Why Women Have Sex (44 page)
Read Why Women Have Sex Online
Authors: Cindy M. Meston,David M. Buss
Another way that sex could increase longevity is that moderate levels of sex (with a sexually healthy partner, of course) can boost immune system functioning. This might explain why some women in our study reported having sex simply to “keep healthy” or to “live longer.” Immunoglobulin A (IgA) is an antibody that binds to pathogens when they enter the human body. These antibodies help form a barrier against diseases such as the flu or the common cold. Levels of IgA, which is found in saliva and mucosal linings, indicate how robust our immune systems are. Studies show that exposure to enjoyable music or to pets can significantly increase IgA levels within a very short period of time—twenty to thirty minutes. Romantic relationships can also have an enormous impact on immune function—both good and bad. Overall, married people experience less disease and have better outcomes after various disease diagnoses than do single people. But men and women in poor relationships show substantial deficits in immune function.
To examine whether how often a person has sex could also influence immune system functioning, psychologists Carl Charnetski and Francis Brennan asked 112 college students, most of whom were women, how often they had sex during the past month. They also collected saliva samples from all the participants to assess IgA levels. Students who had sex infrequently (less than once a week) had slightly higher levels of IgA than students who had completely abstained from sex. However, students who had sex regularly (once or twice a week) had 30 percent higher levels of IgA than all other students—suggesting better immune system function. It may be that frequent sex made the students more relaxed and
happy—both of which are known to increase IgA levels. The increase in opioid peptide release that occurs with orgasm may lead to increased immune system function.
The finding that was hard to explain was that students who had engaged in even more frequent sex—three or more times per week—had the lowest IgA levels of all students, lower even than the abstainers. This suggests there is an optimal frequency of sexual activity for keeping the body’s defenses strong. Studies show that a moderate level of opioid peptide release enhances the immune system, but one study found that too much opioid peptide release can actually suppress immune system functioning.
Finally, women in our study described other health benefits that motivated them to have sex. In addition to inducing sleepiness, prolactin causes stem cells in the brain’s smell center, the olfactory bulb, to develop new neurons. So, technically, sex can improve one’s sense of smell. Another side benefit to regular sex is that it can improve bladder control by working and strengthening the same muscles that are used during urination. And for postmenopausal women, regular sex can help prevent vaginal atrophy that is often a consequence of aging-related decreases in sex hormones. One study found that postmenopausal women who had sexual intercourse at least three times a month had less vaginal atrophy than those who had intercourse less than ten times per year. Having sex can increase the presence of estrogen and testosterone; a burst of the body’s own testosterone is thought to help fortify bones and muscles, and estrogen promotes healthy vaginal tissue, soft skin, and shiny hair. Perhaps this explains why Joan Crawford is quoted as once saying, “I need sex for a clearer complexion.”
Much to our amusement, several lesser-known men’s magazines and Web sites listed even more reasons why “women should have sex.” These included assertions such as that kissing stimulates salivation, which cleans “gunk” stuck between your teeth, and that sex can help your nose run so that you are not so stuffed up afterward. Although there may be evidence somewhere to support these claims, we aren’t convinced they are good selling points for motivating a woman to have sex. But more to the point, none of the women in our study mentioned even one of them.
hy women have sex is surely one of the most fascinating, complex, and enigmatic questions facing the psychology of human motivation. Throughout this book, we have explored many motives—from the frantic desperation to regain some measure of dignity after being spurned to the soaring heights of the consummation of true love; from the altruistic motive of boosting a partner’s self-esteem to the selfish motive of exacting revenge; from the thrill of adventure to the dark side of deception; from the mundane motive of relieving a headache to the spiritual aspiration to get closer to God.
Although for economy and clarity of communication, we have parsed the reasons why women have sex into discrete motivations, it’s important to acknowledge that what drives a woman to have sex is often more complex and multifaceted, containing varying combinations of motivations. A woman might have sex to gain status among her peer group
and
because she wonders what all the fuss is about. A woman might have sex because a prospective partner’s appearance ignites her desire
and
because she’s unhappy with her current relationship. A woman might have sex because she wants to relieve her own stress
and
boost
her lover’s self-confidence
and
become emotionally closer to her partner.
We must recognize too that women’s sexual motivations sometimes conflict with one another. A woman may crave the oxytocin rush of an orgasm on a first date, yet also be motivated to delay sex so as not to appear “too easy.” Another might be torn between her desire to have sex with an exciting new lover and her vow to fulfill her commitment of fidelity to her husband. A woman may even experience a conflict between a yearning to relinquish all control and feel the rush of sexual submission and her wish to take charge of the encounter and give full flower to her sexual power.
