Sex at Dawn: The Prehistoric Origins of Modern Sexuality (40 page)

What did Chivers find? Gay or straight, the men were predictable. The things that turned them on were what you’d expect. The straight guys responded to anything involving naked women, but were left cold when only men were on display. The gay guys were similarly consistent, though at 180 degrees. And both straight and gay men indicated with the keypad what their genital blood flow was saying. As it turns out, men
can
think with both heads at once, as long as both are thinking the same thing.

The female subjects, on the other hand, were the very picture of inscrutability. Regardless of sexual orientation, most of them had the plethysmograph’s needle twitching over just about everything they saw. Whether they were watching men with men, women with women, the guy on the beach, the woman in the gym, or bonobos in the zoo, their genital blood was pumping. But unlike the men, many of the women reported (via the keypad) that they weren’t turned on. As Daniel Bergner reported on the study in
The New York Times,

“With the women … mind and genitals seemed scarcely to belong to the same person.”4 Watching both the lesbians and the gay male couple, the straight women’s vaginal blood flow indicated more arousal than they confessed on the keypad.

Watching good old-fashioned vanilla heterosexual couplings, everything flipped and they claimed
more
arousal than their bodies indicated. Straight or gay, the women reported almost no response to the hot bonobo-on-bonobo action, though again, their bodily reactions suggested they kinda liked it.

This disconnect between what these women experienced on a physical level and what they consciously registered is precisely what the theory of differential erotic plasticity predicts. It could well be that the price of women’s greater erotic flexibility is more difficulty in knowing—and, depending on what cultural restrictions may be involved, in accepting—what they’re feeling. This is worth keeping in mind when considering why so many women report lack of interest in sex or diffaculties in reaching orgasm.*

If you aren’t confused already, consider that research psychiatrist Andrey Anokhin and his colleagues found that erotic images elicit significantly quicker and stronger response in women’s brains than either pleasant or frightening images without erotic content. They showed 264 women a randomly ordered collection of images ranging from snarling dogs to water skiers to semi-naked couples getting hot and heavy. The women’s brains responded about 20 percent faster to the erotic images than to any others. With men this eager responsiveness was expected, but the results among the supposedly less visual, less libidinous women surprised the researchers.5

The female erotic brain is full of such surprises. Dutch researchers used positron emission tomography (PET) to scan the brains of thirteen women and eleven men in the throes of orgasm. While the brevity of the male orgasm made reliable readings difficult to get, the heightened activity they found in the secondary somatosensory cortex (associated with genital sensation) was what they’d expected. But the women’s brains left the researchers befuddled. It seems the female brain goes into standby mode at orgasm. What little increase in cerebral activity the ladies’ brains exhibited was in the primary somatosensory cortex, which registers the presence of sensation, but not much excitement about it. “In women the primary feeling is there,” one of the researchers said, “but not the marker that this is seen as a big deal. For males, the touch itself is all-important. For females, it is not so important.”6

Every woman knows her menstrual cycle can have profound effects on her eroticism. Spanish researchers confirmed that women experience greater feelings of attractiveness and desire around ovulation, while others have reported that women find classically masculine faces more attractive around ovulation, opting for less chiseled-looking guys when not fertile.7 Since the birth control pill affects the menstrual cycle, it’s not surprising that it may affect a woman’s patterns of attraction as well. Scottish researcher Tony Little found women’s assessment of men as potential husband material shifted if they were on the pill. Little thinks the social consequences of his finding may be immense: “Where a woman chooses her partner while she is on the Pill, and then comes off it to have a child, her hormone-driven preferences have changed and she may find she is married to the wrong kind of man.”8

Little’s concern is not misplaced. In 1995, Swiss biological researcher Claus Wedekind published the results of what is now known as the “Sweaty T-shirt Experiment.” He asked women to sniff T-shirts men had been wearing for a few days, with no perfumes, soaps, or showers. Wedekind found, and subsequent research has confirmed, that most of the women were attracted to the scent of men whose major histocompatibility complex (MHC) differed from her own.9

This preference makes genetic sense in that the MHC

indicates the range of immunity to various pathogens.

Children born of parents with different immunities are likely to benefit from a broader, more robust immune response themselves.

The problem is that women taking birth control pills don’t seem to show the same responsiveness to these male scent cues. Women who were using birth control pills chose men’s T-shirts randomly or, even worse, showed a preference for men with similar immunity to their own.10

Consider the implications. Many couples meet when the woman is on the pill. They go out for a while, like each other a lot, and then decide to get together and have a family. She goes off the pill, gets pregnant, and has a baby. But her response to him changes. There’s something about him she finds irritating—something she hadn’t noticed before. Maybe she finds him sexually unattractive, and the distance between them grows. But her libido is fine. She gets flushed every time she gets close enough to smell her tennis coach. Her

body, no longer silenced by the effects of the pill, may now be telling her that her husband (still the great guy she married) isn’t a good genetic match for her. But it’s too late.

They blame it on the work pressure, the stress of parenthood, each other….

Because this couple inadvertently short-circuited an important test of biological compatibility, their children may face significant health risks ranging from reduced birth weight to impaired immune function.11 How many couples in this situation blame themselves for having “failed” somehow?

