The Moral Animal: Why We Are, the Way We Are: The New Science of Evolutionary Psychology (28 page)

This perception of a fundamental unity among human beings — a human nature — is the first step toward becoming an evolutionary psychologist. The second step — trying to explain parts of that nature in terms of natural selection — Darwin also took. In particular, he tried to explain parts of the human psyche that, to judge by some of his letters from the Beagle, you might have thought the Fuegians and other "savages" didn't possess at all: "the moral sense, which tells us what we ought to do, and ... the conscience which reproves us if we disobey it ..."
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Once again, as with the sterility of insects, Darwin had chosen to confront a major obstacle to his theory of evolution. The moral sentiments are hardly an obvious product of natural selection.

To a certain extent, Darwin's solution to the sterility problem was a solution to the morality problem. His concept of "family" selection, or kin selection, can explain altruism in mammals, and hence conscience. But kin selection accounts only for acts of conscience within the family. And human beings are amply able to feel sympathy for nonkin, to help them, and to feel guilty about failing to. Bronislaw Malinowski, in the early twentieth century, would note that the Trobriand Islanders have two words for "friend," depending on whether the friend is within one's own clan or from another clan. He translated the words as meaning "friend within the barrier" and
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"friend across the barrier."
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Even the Fuegians, those "miserable savages," had been able to make friends with a young white-skinned man who came from across the ocean. The question remains, even after the theory of kin selection: Why do we have friends across the barrier?

The question is even larger than that. Human beings can feel sympathy for people "across the barrier" who aren't friends — people, indeed, whom they don't even know. Why is this? Why are there Good Samaritans? Why do most people have trouble walking past a beggar without at least a twinge of discomfort?

Darwin found an answer to these questions. His answer, it now seems, is misguided. But it is misguided in a very illuminating way. It rests on a particular kind of confusion that periodically afflicted biology until late this century, when it was finally swept away and the path was cleared for modern evolutionary psychology. What's more, Darwin's analysis of human morality, up to the point where he made his big mistake, is in some ways exemplary; in places it is a paragon of the method of evolutionary psychology even by today's standards.

The first problem facing anyone who seeks evolutionary insight into morality is its huge diversity. There is the prudishness and gentility of Victorian England, the morally sanctioned savagery of savages, and lots in between. Darwin wrote with some perplexity of the "absurd rules of conduct" reflected in, for example, the "horror felt by a Hindoo who breaks his caste" and the "shame of a Mahometan woman who exposes her face."
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If morality is grounded in human biology, how can moral codes differ so widely? Do Arabs and Africans and Englishmen have different "morality genes"?

This is not the explanation that modern evolutionary psychology favors, and not the one Darwin stressed. To be sure, he did believe the races had inborn mental differences, some of them morally relevant.
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This belief was standard in the nineteenth century, an era when some scholars (Darwin not among them) argued strenuously that the races weren't races at all, but species. Still, Darwin believed
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the world's varied moral customs were rooted — in at least a general sense — in a common human nature.

To begin with, he noted the deep sensitivity of all human beings to public opinion. "The love of approbation and the dread of infamy, as well as the bestowal of praise or blame" are grounded in instinct, he asserted. A breach of norms can cause a man "agony," and the violation of some trivial bit of etiquette, when recalled even years after, can bring back a "burning sense of shame."
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Thus, adherence to any moral rule has an innate basis. It is only the specific contents of moral codes that are not inborn.

Why do the contents vary so? Darwin believed different peoples have different rules because, for their own historical reasons, they judge different norms to be in the interest of the community.

Often, Darwin said, these judgments are in error, yielding patterns of behavior that are pointless, if not, indeed, "in complete opposition to the true welfare and happiness of mankind." One gets the impression that, from Darwin's point of view, it was England, or at least Europe, in which the fewest errors had been made. And savages, plainly, had made more than their share. They seemed to possess "insufficient powers of reasoning" to discern nonobvious connections between moral laws and public welfare, and they lacked, perhaps constitutionally, self-discipline; "their utter licentiousness, not to mention unnatural crimes, is something astounding."
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Still, Darwin believed that none of this savagery should distract us from the second universal element in human morality. Fuegians and Englishmen alike possessed the "social instincts," central among them sympathy for their fellow man. "[F]eelings of sympathy and kindness are common, especially during sickness, between the members of the same tribe... ."And "many instances have been recorded of barbarians, ... not guided by any religious motive, who have deliberately as prisoners sacrified their lives, rather than betray their comrades; and surely their conduct ought to be considered moral."
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True, barbarians had an unfortunate tendency to define everyone outside of their tribe as morally worthless, even to the point of deeming harm to outsiders an honorable endeavor. Indeed, "it has been recorded that an Indian Thug conscientiously regretted that he had not strangled and robbed as many travellers as did his father before
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him."
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Still, this was a question of the scope of sympathy, not of its existence; so long as all peoples have a core capacity for moral concern, no people is beyond edification. In The Voyage of the Beagle, Darwin wrote about an island off the coast of Chile: "It is a pleasant thing to see the aborigines advanced to the same degree of civilization, however low that may be, which their white conquerors have attained."
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Any savages who feel flattered that Darwin accorded them full possession of sympathetic impulses and the underlying social instincts should be aware that he bestowed a similar honor on some nonhuman forms of life. He saw sympathy in reports of crows that dutifully fed their blind compatriots and of baboons that heroically saved their youngsters from a pack of dogs; and "Who can say what cows feel, when they surround and stare intently on a dying or dead companion?"
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Darwin described signs of tenderness among two chimpanzees, relayed to him by a zookeeper who watched their first encounter: "They sat opposite, touching each other with their much protruded lips; and the one put his hand on the shoulder of the other. They then mutually folded each other in their arms. Afterwards they stood up, each with one arm on the shoulder of the other, lifted their heads, opened their mouths, and yelled with delight."
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Some of these examples may be cases of altruism among close relatives, in which case the simple explanation is kin selection. And, for that matter, the scene with the chimps getting acquainted may have been embellished by an anthropomorphizing zookeeper. But, for the record, chimpanzees do, in fact, form friendships, and this single fact is sufficient for the point Darwin was making: that however special we may consider our species, we are not unique in our capacity for sympathetic behavior, even beyond the confines of family.

