a product of the brain, and the brain is a product of evolution's organizing force, natural selection. This simple Darwinian truth has illuminated vast stretches of our mental life. Why do we see in depth and enjoy sweets? Not because minds have to be that way. Most mammals lack stereo vision, and dung flies surely find dung delicious. No, our experiences are adaptations of a brain that allowed our ancestors to survive in an environment where a fall from a tree could mean death, and ripe fruit contained precious glucose.

But what about our higher thoughts and feelings: our devotion to children, love for spouses, loyalty to friends, obedience to principle, respect for the worthy, outrage at the wicked? These too are products of a brain that could have been wired otherwise. Did we inherit these noble sentiments because they served the reproductive interests of our ancestors? How could that have happened, if evolution is a game in which nice guys finish last? And if our moral psychology is a Darwinian adaptation, what does that say about human nature? About social policy, which always presupposes something about human nature? About morality itself?

These are the questions asked and answered in Robert Wright's fiercely intelligent, beautifully written and engrossingly original book "The Moral Animal." It lucidly explains our understanding of the evolution of human moral sentiments and draws out provocative implications for sexual, family, office and societal politics. But Mr. Wright's main lesson comes from the very fact that morality is an adaptation designed to maximize genetic self-interest, a function that is entirely hidden from our conscious experience. Our intuitive moral principles, he says, have no claim to inherent truth and should be distrusted. In Darwin's wake we must reconstruct morality from the ground up.

Mr. Wright, a columnist and editor at The New Republic and the author of "Three Scientists and Their Gods," writes with a consistent, irreverent wit that does not hide a heartfelt seriousness of purpose. He has also used a clever conceit: alternating explanations of Darwinism with installments of a revisionist biography of the saintly Darwin, in which his life choices are explained in the cynical light of Darwinian psychology. The gentle suitor, dedicated husband, doting father, generous colleague, idealistic scientist and painful self-doubter is deconstructed as a cunning fitness-maximizer. As Mr. Wright sums it up: "What an animal!" But he doesn't single out Darwin for censure; he sees him as the best of a bad lot: us.

Mr. Wright takes care to explain the theory and the data leading up to his conclusions. Forget the sanctimonious nature documentaries in which wolves target the old and sick rabbits for the harmony of the ecosystem, and the weak seals stay celibate for the benefit of the species. Such public-mindedness, however laudable, is not what natural selection selects: a selfish mutant would quickly out-reproduce its altruistic competitors. Any selfless behavior in the natural world requires an explanation.

Take parenting. Who could be cynical about a mother's love? Mr. Wright explains how it arises from selfish genes: any gene that shapes an animal to help its relatives will, with some probability, be favoring copies of that gene sitting inside those relatives. Thus, parental love is not unmeasured. Though every offspring values itself the most and craves all of a parent's attention, parents are predicted to nurture each offspring in proportion to the offspring's actuarially estimated reproductive potential.

Darwin lost three of his 10 children. He passed through stages of grief and acceptance for the loss of his 3-week-old daughter and for his retarded 18-month-old son, but that the devastation following the loss of his talented 10-year-old daughter lasted all his life.

"The Moral Animal" is no more sentimental about courtship and romance. The sex that invests more in offspring (the female, in most animals) becomes a limited resource for which the other sex competes. In humans, both sexes invest in children -- women by the standard mammalian commitment of pregnancy and nursing (a sharp limitation on their lifetime reproductive output), men by the more iffy provision of food and care. Thus, men and women compete for each other's favors, but keep score by somewhat different rules. Men place a greater value on signs of fertility (such as youth) and sexual fidelity (such as coyness); women place a greater value on signs of a lifelong provider (status, strength, devotion). The result is a roiling marriage market, complete with advertising campaigns and close-to-the-vest assessments of bargaining positions. Mr. Wright illustrates the marriage market using the diaries and correspondence of Charles Darwin and his fiancee, Emma Wedgwood.

Once a courtship is consummated, men and women have a common interest in their offspring. But love is not always infinite and everlasting. Infidelity is a siren, always giving males an opportunity to multiply their progeny and sometimes giving females an opportunity to receive additional male investment. The costs to the cuckold are also asymmetrical. The wife of an adulterer is certain that a baby emerging from her body carries her own genes, but the husband of an adulteress is in danger of lavishing resources on some other man's genes. Thus is joined the battle of the sexes.

