What Do Women Want

life of the compound. They didn’t belong to any particular family. They were merely breeders—and their peripheral status mimicked the male role in the wild. There, in Asian mountains or lowland forests, adult males lurked at the edges of female-run domains. The females invited them in to serve sexually. The males remained—desirable, dispensable—until the females lost interest in them. Then they were dismissed, replaced. In his compounds, Wallen removed the breeders and introduced new males about every three years, the time it took for them to become irrelevant, for their charms to wane, for the frequency of their copulations—almost always female-initiated—to fade. In the wild they seemed to stay attractive only slightly longer.
    “Rhesus females are very xenophobic when it comes to other females,” Wallen said. “Introduce a new female into the compound and she’ll be hounded until she dies. But when it comes to males, females have a bias toward novelty.”
    With his pale muzzle and russet back, Oppenheimer loped off once more and Deidrah trailed him. A child of hers, less than a year old, hurried behind her. Wallen’s assistants adored Deidrah. They loved her sprigs of out-of-control hair; they loved her personality, the quiet dignity she emanated most of the time, if not at the moment; and they loved the devotion of her mothering. Last year, upheaval in the compound had left her and her children vulnerable. Horribly frightened, they latched on to her and wouldn’t let go. “Literally, she could barely get up and walk without being dragged down by her kids,” Amy Henry, an assistant, said. “One held on to her tail. They wouldn’t let her go. She accepted it all with grace. She knew it was her responsibility to reassure them that it was okay. She’s always been a low-key monkey. But she gets very excited when she gives birth. And she gets very attached. I watched her carry her daughter on her back for a long time, right up to when she had a new baby. Not all moms will do that.”
    With hustling after Oppenheimer on her mind, though, maternal instinct was gone. She didn’t seem to see let alone know her baby; she kept leaving it alone, and it kept having to scoot after her. She positioned herself in front of Oppenheimer, crouched, and tapped a hand on the ground in a staccato rhythm. She tapped like this persistently, the rhesus equivalent of unbuckling a man’s belt. Yet her gesture contained a touch of hesitance. “She’s being careful, because all the females around her are higher ranked,” Wallen said. If they decided, for any reason, that they didn’t want her having sex with him, they and their families might tear and bite her to death.
    Wallen’s realization, in the seventies, that rhesus females are the aggressors in sex had begun with a pattern he noticed in graduate school. At his university, pairs of adult monkeys—one female, one male—were observed in ten-by-eight-foot cages. At a lab in Britain whose work he read about, the cages were markedly smaller. On both sides of the ocean, the females had their ovaries removed; the scientists were tallying the copulations of the rhesus in the absence of ovarian hormones. And Wallen, who found himself contemplating the two sets of results against each other, was captivated by the fact that the couples in the tighter cages had a lot more sex. “So I pulled the literature on a range of similar tests that were done in different-sized cages, and the relationship was quite clear. In the smallest cages there was the most sex, in the largest ones there was the least, and the in-between ones had an in-between amount.”
    Soon Wallen arrived at Yerkes, and, watching the rhesus in the center’s broad compounds—habitats whose size came closer to natural conditions—he developed his thinking about the way the tight confines in many experiments had helped to mold the accepted vision of monkey sexuality: lessening the female role and distorting the truth.
    Put a male and female in a small cage, and no matter what the female’s hormonal state—no matter whether she had ovaries at all—the pair would have plenty of sex, in part, Wallen came to understand, because their proximity to each other mirrored the kind of stalking Deidrah was doing now. This sexual signaling, created by the cramped dimensions, stirred the males to mount. The males appeared to be the initiators of the species. But put rhesus in a less artificial situation, and sex