Certainly, Darwin noted, human beings carry moral behavior to unique lengths. They can, via complex language, learn precisely what sort of conduct is expected of them in the name of the common good. And they can look back into the past, recall the ultimately painful result of allowing their "social instincts" to be overridden by baser instincts, and resolve to do better. Indeed, Darwin suggested, on grounds such as these, that the word moral itself be reserved for our species.
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Still, at the root of this full-blown morality he saw a social
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instinct that long predates humanity, even if human evolution had enriched it.

In figuring out how evolution favored moral (or any other) impulses, it is critical to focus on the behaviors they bring. After all, behavior, not thought or emotion, is what natural selection passes judgment on; acts, not the feelings themselves, directly guide the transportation of genes. Darwin perfectly understood this principle. "It has often been assumed that animals were in the first place rendered social, arid that they feel as a consequence uncomfortable when separated from each other, and comfortable whilst together; but it is a more probable view that these sensations were first developed, in order that those animals which would profit by living in society, should be induced to live together, ... for with those animals which were benefited by living in close association, the individuals which took the greatest pleasure in society would best escape various dangers; whilst those that cared least for their comrades and lived solitary would perish in greater numbers."
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In the course of his basically sound approach to evolutionary psychology, Darwin succumbed to a temptation known as group selectionism. Consider his central explanation for the evolution of the moral sense. In
The Descent of Man
he wrote that "an advancement in the standard of morality and an increase in the number of well-endowed men will certainly give an immense advantage to one tribe over another. There can be no doubt that a tribe including many members who, from possessing in a high degree the spirit of patriotism, fidelity, obedience, courage, and sympathy, were always ready to give aid to each other and to sacrifice themselves for the common good, would be victorious over most other tribes; and this would be natural selection."
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Yes, this would be natural selection, if it actually happened. But, while it isn't impossible for it to happen, the more you think about it, the less likely it seems. Darwin himself had seen the main snag only a few pages earlier: "It is extremely doubtful whether the offspring of the more sympathetic and benevolent parents, or of those which were the most faithful to their comrades, would be reared in
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greater number than the children of selfish and treacherous parents of the same tribe." On the contrary, the bravest, most self-sacrificial men "would on an average perish in larger number than other men." A noble man "would often leave no offspring to inherit his noble nature."
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Exactly. So even though a tribe full of selfless people would prevail over a tribe full of selfish people, it is hard to see how a tribe would get full of selfless people in the first place. Everyday prehistoric life, with its normal share of adversity, would presumably favor the genes of people who, say, hoarded food rather than share it, or let neighbors fight their own battles rather than risk injury; and this intratribal advantage would, if anything, have grown when the intertribal competition at the heart of Darwin's group-selectionist theory heated up, as during war or famine (unless, after wars, societies took exceedingly good care of the kin of dead war heroes). So there might never be a way for biologically based impulses of selflessness to pervade a group. Even if you magically intervened and implanted "sympathetic" genes in 90 percent of the population, these would steadily lose out to their less ennobling rival genes.

Granted, as Darwin said, the resulting rampant selfishness might mean that this tribe perished in competition with another tribe. But all tribes are subject to the same internal logic, so the victors presumably wouldn't be paragons of virtue themselves. And any meager quantity of selflessness they had put to good use should, in theory, be declining even as they savored the fruits of victory.

The problem with Darwin's theory is a common problem with group-selectionist theories: it is hard to imagine group selection spreading some trait that individual selection on its own wouldn't favor; it is hard to imagine natural selection resolving a direct conflict between group welfare and individual welfare in favor of the group. To be sure, one can dream up scenarios — with particular rates of migration among groups, and particular rates of group extinction — where group selection might favor individual sacrifice; and there are a few biologists who believe group selection did play an important role in human evolution.
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Still, group-selectionist scenarios do tend to be a bit convoluted. Indeed, George Williams found them so generally onerous that he proposed, in
Adaptation and Natural Selection
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an official bias against them: "One should postulate adaptation at no higher a level than is necessitated by the facts."
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In other words: first look very hard for a way that genes underlying a trait could be favored in everyday, head-to-head competition. Only after failing should you resort to competition between separate populations, and then with great caution. This has become the unofficial credo of the new paradigm.

In the same book, Williams put his doctrine to vivid use. Without resort to group selection, he proposed what is now the accepted explanation for the human moral sentiments. Writing in the mid-sixties, just after Hamilton had explained the origin of altruism among kin, Williams suggested a way that evolution could extend altruism beyond the barrier of kinship.
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