The Female Brain (14 page)

Bad past experiences can start to occupy a woman’s brain circuits, causing feelings of shame, awkwardness, or lack of safety. Twenty-eight-year-old Julie came to see me reporting she was unable to have an orgasm. She finally revealed that she had been molested by her uncle when she was a child and that the experience had made her dislike sex. She felt incredibly anxious when she had sex—even with her devoted, loving fiancé. Like Julie, four out of ten girls have had some kind of sexually upsetting experience in childhood that continues to occupy their brains with worries during adult sexual encounters—not being able to reach orgasm is one of the most common symptoms. Julie improved in her enjoyment of sex after getting both sex therapy and trauma therapy. Several months later she called me to report she’d had her first orgasm.

Especially for women, both biological and psychological factors influence arousability. Multitasking women end up having more distractions, which occupy their brain circuits and get in the way of sexual desire. Three months after she took a new job that required long hours, another patient of mine began having trouble reaching orgasm. She didn’t have any downtime to relax with her husband, and she began faking orgasms to keep from hurting his ego. The worries and tension of her new job were interfering with her ability to relax, feel safe, and allow her amygdala to deactivate.

The interference of worry and stress with sexual satisfaction may also be one reason women like vibrators. A vibrator applied to the clitoris can often provide a faster, easier orgasm. You don’t have to worry about the relationship, the guy’s ego, whether he’ll come too soon, or how you look in bed. Another patient of mine—divorced and in her forties—got so used to her vibrator that when she did become involved with a man again, she found he just wasn’t doing as good a job as her mechanical device. Finally, she took drastic measures—she buried her vibrator in the backyard in order to force herself to get used to a real penis.

A woman needs to be put in the mood. Before sex, there has to be a soothing and smoothing of the relationship, and she has to be able to stop being annoyed with him. Anger at one’s partner is one of the most common reasons for sexual problems. Many sex therapists say that, for women, foreplay is everything that happens in the twenty-four hours preceding penile insertion. For men, it’s everything that happens three minutes before. Since many parts of a woman’s brain are active at once, she must get into the mood by first relaxing and reconnecting positively with her partner. This is why she needs a good twenty-four hours to get in the mood, and why going on vacation is such an intense aphrodisiac. It allows her to unplug from daily life stress. So men, yes, bring out the flowers, chocolates, and sweet words—they work. A woman can’t be angry at her man and want to have sex with him at the same time. And women, tell your men that if they plan on criticizing you or starting a fight on the day they are hoping to get lucky, they should think again. They will have to wait for the twenty-four-hour clock to reset before you’ll be ready.

T
HE
F
UNCTION OF
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EMALE
O
RGASM

From an evolutionary perspective, male orgasm is no great mystery. It’s little more than a biologically simple ejaculation accompanied by an almost addictive incentive to seek out further sexual encounters. The theory goes that the greater the number of inseminations a male achieves, the better are his chances of having his genes represented in future generations. Women’s sexual climax is more complex and hidden—and can be easily faked. Women do not necessarily need to experience orgasm in order to conceive, though it helps.

Despite some scientists’ belief that there is no purpose in female orgasm, it actually works to keep a woman lying down after sex, passively retaining sperm and increasing her probability of conception. Not to mention that orgasm is intense pleasure, and anything that feels good makes you want to do it again and again—just what Mother Nature had in mind. Others have suggested that female orgasm evolved to create a stronger partnership between lovers, inspiring in women feelings of intimacy and trust toward mates. An orgasm communicates a woman’s sexual satisfaction with and devotion to a lover.

Many evolutionary psychologists have also come to view the female orgasm as a sophisticated adaptation that allows women to manipulate—even without their own awareness—which of their lovers will be allowed to fertilize her eggs. The quickened breath, moaning, racing heart, muscular contractions and spasms, and nearly hallucinatory states of pleasure that orgasm inspires may constitute a complex biological event with a functional design. Scientists believe orgasm may function as a “sperm competition,” through which women’s bodies and brains choose a winner.

The muscular contractions and uterine suction associated with women’s orgasm have long been known to pull the sperm through the cervical mucus barrier. In one published account of the strength of the orgasmic suction into the cervix, a doctor reported that a patient’s uterine and vaginal contractions during sex with a sailor had pulled off his condom. Upon inspection, the condom was found inside the tiny cervical canal. This means that the female orgasm can function to pull sperm closer to the egg. Scientists have discovered that when a woman climaxes any time between one minute before and forty-five minutes after her lover ejaculates, she retains significantly more sperm than if she does not have an orgasm. No orgasm means fewer sperm are sucked up into the cervix—the entry portal to the uterus, where the egg lies waiting. While a man worries about a woman’s satisfaction with him as a lover—out of fear that she will stray or not want to have sex with him again—orgasmic females may actually be up to something far more clever. With her orgasms, a woman is deciding which partner will sire her children. If Marcie’s Stone Age brain thinks John is sexy and good-looking enough to be a good genetic bet for her offspring, having an orgasm with him becomes serious business.

Biology has a way of winning out over our conscious minds by manipulating our reality to ensure evolutionary survival, so a woman’s unconscious brain circuits will choose the best-looking guy, since he will give her bigger orgasms. Behavioral ecologists have also noted that female animals—from scorpion flies to barn swallows—prefer males with high degrees of bilateral body symmetry, which means that both sides of the body match. The reason perfectly matching body parts may be important is that the translation of genes into parts of the body can be perturbed by disease, malnutrition, or genetic defects. Bad genes or disease can cause deviation from bilateral symmetry in traits such as hands, eyes, and even birds’ tail feathers, which are the visual features on which our female counterparts in the animal kingdom make their choices. Females want the best-looking guy to sire their offspring as well. The best males—those whose immune systems are strong, and who are healthy providers—develop with higher body symmetry. Females who choose symmetrical suitors are securing good genes for their offspring.

