What Do Women Want

does a woman want?”
    W hile they watched the clips of erotica, Chivers’s subjects didn’t just wear a plethysmograph; they also held a keypad. On this, they rated their own feelings of arousal. So Chivers had physiological and self-reported—objective and subjective—scores. They hardly matched at all. All was discord. And this dissonance resonated loudly with findings from other researchers.
    Women with women, men with men, men with women, lone men or women masturbating—Chivers’s objective numbers, tracking what’s technically called vaginal pulse amplitude, soared no matter who was on the screen and regardless of what they were doing, to each other, to themselves. Lust was catalyzed; blood flow spiked; capillaries throbbed indiscriminately. The strength of the pulsings did hold a few distinctions, variations in degree, one of them curious: the humping bonobos didn’t spur as much blood as the human porn, but with an odd exception. Among all women, straight as well as gay, the chiseled man ambling alone on the beach—an Adonis, nothing less—lost out to the fornicating apes. What to make of such strangeness?
    There was some further discrimination on the part of the lesbians. Over the series of studies Chivers did—to be sure her data were no fluke—they were a little selective; amplitude leapt more during videos starring women. Yet the lesbians’ blood rushed hard during scenes of gay male porn. When Chivers analyzed the evidence, transmitted from vaginal membranes to sensor to software, when she set it out in graphs of vertical bars, the female libido looked omnivorous.
    The keypad contradicted the plethysmograph, contradicted it entirely. Minds denied bodies. The self-reports announced indifference to the bonobos. But that was only for starters. When the films were of women touching themselves or enmeshed with each other, the straight subjects said they were a lot less excited than their genitals declared. During the segments of gay male sex, the ratings of the heterosexual women were even more muted—even less linked to what was going on between their legs. Chivers was staring at an objective and subjective divide, too, in the data from the lesbians: low keypad scores whenever men were having sex or masturbating in the films.
    She put heterosexual and homosexual males through the same procedure. Strapped to their type of plethysmograph, their genitals spoke in ways not at all like the women’s—they responded in predictable patterns she labeled “category specific.” The straight men did swell slightly as they watched men masturbating and slightly more as they stared at men together, but this was dwarfed by their physiological arousal when the films featured women alone, women with men, and, above all, women with women. Category specific applied still more to the gay males. Their readings jumped when men masturbated, rocketed when men had sex with men, and climbed, though less steeply, when the clips showed men with women. For them, the plethysmograph rested close to dead when women owned the screen.
    As for the bonobos, any thought that something acutely primitive in male sexuality would be roused by the mounting animals proved wrong. The genitals of both gay and straight men reacted to these primates the same way they did to the landscapes, to the pannings of mountains and plateaus. And with the men, the objective and subjective were in sync. Bodies and minds told the same story.
    How to explain the conflict between what the women claimed and what their genitals said? Plausible reasons swirled. Anatomy, Chivers thought, might be one factor. Penises extend, press against clothes. Visibly they shrink and shrivel. Boys grow up with a perpetual awareness; male minds are used to being fed information from their groins. A sexual loop between body and cognition, each affecting the other, develops; it runs fast and smooth. For women, more covert architecture might make the messages less clear, easier to miss.
    But were the women either consciously diminishing or unconsciously blocking out the fact that a vast scope of things stoked them—stoked them instantly—toward lust?
    The discord within Chivers’s readings converged with the results of a study done by Terri Fisher, a psychologist at Ohio State University, who asked two hundred female and male undergraduates to complete a questionnaire dealing with masturbation and the use of porn. The subjects were split into groups and wrote their