Why Women Have Sex (41 page)

The physical pleasure of sex is one of the best ways for me to relieve menstrual cramping. I’ve had sex for this reason many times as a comfort-based motivation.

—heterosexual woman, age 47

During orgasm, a woman’s uterus contracts, and in the process, those excess (some might say “evil”) cramp-causing prostaglandins are used up—relieving cramps. An added benefit is that having sex during menstruation can also lead to a shorter menstrual cycle. Some women report their period comes to an abrupt end within a day of having intercourse, leading them to wonder whether intercourse somehow “jammed it all up there until the next month.” To the contrary, the increased number of uterine contractions during orgasm helps expel menstrual blood more quickly—ending the menstrual period more efficiently. In the mid-1960s, the sex researchers William Masters and Virginia Johnson directly observed women having orgasms in the laboratory in order to document the physiological changes that took place. With the help of a speculum device, they could actually see the pressure of sex causing
menstrual fluid to squirt out of the cervical canal during the final stages of orgasm.

Sex can also decrease the chances that a woman will suffer from endometriosis, a common gynecological condition that occurs when uterine tissue grows outside the uterus in areas such as the ovaries or fallopian tubes. This growth can cause pain during sex, pelvic pain, and sometimes infertility. Researchers at Yale University School of Medicine found that women who regularly engaged in sexual intercourse or masturbation during menstruation were one and a half times less likely to develop endometriosis than women who abstained from sexual activities during their periods. (Curiously, tampon use also decreases a woman’s chances of having endometriosis.)

In a way, sexual activity serves as the vagina’s maid service. Menstrual blood often contains bits of endometrial tissue that can flow backward into the pelvic area. This phenomenon, called “retrograde menstruation,” increases a woman’s risk of developing endometriosis, so having intercourse during menstruation could decrease the risk by sweeping the vagina clear of menstrual debris. Orgasm, either through intercourse or masturbation, could further decrease the risk of endometriosis because the orgasmic contractions can help push menstrual debris out of the uterus. On a related note, in the same Yale School of Medicine study, women who used only menstrual pads were more than twice as likely to develop endometriosis as were women who used only tampons. This suggests that tampons remove menstrual fluid and debris more efficiently than pads. Douching, either when menstruating or not, was unrelated to endometriosis risk.

So, sex during menstruation can relieve cramps, shorten the menstrual cycle, and decrease the risk of endometriosis. Clearly, scientific evidence was not available when Pliny the Elder made
his
list of the consequences of intimacy during menstruation. According to Pliny, contact with menstrual blood turned new wine sour, rendered crops barren, dulled the edge of steel and the gleam of ivory, drove dogs mad, and even caused tiny ants to turn in disgust from grains of corn that tasted of menstrual blood.

[Sex] is a stress reliever, and let’s face it, most of the time men don’t care why, they’re just happy to help along.

—predominantly heterosexual woman, age 22

Everyone knows how feeling angry or anxious can change how we experience things. Negative thoughts can occupy, even take over, our minds and prevent us from noticing pleasant things in the immediate environment. Sometimes, as we’ve seen, in sexual situations the negative thoughts are so distracting that they prevent us from focusing on sexually arousing cues such as the pleasurable sensations of a partner’s touch or positive emotions toward our mates. Masters and Johnson termed this “spectatoring” because instead of being fully engaged in the sex act, it is as if the sexual participant is a “third person,” removed psychologically from the experience. Obviously, if you are thinking about what a jerk your boss was that day, or you are lying there making a list of the forty-two things you need to do by tomorrow rather than becoming aware of and turned on by any genital response, it is not going to help you to become sexually aroused or have an orgasm. This is the side of stress that sometimes causes women not to enjoy sex or not to want to have sex.

But there is also a whole host of physical changes that occur in the body during a stressful situation that lead many women to
want
to engage in sexual activity. When a person is feeling stressed out, the branch of the nervous system known as the sympathetic nervous system, or SNS, becomes activated. The SNS is responsible for increasing heart rate and blood pressure, for stimulating sweat to get rid of excess water in our bodies, for relaxing the bladder muscles (which is why some people or animals urinate uncontrollably when they are frightened), for decreasing digestion, and for stimulating the liver to release glucose for energy. SNS activation also releases norepinephrine, a brain chemical that has a molecular structure similar to the stimulant amphetamine. All of these changes speed up the body so that we can react quickly when we are confronted with a physical threat or a compromising situation, the quintessential “fight or flight” response. The SNS is meant to be active only during a limited critical period—until we deal with the stressor by either fighting back or
running away. If the activation persists because, for whatever reason, we are unable to resolve the stress efficiently, then it becomes distracting psychologically and makes us feel extremely uncomfortable physically.

No one would dispute that it is hard to relax or to concentrate on work when you are sweating and shaking and your heart is pounding at 110 beats per minute. Prolonged activation of the SNS can lead to all sorts of cardiovascular, immune system, and nervous system disorders. Many people who frequently experience excess nervous system arousal take beta-blockers or other anti-anxiety drugs, such as Clonazapam or Xanax, to get rid of the symptoms. In our study, some women reported that having sex can also do the trick:

There have been days when life is difficult, usually because of work-related stress, and you just want to let out some steam. So, coming home and fucking passionately really is a good release under those circumstances.

—heterosexual woman, age 44

I suppose it is more accurate to say that I had sex to relieve aggression brought on by boredom. Sometimes when I’m with my partner I recognize that I’m feeling irritable, and that leads to aggressiveness. Usually it is just because I am feeling bored. So, I have sex ’cause it’s easier than fighting. Plus it gives me something to do.

