What Do Women Want

deli slicer, which could be set to the width of a micron, Pfaus was nowhere near to completely capturing the interplay of neurotransmitters. But a third type of transmitter essential to eros, he said, are the opioids, which surge with orgasm and also spike in tandem with dopamine’s drive, so that glimpsing a lover’s muscular chest or reading a paragraph of erotica offer a minor wave of opioid bliss. Describing this pleasure, he talked about the opioids’ most potent varieties, the products of poppies: morphine, heroin. Send these drugs into the brain and satisfaction is so thorough—so much stronger than serotonin’s well-being—that inertia takes hold. Both the executive region and the lustful center are quelled; direction and drive are nullified. In the less potent forms supplied by orgasm, the opioid rush lulls to lesser degrees. Meanwhile, a paradoxical process kicks in. Even while the opioids are quieting motivation, they are preparing the brain to be motivated again by somehow stoking the dopamine system. Orgasms simultaneously subdue the brain and teach it to seek more climaxes. Maybe even regardless of orgasm—for Pfaus couldn’t be sure his female rats were climaxing—he saw the power of opioid bliss in his lab. Infuse female rats with a chemical that blocks this ecstasy, and they lose their desire to have sex at all.
    Pfaus, whose hoop earring cast a gleam, whose mind bounced always between rodents and humans, translated this finding into a few words of advice: men had better perform; they’d better learn, they’d better deliver, and they’d better keep on delivering.
    Not that this would solve men’s problems, not that it should calm their worries. One morning he lectured his undergraduates on the Coolidge effect, a standard in sexuality textbooks, an expression of what Pfaus scorned as evolutionary psychology’s “shtick.” The Coolidge effect comes from a tale that goes like this: One day President Coolidge and his wife were visiting an experimental government farm. They took separate tours. When Mrs. Coolidge came to the chicken yard she noticed the rooster’s frequent mating and asked the attendant how often this went on. “Dozens of times each day,” he informed her, to which she replied, “Please tell that to the president when he comes by.” The attendant did as she requested when the president arrived. “Same hen every time?” the president asked. “Oh, no,” the man answered, “different hen every time.” And the president said, “Please tell that to Mrs. Coolidge.”
    The tale is used to hammer home the principle that male lust feeds on multiple partners. Pfaus mocked the faith that this is somehow less so for females. Rodent females, he informed his undergrads, do more hopping and darting to score with new mates. And they dip their spines deeper, so the new male has an easier time thrusting in.
    D uring one of our talks, Pfaus swerved from the evidence he’d accumulated; he careened down a road of speculation. “When this generation of young people is fully studied,” he said, words gathering speed, “we’re going to see more supposedly male-like behavior, more women picking up men, more women getting laid and leaving, having sex without waiting to bond, more girls up in their rooms at their computers clicking on porn and masturbating before they get started on their homework.”
    It wasn’t clear which age group he was thinking about, whether he meant girls who were now twelve or women who were now twenty-four, and it wasn’t clear how he explained the unfettering he believed was underway, though it seemed to have partly to do with the Internet. Were there any concrete signs, I wondered, that the trend he imagined was real? Were girls and women staring more and more at the X-rated? Was their porn-surfing nearing that of men? There were only scattered answers, slivers of evidence. The most credible came from Nielsen, the consumer tracking company, in a report that one in three online porn users was female—four years earlier, the figure had been one in four. And porn-addiction counselors were quoted in the press saying that their ratios of female clients were rising. Yet the most vivid clue was probably James Deen’s fan base.
    Deen—who’d chosen his name and its spelling himself—was a porn star who’d shot two thousand scenes over the last eight years, scenes in which a delivery man is asked inside for a blow job, in which a principal teaches a