Even in chimps the rise of a male to the alpha position and his tenure there is determined by his ability to command the loyalty of allies.'° So the alliance theory once more seems too general to explain the sudden increase in human intelligence. Moreover, like most of these theories, it explains language, tactical thinking, social exchange, and the like, but it does not explain some of the things to which human beings devote much of their mental energy: music and humor, for example: WITTINESS AND SEXINESS
At least the Machiavelli theory proposes an adversary for the human brain that is its equal, however clever it gets: Few of my readers will need reminding of the ruthlessness that human beings
can show when in pursuit of self-interest: There is no such thing as being clever enough just as there is no such thing as being good enough at chess. Either you win or you do not: If winning pits you against a better opponent, as it does in the evolutionary tournament generation after generation, then the pressure to get better and better never lets up. The way the brains of human beings have gotten bigger at an accelerating pace implies that some such within-species arms race is at work:
So argues Geoffrey Miller: After laying bare the inadequa-cies of the conventional theories about intelligence, he takes a surprising turn.
I suggest that the neocortex is not primarily or exclu-sively a device for toolmaking, bipedal walking, fire-using, warfare, hunting, gathering, or avoiding savanna predators: None of these postulated functions alone can explain its explosive development in our lineage and not in other closely related species.:.. The neocortex is largely a courtship device to attract and retain sexual mates: Its specific evolutionary function is to stimulate and entertain other people, and to assess the stimula-tion attempts of others:'
The only way, he suggests, that sufficient evolutionary pressure could suddenly and capriciously be sustained in one species to enlarge an organ far beyond its normal size is sexual selection. 'Just as the peahen is satisfied with nothing less than a visually brilliant display of peacock plumage, I postulate that hominid males and females became satisfied with nothing less than psychologically brilliant, fascinating, articulate, entertaining companions.' Miller 's use of the peacock is deliberate: Wherever else in the animal kingdom we find greatly exaggerated and enlarged ornaments, we have been able to explain them by the runaway, sexy-son, Fisher effect of intense sexual selection (or the equally powerful Good-genes effect, as described in chapter 5): Sexual selection, as we have seen, is very different from natural selection in its effects, THE INTELLECTUAL CHESS GAME
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for it does no? solve survival problems, it makes them worse: Female choice causes peacocks ' tails to grow longer until they become a burden—then demands that they grow longer still: Miller used the wrong word: Peahens are never satisfied: And so, having found a force that produces exponential change in ornaments, it seems perverse not to consider it when trying to explain the exponential expansion of the brain:
Miller adduces some circumstantial evidence for his view: Surveys consistently place intelligence, sense of humor, creativity, and interesting personality above even such things as wealth and beauty in lists of desirable characteristics in both sexes.' Yet these characteristics fail entirely to predict youth, status, fertility, or parental ability, so evolutionists tend to ignore them—but there they are, right at the top of the list: Just as a peacock 's tail is no guide to his ability as a father but despotic fashion punishes those who cease to respect it, so Miller suggests that men and women dare not step off the treadmill of selecting the wittiest, most creative and articulate person available with whom to mate. (Note that conventional 'intelligence ' as measured by examinations is not what he is talking about.)
Likewise, the manner in which sexual selection capriciously seizes upon preexisting perceptual biases fits with the fact that apes are by nature naturally 'curious, playful, easily bored, and appreciative of simulation. ' Miller suggests that to keep a husband around long enough to help in raising children, women would have needed to be as varied and creative in their behavior as possible, which he calls the Scheherazade effect after the Arabian storyteller who entranced the Sultan with I,001 tales so that he did not abandon her (and execute her) for another courtesan. The same would have applied to males who wanted to attract females, which Miller calls the Dionysus effect after the Greek god of dance, music, intoxication, and seduction: He might also have called it the Mick Jagger effect; he admitted to me one day that he could not understand what made strutting, middle-aged rock stars so attractive to women. In this respect Don Symons noted that tribal chiefs are both gifted orators and highly polygamous men. 53
Miller notes that the bigger the brain became, the more necessary long-term pair bonds were. A human infant is born helpless and premature. If it were as advanced at birth as an ape, it would be twenty-one months in the womb.' But the human pelvis is simply incapable of bearing a child with a head that big, so it is born at nine months and treated like a helpless, external fetus for the next year, not even beginning to walk until it is at the age when it would expect to enter the world. This helplessness further enhances the pressure on women to keep men around to help feed them when encumbered with a child—the Scheherazade effect.
Miller finds that the most commonly voiced objection to the Scheherazade effect is that most people are not witty and creative but are dull and predictable. True enough, but compared to what? Our standards for what is considered entertaining have, if Miller is right, evolved as fast as our wit: 'I think male readers may find it hard to imagine some four-foot-tall, half-hairy, flat-chested, hominid females being sexier than similar hominids, ' wrote Miller in a letter to me (referring to 'Lucy '). 'We 're spoiled because sexual selection has already driven us so far that it 's hard to appreciate how any point we 've passed could have been considered an improvement: We are positively turned
Miller 's theory draws attention to several facts that have remained unexplained in other theories, namely that dance, music, humor, and sexual foreplay are all features unique to human beings: Following the Tooby-Cosmides logic, we cannot argue that these are mere cultural habits foisted on us by ' society. ' Plainly a desire to hear rhythmic tunes or to be made to laugh by wit develops innately: Following Miller we note that they are characterized by obsessions with novelty and virtuosity and much practiced by the young: From Beatlemania to Madonna (and back again to Orpheus), the sexual fascination of youth with musical creativity has been obvious. It is a human universal.
It is crucial for Miller 's theory that human beings are especially selective about their mates: Indeed, among apes, people are unique in that both sexes are extremely choosy: A gorilla female is THE INTELLECTUAL CHESS GAME
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happy to be mated with whoever 'owns' her harem: A gorilla male will mate with any estral female he can find: A chimp female is keen to mate with many different males in the troop. A chimp male will mate with any female in season: But women are highly selective about the men with whom they, mate: So indeed are men: True, they are easily persuaded to go to bed with beautiful young women—