We have tried to examine the magnificent diversity of women’s sexual motivations through several theoretical lenses. One is placing women’s sexuality within an evolutionary perspective, framing it in the context of the bewildering variety of adaptive problems ancestral women have repeatedly confronted over eons of deep time. A second is physiological, which shows how features of hormones and brain chemicals, blood flow, and anatomy provide a foundation for women’s sexuality. A third is a clinical lens, providing insight into the difficulties women encounter as they grapple with and sometimes successfully solve the sexual concerns of desire, arousal, and orgasm. A fourth is psychological, tapping into the rapidly expanding reservoir of scientific knowledge about the mental states that affect women’s sexuality, and which in turn are altered by women’s sexual experiences. We hope that the unique confluence of these multiple lenses has revealed many more facets of women’s sexual motivation than would any single conceptual lens.
We also hope that beyond these theoretical lenses, the multiplicity of sexual motivation has sprung to life through the experiences directly and eloquently described by the women who graciously agreed to participate in our study. A woman recounting sex with her partner as “the fullest flower of the blossom of our love” may capture more of the true experience than the abstract triangular theory of love. The women who described suffering feelings of humiliation and degradation after being sexually deceived by a man brings the phenomenon of sexual exploitation to life more than our theoretical analysis of why sexual deception is
so prevalent in the human species. The woman who highlighted her ecstatic experience when a man who was a good dancer
literally danced while having sex
provides an illuminating complement to describing the importance of biomechanical efficiency and smooth motor movements in sexual attraction.
We learned much about human sexuality from the women in our study, and we hope that you have, too.
I
NTRODUCTION
For instance, penile erection monitors: Rosen, R. C., and Beck, J. G. (1988). | |
In the early 1970s, two doctors: Abrams, R. M., and Stolwijk, J. A. J. (1972). “Heat Flow Device for Vaginal Blood Flow | |
The survey itself was hosted: A small number of women elected to e-mail or mail their responses to us directly instead of using the online form. |
1. W
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Back in the 1930s: Brossard, J. (1932). “Residential Propinquity as a Factor in Marriage Selection,” | |
With alphabetical seating: Segal, M. W. (1974). “Alphabet and Attraction: An Unobtrusive Measure of the Effect of Propinquity in a Field Setting,” | |
One study found that: Saegert, S., Swap, W., and Zajonc, R. (1973). “Exposure, Context, and Interpersonal Attraction,” | |
Attraction increased as the number: Moreland, R. L., and Beach, S. (1992). “Exposure Effects in the Classroom: The Development of Affinity Among Students,” | |
The effect of mutual eye gaze: Williams, G. P., and Kleinke, C. L. (1993). “Effects of Mutual Gaze and Touch on Attraction, Mood, and Cardiovascular Activity,” | |
Participants again reported deep attraction: Huston, T. L., and Levinger, G. (1978). “Interpersonal Attraction and Relationships,” | |
As one woman said in her sexual memoir: Slater, L. (2008). “Overcome,” in P. Derrow (ed.), | |
Psychologist Daryl Bem sums it up: Bem, D. J. (1996). “Exotic Becomes Erotic: A Developmental Theory of Sexual Orientation,” | |
Indeed, in college classes: Buss, D. M. (2009). Unpublished data. | |
Using an instrument called: Herz, R. S., and Cahill, E. D. (1997). “Differential Use of Sensory Information in Sexual Behavior as a Function of Gender,” | |
The first clue came: Doty, R. L., et al. (1981). “Endocrine, Cardio-vascular, and Psychological Correlates of Olfactory Sensitivity Changes During the Human Menstrual Cycle,” | |
In a revealing study: Santos, P. S. C., et al. (2005). “New Evidence that the MHC Influences Odor Perception in Humans: A Study with 58 Southern Brazilian Students,” | |
University of New Mexico evolutionary psychologist: Garver-Apgar, C. E., Gangestad, S. W., et al. (2006). “MHC Alleles, Sexual Responsivity, and Unfaithfulness in Romantic Couples,” | |
In one study, men wore white cotton T-shirts: Thornhill, R., and Gangestad, S. W. (2008). | |
When women have extramarital affairs: Gangestad, S. W., and Thornhill, R. (1997). “The Evolutionary Psychology of Extra-Pair Sex: The Role of Fluctuating Asymmetry,” | |
