The Moral Animal: Why We Are, the Way We Are: The New Science of Evolutionary Psychology (5 page)

Since each adaptation, having fixed itself in the population, thus changes the social environment, adaptation only invites more adaptation. Once all parents have the XXL gene, it gives no parent an edge in the ongoing contest to create the most viable and prolific offspring. The arms race continues. In this case, it's an arms race of love. Often, it's not.

It is fashionable in some circles to downplay the whole idea of adaptation, of coherent evolutionary design. Popularizers of biological thought often emphasize not the role of fitness in evolutionary change but the role of randomness and happenstance. Some climate shift may come out of the blue and extinguish unlucky species of flora and fauna, changing the whole context of evolution for any species lucky enough to survive the calamity. A roll of the cosmic dice and suddenly all bets are off. Certainly that happens, and this is indeed one sense in which "randomness" greatly affects evolution. There are other senses as well. For example, new traits on which natural selection passes judgment seem to be randomly generated.
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But none of the "randomness" in natural selection should be allowed to obscure its central feature: that the overriding criterion of
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organic design is fitness. Yes, the dice do get rerolled, and the context of evolution changes. A feature that is adaptive today may not be adaptive tomorrow. So natural selection often finds itself amending outmoded features. This ongoing adjustment to circumstance can give organic life a certain jerry-built quality. (It's the reason people have back trouble; if you were designing a walking organism from scratch rather than incrementally adapting a former tree-dweller, you would never have built such bad backs.) Nonetheless, changes in circumstance are typically gradual enough for evolution to keep pace (even if it has to break into a trot now and then, when selective pressure becomes severe), and it often does so ingeniously.

And all along the way, its definition of good design remains the same. The thousands and thousands of genes that influence human behavior — genes that build the brain and govern neurotransmitters and other hormones, thus defining our "mental organs" — are here for a reason. And the reason is that they goaded our ancestors into getting their genes into the next generation. If the theory of natural selection is correct, then essentially everything about the human mind should be intelligible in these terms. The basic ways we feel about each other, the basic kinds of things we think about each other and say to each other, are with us today by virtue of their past contribution to genetic fitness.

No human behavior affects the transmission of genes more obviously than sex. So no parts of human psychology are clearer candidates for evolutionary explanation than the states of mind that lead to sex: raw lust, dreamy infatuation, sturdy (or at least sturdy-feeling) love, and so on — the basic forces amid which people all over the world, including Charles Darwin, have come of age.

When Darwin left England he was twenty-two and, presumably, flooded with the hormones that young men are, by design, flooded with. He had been sweet on a couple of local girls, especially the pretty, popular, and highly coquettish Fanny Owen. He once let her shoot a hunting gun, and she looked so charming, gamely pretending its kick hadn't hurt her shoulder, that he would recall the incident
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decades later with evident fondness.
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From Cambridge he conducted a tenuous flirtation with her by mail, but it isn't clear that he ever so much as kissed her.

While Darwin was at Cambridge, prostitutes were available, not to mention the occasional lower-class girl who might settle for less explicit payment. But university proctors prowled the streets near campus, ready to arrest women who could plausibly be accused of "streetwalking." Darwin had been warned by his brother never to be seen with girls. His closest known connection with illicit sex is when he sent money to a friend who had dropped out of school after siring a bastard.
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Darwin may well have left the shores of England a virgin.
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And the next five years, spent mainly on a ninety-foot ship with six dozen males, wouldn't provide many opportunities to change that status, at least not through conventional channels.

For that matter, sex wouldn't be abundantly available on his return either. This was, after all, Victorian England. Prostitutes could be had in London (where Darwin would take up residence), but sex with a "respectable" woman, a woman of Darwin's class, was more elusive — close to impossible in the absence of extreme measures, such as marriage.

The great gulf between these two forms of sex is one of the most famous elements of Victorian sexual morality — the "Madonna-whore" dichotomy. There were two kinds of women: the kind a bachelor would later marry and the kind he might now enjoy, the kind worthy of love and the kind that warranted only lust. A second moral attitude commonly traced to the Victorian age is the sexual double standard. Though this attribution is misleading, since Victorian moralists so strongly discouraged sexual license in men and women, it's true that a Victorian man's sexual extravagance raised fewer eyebrows than a woman's. It's also true that this distinction was closely linked to the Madonna-whore dichotomy. The great punishment awaiting a sexually adventurous Victorian woman was permanent consignment to the latter half of the dichotomy, which would greatly restrict her range of available husbands.

There is a tendency these days to reject and scoff at these aspects of Victorian morality. Rejecting them is fine, but to scoff at them is
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to overestimate our own moral advancement. The fact is that many men still speak openly about "sluts" and their proper use: great for recreation, but not for marriage. And even men (such as well-educated liberal ones) who wouldn't dream of talking like that may in fact act like that. Women sometimes complain about seemingly enlightened men who lavish respectful attention on them but then, after sex on the first or second date, never call again, as if early sex had turned the woman into a pariah. Similarly, while the double standard has waned in this century, it is still strong enough for women to complain about. Understanding the Victorian sexual climate can take us some distance toward understanding today's sexual climate.