Friendship and other forms of decency toward nonrelatives are rooted in reciprocity: a creature will extend help in return for the expectation of help in the future. But such favor-trading is always vulnerable to cheaters. For reciprocity to have evolved, it must have been accompanied by the cognitive apparatus necessary to remember who has given and taken. It must also have been supported by emotions like gratitude, anger, self-righteousness and guilt, emotions that impel one to favor reciprocators, punish nonreciprocators and stay on the positive side of others' ledgers.

In humans, the talkative species, long-term reciprocity creates an arms race of impression management. Everyone tries to show signs of integrity (exceeding that in actual behavior), while developing hypersensitive radar for such hypocrisy in others. Since an adversary's social radar will pick up any twitch or inconsistency that leaks the awful truth, it can even pay to deceive oneself about one's own intentions, so that there is nothing to leak. As Mr. Wright puts it: "The human brain is, in large part, a machine for winning arguments, a machine for convincing others that its owner is in the right -- and thus a machine for convincing its owner of the same thing. The brain is like a good lawyer: given any set of interests to defend, it sets about convincing the world of their moral and logical worth, regardless of whether they in fact have any of either."

MR. WRIGHT is aware of the furor that greeted these ideas when they were presented as part of the new science of sociobiology in the 1970's. The newsmagazines misread the theory as claiming that we are puppets controlled by our genes. (In fact, most sociobiologists assumed that behavior implicates both genes and culture; they were simply explaining why the genetic component is the way it is.) Social scientists, schooled in the idea that humans inherit only a general learning mechanism that absorbs a culture's mores (bad ones now, better ones in a reformed society), resisted the idea of an inherited complex human nature. And the forces of what would now be called political correctness accused sociobiologists of racism, sexism and oppression of the working class. Mr. Wright gives us a chilling reminder of the intolerant atmosphere by reproducing a 1984 poster urging students to bring noisemakers to a public lecture by the sociobiologist E. O. Wilson.

Mr. Wright, who sees no contradiction between sociobiology and his egalitarian politics, notes how the climate has changed. Many aspects of human nature can no longer be glibly written off as products of Western enculturation now that cross-cultural surveys have shown them to be ubiquitous. The idea of innate sex differences is no longer anathema to many feminists. And cooler heads can see that even if a human nature common to all members of the species is innate, this does not mean that the differences among individuals, races or classes are also innate. Evolutionists now tread gingerly across the politicized mine field of human behavior, taking pains not to sanction evolution's way as inevitable or desirable.

Most important, the science itself has changed. Natural selection used to be described as an omnipresent force shaping behavior to maximize fitness. But there are two good reasons why it can't be. First, natural selection does not hover over us pulling the strings of behavior directly. It acts by designing the generator of behavior -- the mind, which is loaded with information-processing mechanisms designed to pursue certain goals (which we experience as emotions). Actual behavior is the tortuous outcome of many conflicting motives, played out on the chessboard of opportunities and constraints defined by circumstances and by other people's behavior. Evolutionary theory does not, for example, predict that men will actually behave as rapacious womanizers; it can predict only that some part of the male mind will want to. Jimmy Carter, after all, committed adultery only in his heart.

SECOND, selection operates over thousands of generations. Ninety-nine percent of human existence was spent in small hunter-gatherer bands. Our brain and its desires are adapted to that long-vanished environment, not to brand-new agricultural and industrial civilizations. That means that modern nonadaptive behavior, like celibacy, adoption and birth control, needs no farfetched explanation. Our ancestors' environment lacked the social and technological inducements for these practices, so there was no selection pressure to resist them. If birth control pills (a means of Darwinian suicide) had grown on trees in the Pleistocene savanna, we might have evolved to find them as terrifying as venomous snakes.

Mr. Wright believes that evolutionary psychology (as this mixture of cognition and updated sociobiology is called) has profound implications for the human condition, particularly for sexual politics. He suggests that Victorian sexual morals, including the sexual double standard for men and women, and the "madonna-whore" dichotomy (in which coy women are valued as potential wives and loose women are denigrated as short-term conquests), offer tactical advantages to women.

