Nothing we’ve said so far indicates anything about female preference. What if she finds the alpha male arrogant, boorish, taking too much for granted? Or just plain ugly? Does she have the right to refuse? At least among hamsters, this is not an option.
Here’s an experiment17 done on Syrian hamsters by the psychologist Patricia Brown and her colleagues: To begin, males, matched for size and body weight, were allowed to interact with one another in pairs to establish dominance. Chasing and biting were among the behaviors counted as dominant; defensive postures, evasions, raised tails, and full cowering submission were counted as subordinate traits. The dominants accounted for over ten times more aggressive acts than an equal number of subordinate animals; the subordinate animals tallied ten times more submissive acts than those judged dominant. It never took more than an hour for a pair of hamsters to decide who was dominant and who was subordinate.
Now although these males knew how to fight, they’d never had a sexual experience. Each of them was made to wear a little leather harness attached to a tether, which, like a dog’s leash, limited how far he could roam. Next, an ovulating female was released; she could have access to the tethered males, but beyond a certain point their leashes would prevent them from following her or offering unwelcome attentions. Whatever sexual contact might be in the offing would be on her terms.
We imagine her, steely-eyed, slowly looking the males over head to tail in their kinky leather outfits. Because the earlier dominance conflict was largely ritual, there were no injuries to betray which was the subordinate animal. Each male was in its own partitioned area, so they could not see one another and betray to the female their relative status through gestures of dominance or submission. Would she, despite the absence of signs apparent to the human observers, select the dominant male? Or would she find some other trait more attractive? The females were not hesitant or demure. In less than five minutes, every one of them presented herself for copulation to one of the males. In every case it was the dominant male. Prior familiarity was not required. Somehow she knew. There were no questions asked about his education, family, financial prospects, or the gentleness of his disposition. Every female was eager for sex with the dominant male.
How could the female know? The answer seems to be that she could smell dominance. There is literally a chemistry between them, the odor of power. The dominant males give off some effluvium, some pheromone that subordinate males do not.18
“I’m a celebrity. That’s what celebrities do,” offered one-time heavyweight boxing champion Mike Tyson in explaining his scattershot propositioning of virtually every contestant at a beauty pageant. Former U.S. Secretary of State Henry Kissinger, not known for his looks, explained a beautiful actress’s attraction to him in these words: “Power is the greatest aphrodisiac.”
Dominant males preferentially copulate with attractive females. The females are as accommodating as they can be. They crouch down, they raise their hindquarters, they lift their tails out of the way. (We’re back to hamsters.) In Brown’s rodents-in-motorcycle-jackets experiment, during the first half hour of mating the number of “intromissions” by dominant males averaged 40; those subordinate males able to score at all (usually after the dominants were done) averaged a measly 1.6 for the half hour.
Now suppose you grow up in a society in which such behavior is the community standard. Wouldn’t you tend to conclude that the animal who mounts and who makes repeated pelvic thrusts is the dominant partner, while the animal who crouches, who is receptive and passive, is subordinate in rank? Would it be surprising if this powerful symbol of dominance and submission were generalized in the gestural and postural vocabulary of the status-obsessed males?
Before the invention of language, animals need clear symbols to communicate with one another. There’s a well-developed non-verbal language, which we’ve already described, including “My belly’s up and I surrender” and “I could bite you but I won’t, so let’s be friends.” It would be very natural if everyday reminders of status in the rank hierarchy were established by brief ceremonial mountings of males by males. He who mounts is dominant; he who is mounted is subordinate. No “intromission” is required. Such symbolic language is in fact widespread, and we will discuss it in greater detail in later chapters. It may have little or no overt sexual content.
Under natural conditions, ordinary Norway rats—the same common variety whose social structure collapsed in Calhoun’s overcrowding experiments—arrange themselves into social hierarchies. A dominant might approach a submissive animal, sniff and lick its anogenital area, and mount it from the rear, holding on with the forepaws. The submissive animal might elevate its hindquarters so as to indicate its eagerness to be mounted. Male aggression in maintaining the dominance hierarchy includes banging flanks, rolling over and kicking, pinning the opponent with the forepaws, and boxing—the two animals actually stand toe-to-toe and let loose with left jabs and right uppercuts. Under normal conditions it’s rare that anyone is injured.
Even among lobsters the aggressive posture is to stand upright—indeed, on their toes (or at least the tips of their claws). The submissive posture is flat on the ground, legs somewhat akimbo. The idea is to show that you can’t (quickly) do any harm, even if you want to. Many gestures in a similar spirit can be found among humans. Police confronting possibly armed suspects will order them to raise their hands (so it’s clear they’re weaponless); or clasp their hands behind their necks (ditto); or lean at a high inclination angle against a wall (so their hands must support them); or lie prone. Submissive words are well and good (“I didn’t mean nothin’, honest”), but a police officer putting his or her life on the line requires a firmer postural guarantee.
In almost all higher mammals copulation occurs with the male entering the female’s vagina from behind. The female crouches down to assist the male in mounting her. She may make special motions to aid his entry, and those motions, like the bump and grind, become part of the symbolic language of enticement. The reason for the crouch is partly to present a favorable geometry for entry, but it also indicates that she has no intention of going anywhere. She’s not about to run away. Something similar can be seen in many other species. A male beetle come a-courting taps on the female’s carapace—in different beetle species, drumming with his feet, his antennae, his mouthparts, or his genitals—and she is instantly immobilized.19 The strange attractiveness to men of grotesquely deformed small feet (in China for nearly a millennium), and of very high heels (throughout the modern West), as well as traditional, constraining women’s clothing20 and the fetish of female helplessness in general, may be a human manifestation of the same symbolism.
In many species the alpha male systematically threatens any other male attempting to mate with any female in the group, especially when conception is possible. Because of clandestine impregnations by subordinate males—kleptogamy—in which the females are often willing partners, the alpha does not always succeed; but he’s highly motivated to try. This is true within female dominance hierarchies as well. In domestic fowl, for example, the alpha female tends to attack any female that so much as walks up to an adult male during the breeding season. In gelada baboons, in which there is a female dominance hierarchy, high-ranking females do not, on average, mate more frequently during ovulation than do the lower-ranking females; but the lower-ranking females rarely give birth. Something about their inferior status diminishes their fertility. Perhaps they are advertising ovulation when in fact no egg is released, or maybe they have many spontaneous abortions. But whatever it is, their low status prevents them from having babies. In marmosets, subordinate females tend to suppress their ovulations, but when they are freed from the female dominance hierarchy, they quickly become pregnant.21 Thus, genes contributing to high status in the female hierarchy—large stature, say, or superior social skills—get preferentially passed on to the next generation. This tends to stabilize a hereditary aristocracy.