The intellectual grounding of Victorian sexual morality was explicit: women and men are inherently different, most importantly in the libido department. Even Victorians who railed against male philandering stressed the difference. Dr. Acton wrote: "I should say that the majority of women (happily for them) are not very much troubled with sexual feeling of any kind. What men are habitually, women are only exceptionally. It is too true, I admit, as the divorce courts show, that there are some few women who have sexual desires so strong that they surpass those of men." This "nymphomania" is "a form of insanity." Still, "there can be no doubt that sexual feeling in the female is in the majority of cases in abeyance ... and even if roused (which in many instances it never can be) is very moderate compared with that of the male." One problem, said Dr. Acton, was that many young men are misled by the sight of "loose or, at least, low and vulgar women." They thus enter marriage with exaggerated notions of its sexual content. They don't understand that "the best mothers, wives, and managers of households, know little or nothing of sexual indulgences. Love of home, children, and domestic duties, are the only passions they feel."
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Some women who consider themselves excellent wives and mothers may hold a different opinion. And they may have strong supporting evidence. Still, the idea that there are some differences between the typical male and female sexual appetite, and that the male appetite is less finicky, draws much support from the new Darwinian paradigm. For that matter, it draws support from lots of other places. The recently popular premise that men and women are basically identical
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in nature seems to have fewer and fewer defenders. It is no longer, for example, a cardinal doctrine of feminism. A whole school of feminists — the "difference feminists," or "essentialists" — now accept that men and women are deeply different. What exactly "deeply" means is something they're often vague about, and many would rather not utter the word genes in this context. Until they do, they will likely remain in a state of disorientation, aware that the early feminist doctrine of innate sexual symmetry was incorrect (and that it may have in some ways harmed women) yet afraid to honestly explore the alternative.

If the new Darwinian view of sexuality did nothing more than endorse the coalescing conventional wisdom that men are a pretty libidinous group, it would be of meager value. But in fact it sheds light not just on animal impulses, like lust, but on the subtler contours of consciousness. "Sexual psychology," to an evolutionary psychologist, includes everything from an adolescent's fluctuating self-esteem to the aesthetic judgments men and women make about each other to the moral judgments they make about each other, and, for that matter, the moral judgments they make about members of their own sex. Two good examples are the Madonna-whore dichotomy and the sexual double standard. Both now appear to have roots in human nature — in mental mechanisms that people use to evaluate each other. This calls for a couple of disclaimers. First, to say something is a product of natural selection is not to say that it is unchangeable; just about any manifestation of human nature can be changed, given an apt alteration of the environment — though the required alteration will in some cases be prohibitively drastic. Second, to say that something is "natural" is not to say that it is good. There is no reason to adopt natural selection's "values" as our own. But presumably if we want to pursue values that are at odds with natural selection's, we need to know what we're up against. If we want to change some disconcertingly stubborn parts of our moral code, it would help to know where they come from. And where they
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come from is human nature, however complexly that nature is refracted by the many layers of circumstance and cultural inheritance through which it passes. No, there is no "double-standard gene." But yes, to understand the double standard we must understand our genes and how
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they affect our thoughts. We must understand the process that selected those genes and the strange criteria it used.

We'll spend the next few chapters exploring that process as it has shaped sexual psychology. Then, thus fortified, we'll return to Victorian morality, and to Darwin's own mind, and the mind of the woman he married. All of which will enable us to see our own situation — courtship and marriage at the end of the twentieth century — with new clarity.
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Darwin was wrong about sex.

He wasn't wrong about the males being the wooers. His reading of the basic characters of the two sexes holds up well today. "The female, ... with the rarest exception, is less eager than the male.... [S]he is coy, and may often be seen endeavouring for a long time to escape from the male. Every one who has attended to the habits of animals will be able to call to mind instances of this kind... . The exertion of some choice on the part of the female seems almost as general a law as the eagerness of the male."
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Nor was Darwin wrong about the consequences of this asymmetrical interest. He saw that female reticence left males competing with one another for scarce reproductive opportunities, and thus explained why males so often have built-in weapons — the horns of stags, the hornlike mandibles of stag beetles, the fierce canines of chimpanzees.
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Males not hereditarily equipped for combat with other
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males have been excluded from sex, and their traits have thus been discarded by natural selection.

Darwin also saw that the choosiness of females gives great moment to their choices. If they prefer to mate with particular kinds of males, those kinds will proliferate. Hence the ornamentation of so many male animals — a lizard's inflatable throat sack, brightly colored during the mating season; the immense, cumbersome tail of the peacock; and, again, the stag's horns, which seem more elaborate than the needs of combat alone would dictate.
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These decorations have evolved not because they aid in daily survival — if anything, they complicate it — but because they can so charm a female as to outweigh the everyday burdens they bring. (How it came to be in the genetic interest of females to be charmed by such things is another story, and a point of subtle disagreement among biologists.)
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Both of these variants of natural selection — combat among males and discernment by females — Darwin called "sexual selection." He took great pride in the idea, and justifiably so. Sexual selection is a nonobvious extension of his general theory that accounts for seeming exceptions to it (like garish colors that virtually say "Kill me" to predators), and that has not just endured over time but grown in scope.

What Darwin was wrong about was the evolutionary cause of female coyness and male eagerness. He saw that this imbalance of interest creates competition among males for precious reproductive slots, and he saw the consequences of this competition; but he didn't see what had created the imbalance. His attempt late in life to explain the phenomenon was unsuccessful.
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And, in fairness to him, whole generations of biologists would do no better.

Now that there is a consensus on the solution, the long failure to find it seems puzzling. It's a very simple solution. In this sense, sex is typical of many behaviors illuminated by natural selection; though the illumination has gotten truly powerful only within the last three decades, it could in principle have done so a century earlier, so plainly does it follow from Darwin's view of life. There is some subtle logic involved, so Darwin can be forgiven for not having seen the full scope of his theory. Still, if he were around today to hear evolutionary biologists talk about sex, he might well sink into one
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of his self-effacing funks, exclaiming at his obtuseness in not getting the picture sooner.