"The Moral Animal" turns other popular beliefs inside out. Monogamy, Mr. Wright says, does not favor the interests of most women, particularly lower-status women. Most human cultures throughout history have been mildly polygynous, with wealthier men attracting several wives. Though women in these cultures "are often less than eager to share a man," he writes, "typically, they would rather do that than live in poverty with the undivided attention of a ne'er-do-well." Monogamy instead favors lower-status men, who in a polygynous society would be frozen out of the marriage market by a wife-collecting elite. It is no coincidence that Christianity has advocated monogamy and pitched its message to poor and powerless men.

One of the worst options for women and children, according to Mr. Wright, is what we now have, a near-equivalent of polygyny: serial divorce and remarriage. With real polygyny, wealthy men must support their old families after acquiring new ones; with serial divorce, the old families are abandoned. Mr. Wright challenges us to think through the implications:

"Johnny Carson, like many wealthy, high-status males, spent his career monopolizing long stretches of the reproductive years of a series of young women. Somewhere out there is a man who wanted a family and a beautiful wife and, if it hadn't been for Johnny Carson, would have married one of these women. And if this man has managed to find another woman, she was similarly snatched from the jaws of some other man. And so on -- a domino effect: a scarcity of fertile females trickles down the social scale."

His argument is not just a thought exercise; he pursues the consequences of the arithmetic: "Whereas in 1960 the fraction of the population age 40 or older that had never married was about the same for men and women, by 1990 the fraction was markedly larger for men than for women.

"It is not crazy to think that there are homeless alcoholics and rapists who, had they come of age in a pre-1960's social climate, amid more equally distributed female resources, would have early on found a wife and adopted a lower-risk, less destructive life style. . . . If polygyny would indeed have pernicious effects on society's less fortunate men, and indirectly on the rest of us, then it isn't enough to just oppose legalized polygyny. (Legalized polygyny wasn't a looming political threat last time I checked, anyway.) We have to worry about the de facto polygyny that already exists."

Mr. Wright also wants to shake up received wisdom about our sense of right and wrong in general. Our ethical intuitions, he says, ultimately serve our genetic self-interest and have no claim to inherent rectitude; they are "vestiges of organic history on a particular planet." He cites intolerant self-righteousness and the sadistic thirst for retribution as examples of how destructive moral impulses can be. But he is no nihilist; he is tormented by the discrepancy between the self-evident need for moral principles and their intellectual groundlessness. He tries to build a minimalist ethical philosophy from scratch, which takes the form of classical utilitarianism: what is right is the greatest happiness for the greatest number.

I FOUND his larger ethical arguments problematic. Mr. Wright's case for our ineluctable hypocrisy gets an undeserved boost from the metaphor of the selfish gene. When a person's public stance is selfless but his private motives serve his interests, we can call it hypocrisy. However, when a person's public stance and private motives are both selfless but those motives came about because they once served the interests of his ancestors' genes, we have not uncovered hypocrisy; we have invoked a scientific explanation couched at a different level of analysis. Color depends on properties of colorless molecules; solid objects are made of atoms that are mostly empty space. That does not mean that peacocks are colorless or that Gibraltar is a mirage. Similarly, selfless people designed by selfish genes are not selfish. The evolutionary causes of our motives can't be judged as if they are our motives.

There is another weakness in Mr. Wright's argument about the ultimate groundlessness of morality. He implies that because the moral sense evolved as just another biological organ, its contents are figments. But that does not follow. A faculty could have evolved to mesh with abstract principles that are in some sense "out there" waiting for suitable organisms to discover them. We evolved a mind that can grasp number, but that does not mean that 1 + 1 = 2 is a product of our imaginations. An evolutionary psychology that sees the moral sense as a biological adaptation is perfectly compatible with an ethical philosophy that sees moral principles as having a logic and justification of their own.

Indeed, there are well-known problems with the bare-bones utilitarianism that Mr. Wright feels is the most we can eke out of the Darwinian void, and he does not even address them: Should we indulge a sicko who gets more net happiness from killing than his victims do from living? Should we publicly execute a framed innocent man if it would deter a thousand murderers? Our intuitions shout "no," suggesting that inherent moral principles like individual rights are not so easy to dismiss.


Maintained by Francis F. Steen, Communication Studies, University of California Los Angeles