Humans share this preference. In studies, women consistently choose men whose faces, hands, shoulders, and other body parts are more symmetrical. This is not a matter of mere aesthetics. A large and growing body of medical literature documents that symmetrical people are physically and psychologically healthier than their less symmetrical counterparts. So if the guy you’re dating is a little funny looking to you and you are put off, it may be nature signaling you about the quality of his genes. John just happened to be the best-looking man Marcie had ever dated, so maybe that had something to do with her desire to have him sire her children.

Scientists have reasoned that if women’s orgasms are an adaptation for securing good genes for their offspring, then women should report more orgasms with good-looking, symmetrical mates. At the University of Albuquerque, researchers observed eighty-six sexually active heterosexual couples. Their average age was twenty-two, and the couples had been living together for two years—so trusting relationships had already been established. The researchers had each person privately—and anonymously—answer questions about his or her sexual experiences and orgasms. They then took photographs of each person’s face and used a computer to analyze the features for symmetry. They also measured various body parts—the width of elbows, wrists, hands, ankles, feet, leg bones, and the length of the second and fifth fingers.

Indeed, the hypothesized relationship between male symmetry and female orgasm proved to be true. Reports provided by the women—and their lovers—indicated those whose partners were the most symmetrical enjoyed a significantly higher frequency of orgasms during sexual intercourse than those with less symmetrical mates.

Handsome men know this firsthand. Studies show that symmetrical men have the shortest courtships before having sexual intercourse with the women they date. They also invest the least time and money on their dates. And these handsome guys cheat on their mates more often than do guys with less well-balanced bodies. This is not what we women would like to believe. Instead, we like the bonding hypothesis, which says that women with kind, caring mates will have the most orgasms. But the reality is that men may just come in two different categories. There are the ones for hot sex and the ones for safety, comfort, and child rearing. Women are constantly longing for both wrapped into one package, but sadly, science shows that this may be wishful thinking.

Of course, no one is perfectly symmetrical, but we all do rate those with the greatest symmetry as being the best looking. To the researchers’ surprise, women’s romantic passion toward their mates did not increase the frequency of orgasm. Not only that but even though conventional wisdom holds that birth control and protection from disease increase orgasm rates among women—supposedly because they allow women to feel more relaxed during intercourse—no relationship emerged between female orgasm and the use of contraception. Instead, only how good looking the guy was correlated with a high frequency of female orgasm during copulation. After all, our brains are built for survival in the precontraceptive Stone Age. In evolutionary terms, condoms and the pill are just flashes in the pan—too recent to have changed the way we experience emotions or sex.

T
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B
IOLOGY OF
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EMALE
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NFIDELITY

Mother Nature uses everything at her disposal to make sure couples get together and make babies, and this requires that sex happen at the right time of the month. Odors, for instance, are strongly linked to emotions, memory, and sexual behavior. Women’s noses and brain circuits are particularly sensitive just before ovulation—not just to ordinary scents but also to the imperceptible effects of male pheromones. Pheromones are social chemicals that humans and other animals release into the air from their skin and sweat glands. They are found in male body sweat. Pheromones alter brain perceptions and emotions and influence desires—such as desire for sex. The brain changes its odor sensitivity as the estrogen surge leads up to ovulation. A small quantity of a pheromone is all it takes; the amount released in one one-hundredth of a drop of human sweat is enough to have a powerful effect. No wonder the perfume industry is going crazy trying to add this stuff to perfume and aftershave.

But what the scent industry doesn’t know is that this effect depends on the day and even the hour of the menstrual cycle. When preovulatory women, for instance, who are at the peak of their monthly fertility, are exposed to a pheromone from male sweat glands called androstadienone
(an-dro-sta-DIE-en-own
, a close cousin of androstenedione,
an-dro-STEEN-die-own
, the major androgen made by the ovaries), within six minutes their mood brightens and their mental focus sharpens. These airborne pheromones keep women from getting into a bad mood for hours afterward. Beginning at puberty, only female brains, not male brains, are able to detect the androstadienone pheromone, and they’re sensitive to it only during certain times of the month. It may be that androstadienone works on the emotions of females at their monthly reproductive peak to pave the way for social—and reproductive—interactions. It is interesting that Marcie mentioned to me during her first appointment that something about John’s smell captivated her.

Using the body odor of men and the noses of women, Jan Havlicek of Charles University in Prague has hatched a controversial theory about pheromones and the female brain. He found that ovulating women who already have partners preferred the smell of other more dominant men but that single women showed no such preference. Havlicek argues that his findings support the theory that single women want nurturing men who will help raise a family. But once the home is secured, they have the biological urge to sneak around with men who have the best genes. Studies of mating patterns in species of birds once thought to partner for life showed that up to 30 percent of the baby birds were sired by males other than the ones taking care of them and living with their mothers.

Yet another blow to the myth of female fidelity is the dirty little secret in human genetic studies—up to 10 percent of the supposed fathers researchers have tested are not genetically related to the children these men feel certain they fathered. Ethical constraints prevent scientists from revealing this detail to anyone. Why does this happen? Is the female brain more likely to trigger an orgasm and conceive with a male who isn’t her usual mate? Having an orgasm with a particularly desirable partner is thought to confer a reproductive advantage. Since a woman’s orgasm sucks the sperm high up into the female reproductive tract, an orgasm with an enticing male gives a greater likelihood that the sperm will make it to the egg. This increased chance of conception with a sexy partner might be why women typically are more attracted to other men on the second week of their menstrual cycle—right before ovulation—their most fertile and flirtatious time of the month.