How many families are fractured by this common, tragic, undetected sequence of events?12

Psychologist Richard Lippa teamed up with the BBC to survey over 200,000 people of all ages from all over the world concerning the strength of their sex drive and how it affects their desires.13 He found the same inversion of male and female sexuality: for men, both gay and straight, higher sex drive increases the specificity of their sexual desire. In other words, a straight guy with a higher sex drive tends to be more focused on women, while higher sex drive in a gay guy makes him more intent on men. But with women—at least nominally straight women—the
opposite
occurs: the higher her sex drive, the more likely she’ll be attracted to men
and
women. Lesbians showed the same pattern as men: a higher sex drive means more women-only focus. Perhaps this explains why nearly twice as many women as men consider themselves bisexual, while only half as many consider themselves to be exclusively gay.

Those who claim this just means men are more likely to be repressing some universal human bisexuality will have to consider sexologist Michael Bailey’s fMRI scans of gay and straight men’s brains while they viewed pornographic photos.

They reacted as men tend to do: simply and directly. The gay guys liked the photos showing men with men, while the straight guys were into the photos featuring women. Bailey was looking for activation of the brain regions associated with inhibition, to see whether his subjects were denying a bisexual tendency. No dice. Neither gay nor straight men showed unusual activation of these regions while viewing the photos. Other experiments using subliminal images have generated similar results: gay men, straight men, and lesbians all responded as predicted by their stated sexual orientation, while nominally straight women (“I contain multitudes”) responded to just about everything. This is just how we’re wired, not the result of repression or denial.14

Of course, signs of repression aren’t hard to find in sex research. There’s plenty. For example, one of the long-standing mysteries of human sexuality has been that heterosexual men tend to report having more sexual encounters and partners than heterosexual women do—a mathematical impossibility. Psychologists Terry Fisher and Michele Alexander decided to take a closer look at people’s claims regarding age of first sexual experience, number of partners, and frequency of sexual encounters.15 Fisher and Alexander set up three different testing conditions: 1. The subjects were led to believe their answers might be seen by the researchers waiting just outside the room.

2. The subjects could answer the questions privately and anonymously.

3. The subjects had electrodes placed on their hand, arm, and neck—believing themselves (falsely) to be hooked up to a lie detector.

Women who thought their answers might be seen reported an average of 2.6 sexual partners (all the subjects were college students younger than twenty-five). Those who thought their answers were anonymous reported 3.4 partners, while those who thought their lies would be detected reported an average of 4.4 partners. So, while women admitted to 70 percent more sexual partners when they thought they couldn’t fib, the men’s answers showed almost no variation. Sex researchers, physicians, and psychologists (and parents) need to remember that women’s answers to such questions may depend on when, where, and how the question is asked, as well as who’s asking.

If it’s true that women’s sexuality is much more contextual than most men’s, we might need to reconsider a lot of what we think we know about female sexuality. In addition to the distortions created by the age bias we discussed earlier (are twenty-year-olds representative?), how useful are the responses of women answering questions in a cold classroom or laboratory setting? How would our understanding of female sexuality be different if George Clooney distributed the questionnaires by candlelight and collected them after a glass of wine in the Jacuzzi?

Sexologist Lisa Diamond spent over a decade studying the ebb and flow of female desire. In her book
Sexual Fluidity,
she reports that many women see themselves as attracted to specific
people,
rather than to their gender. Women, in Diamond’s view, respond so strongly to emotional intimacy that their innate gender orientation can easily be overwhelmed. Chivers agrees: “Women physically don’t seem to differentiate between genders in their sex responses, at least heterosexual women don’t.”

Apparently, many women see the
Mona Lisa
looking back at them from the mirror.

What are the practical effects of this crucial difference in erotic plasticity? To start with, we’d expect to find far more transitory, situational bisexual behavior among women than among men. Various studies of heterosexual couples engaging in group sex or “swinging” agree that it is common for women to have sex with other women in these situations but that men almost never engage with men. Additionally, while we’d be the last to suggest popular culture is a reliable indicator of innate human sexuality, it’s probably significant that women kissing women has quickly become accepted as mainstream behavior while depictions of men kissing each other on television or films remains unusual and controversial. Most women presumably wake up the morning after their first same-sex erotic experience more interested in finding some coffee than in conducting a panicked reassessment of their sexual identity. The essence of sexuality for most women seems to include the freedom to change as life changes around them.

There is, after all, a liberating simplicity in Mona Lisa’s complexity, which Freud seems to have missed. The answer to his question couldn’t be simpler, yet it contains multitudes.

What does woman want? It depends.

* This disconnect is also relevant to the research on jealousy we discussed in Chapter 10.

CHAPTER TWENTY-ONE

The Pervert’s Lament

Paraphilias are not universally present in human societies,
their incidence could be greatly reduced if tolerance and
education in sexual matters were more widespread. This is a
most important but socially sensitive area of sex research.

ALAN DIXSON1

While many women are freed by their erotic flexibility, men can find themselves trapped by the rigidity of their sexual response, like the male sheep and goats mentioned earlier.

Once determined, male eroticism tends to retain its contours throughout life, like concrete that has set. Consequently, the theory of erotic plasticity predicts that paraphilias (abnormal sexual desires and behaviors) should be far more prevalent in men than in women who would presumably be more responsive to social pressures and find it easier to abandon previous turn-ons or ignore unseemly urges. Nearly every source of evidence supports this prediction. Most researchers and therapists agree that these unusual sexual hungers are almost exclusively seen in males, appear to be related to early imprinting, and are difficult, if not impossible, to alter once boyhood impressions have hardened into adult yearnings.