—predominantly heterosexual woman, age 27

On occasion, when I am feeling frustrated and angry I need a physical outlet for this extra energy. I have found that having sex is a positive way to deal with these negative emotions and can calm me down. Other forms of physical exertion (e.g., exercise) can have a similar effect, but don’t always.

—heterosexual woman, age 23

For a lot of women in our study, having sex when they were stressed also helped clear their minds so that they could focus better on their goals, or approach a problem more objectively:

School sometimes really frustrates me. Whenever I have a difficult problem that seems almost impossible to solve, I’ll take a break from it and have sex with my boyfriend. Usually afterward I find it easier to solve the problem because I’ve taken a break from it and gotten out my frustrations by having sex.

—heterosexual woman, age 19

And for some, this applied to having sex after a fight with their partner:

I was in a long-term relationship at a very young age. . . . I think that I believed that sex after fighting made everything better. Honestly, it usually did, albeit briefly. . . .

—heterosexual woman, age 25

Having sex during or after a fight with one’s partner can sometimes help resolve relationship differences. Because sex can release built-up anger and frustration, which in turn allows our bodies to return to normal levels of arousal, it can help clear our minds, at least temporarily, of the negative thoughts that caused the fight. While sex does not actually
solve
the underlying problem that triggered the fight, it can better equip women to confront a problem rationally instead of angrily and emotionally:

Make-up sex is always more passionate and fun. However, I find it does not solve everything. . . . [But] you can sort of just take all the emotions and bad energy and channel it into passion and lust and good things and you come out feeling a hundred times less stressed.

—heterosexual woman, age 24

For couples who have a strong foundation, having sex after a fight can also serve as a reminder of the commitment they truly feel toward each other. And, for all the reasons described in chapter 3 on love and emotional bonding, “make-up” sex can help people to reconnect.

Chronic stress of the human variety can wreak havoc on the body in many ways. Difficulty falling or staying asleep affects more than 20 million Americans—twice as many women as men. An even greater number of people experience occasional insomnia brought on by excitement or stress or from drinking too much caffeine or alcohol, favorite “home remedies” for dealing with stress shocks. Typical recommendations for people who have trouble sleeping include going to sleep and waking up at the same time each day; avoiding caffeine, nicotine, alcohol, and big meals late in the day; using your bed only for sleeping and sex; getting regular exercise; and keeping your bedroom dark, quiet, and cool.

The many testimonies from women in our study suggest that having sex should also be added to the list of sleep remedies:

Getting close to finishing my graduate degree I fought insomnia and stress. I was running to control these things, I was working hard, but I grew to also need the euphoria and ability to shut down my brain that orgasm brought, as well as the flood of endorphins that gave me enough peace to rest. I rarely had anyone near me at my beck and call, however, so often as not I would use a dildo or two to get myself off, which had the added advantage of being completely selfish [and] without guilt.

—predominantly heterosexual woman, age 29

If you follow this recommendation, one bit of advice: Highly active sex that gets your heart pumping can make a woman more energized than sleepy. So if you’re using sex as a sleep aid, you might consider saving “aerobic” sex for earlier in the day and pursue a more subdued “sleepy-time” sex.

Endorphins released during orgasm can help induce sleep by relaxing the mind and the body. But probably more important, during orgasm the hormone prolactin is released—and there is a strong link between that hormone and sleep. Prolactin levels are naturally higher when we sleep, and studies conducted in animals show that prolactin injections make animals intensely sleepy. Prolactin release has also been
associated with feelings of satiety. In men, prolactin is partly responsible for the refractory period. In women, prolactin does not have the same inhibitory effect as it does in men, which may explain why so many more heterosexual women than men seem to complain that their partners fall asleep right after sex.

Interestingly, research has shown that there is a 400 percent greater increase in prolactin from orgasms that occur from intercourse than from masturbation. From an evolutionary perspective, this makes sense: If orgasms from intercourse make women feel more fulfilled than orgasms from masturbation, then women would be more inclined to engage in partnered sex, which, unlike masturbation, can serve a direct reproductive function. To the extent that prolactin induces sleepiness in women, it would be more important that sleepiness occur following intercourse than masturbation as it would induce the woman to lie still, which could facilitate sperm transport to the egg.

Although sex can help rid a person of feelings of anxiety, anxiety can also enhance a woman’s genital sexual response. Some women in our study reported having sex because anxiety made them feel more “turned on”:

When I am overstressed or worried, I often respond by becoming increasingly horny. . . .

—heterosexual woman, age 20

Oh, how I loved my [husband]. We were married sixty-four years and never spent a day apart all those years. We had so much fun. Oh, sure, we fought, but the makin’ up part was fun too!

—heterosexual woman, age 86

The effects of anxiety on sexual arousal have been measured using vaginal photoplethysmography technology, which was described in chapter 2. In one study, women watched a travel documentary that created no stress. Immediately afterward, they watched a film of a couple
engaging in foreplay, oral sex, and intercourse. On another occasion, the women watched a film designed to elicit an SNS response before watching a similar erotic film. Women showed much greater vaginal engorgement from the erotic films on the day they viewed the anxiety-evoking film first, even though there were no scenes in the anxiety films that could have provoked sexual thoughts in the women. Therefore, the most compelling explanation is that the SNS activation caused by the anxiety-evoking film increased the women’s sexual arousal.