One study found that frequent: Cutler, W. B., et al. (1980). “Sporadic Sexual Behavior and Menstrual Cycle Length in Women,” | |
Another study showed that women: Veith, J. L., et al. (1983). “Exposure to Men Influences Occurrence of Ovulation in Women,” | |
Dr. Winnifred Cutler, the director: Cutler, W. B., Friedmann, E., and McCoy, N. L. (1998). “Pheromonal Influences on the Sociosexual Behavior of Men,” | |
Men who indicated: Sugiyama, L. S. (2005). “Physical Attractiveness in Adaptationist Perspective,” in D. M. Buss (ed.), | |
Women prefer tall men: Buss, D. M., and Schmitt, D. P. (1993). “Sexual Strategies Theory: An Evolutionary Perspective on Human Mating,” | |
Women even take height: Scheib, J. E. (1997). “Female Choice in the Context of Donor Insemination,” in P. A. Gowaty (ed.), | |
In Western cultures, tall men: For summaries of these studies, see Ellis, B. J. (1992). “The Evolution of Sexual Attraction: Evaluative Mechanisms in Women,” in J. Barkow, L. Cosmides, and J. Tooby (eds.), | |
Most women show a distinct preference: Hughes, S. M., and Gallup, G. G. (2003). “Sex Differences in Morphological Predictors of Sexual Behavior: Shoulder to Hip and Waist to Hip Ratios,” | |
Potential rivals with a high shoulder: Dijkstra, P., and Buunk, B. P. (2001). “Sex Differences in the Jealousy-Evoking Nature of a Rival’s Body Build,” | |
One study compared the muscularity: Frederick, D. A., and Haselton, M. G. (2007). “Why Is Male Muscularity Sexy? Tests of the Fitness Indicator Hypothesis,” | |
After viewing repeated: Olivardia, R. S. (2001). “Mirror, Mirror on the Wall . . . Are Muscular Men the Best of All? The Hidden Turmoils of Muscle Dysmorphia,” | |
“feels like Clark Kent”: Frederick, D. A., Buchanan, G. M., et al. (2007). “Desiring the Muscular Ideal: Men’s Body Satisfaction in the United States, Ukraine, and Ghana,” | |
Women’s sexual desires for testosterone-fueled: Penton-Voak, I. S., Perrett, D. I., et al. (1999). “Female Preference for Male Faces Changes Cyclically,” Nature 399: 741–42. Roney, J. R., and Simmons, Z. L. (2008). “Women’s Estradiol Predicts Preferences for Facial Cues of Men’s Testosterone,” | |
They are more likely to be the risk-taking: Jonason, P. K., Li, N. P., et al. (2009). “The Dark Triad: Facilitating Short-Term Mating in Men,” | |
They interpret this cultural difference: Penton-Voak, I. S., Jacobon, A., and Trivers, R. (2004). “Population Differences in Attractiveness Judgments of Male and Female Faces: Comparing British and Jamaican Samples,” | |
They discovered that the infants: Langlois, J. H., et al. (1990). “Infants’ Differential Social Responses to Attractive and Unattractive Faces,” | |
Attractiveness is moderately linked: Langlois, J. H., Kalakanis, L., et al. (2000). “Maxims or Myths of Beauty? A Meta-Analytic and Theoretical Review,” | |
The first scientific evidence: Puts, D. A., Gaulin, S. J. C., and Verdolini, K. (2006). “Dominance and the Evolution of Sexual Dimorphism in Human Voice Pitch,” | |
Moreover, women in the fertile phase: Puts, D. A. (2005). “Mating Context and Menstrual Cycle Phase Affect Women’s Preferences for Male Voice Pitch,” | |
One hint as to why: Trivers, R. (1985). | |
Psychologist Susan Hughes: Hughes, S. M., Dispensa, F., and Gallup, G. G., Jr. (2004). “Ratings of Voice Attractiveness Predicts Sexual Behavior and Body Configuration,” | |
A second study, of the Hadza: Apicella, C. L., Feinberg, D. R., and Marlow, F. W. (2007). “Voice Pitch Predicts Reproductive Success in Male Hunter-Gatherers,” | |
One study had women view digitally masked: Grammer, K., Fink, B., et al. (2002). “Female Faces and Bodies: N-dimensional Feature Space and Attractiveness,” in G. Rhodes and L. A. Zebrowitz (eds.), | |
In a fascinating experiment, psychologist Meghan Provost: Provost, M. P., Troje, N. F., and Quinsey, V. L. (2008). “Short Term Mating Strategies and Attraction to Masculinity in Point-light Walkers,” | |
Evolutionary psychologist Karl Grammer: Grammer, K., Renninger, L., and Fischer, B. (2004). “Disco Clothing, Female Sexual Motivation, and Relationship Status: Is She Dressed to Impress?” | |
And studies from the Buss Evolutionary Psychology Lab: Buss, D. M. (1988). “The Evolution of Human Intrasexual Competition: Tactics of Mate Attraction,” | |
Indeed, studies have found: Comins, H., May, R. M., and Hamilton, W. D. (1980). “Evolutionarily Stable Dispersal Strategies,” | |
“Some guys just seem”: Cloyd, J. W. (1976). “The Market-place Bar: The Interrelation Between Sex, Situation, and Strategies in the Pairing Ritual | |
Men scoring high on self-confidence: Twenge, J. M. (2002). “Self-Esteem and Socioeconomic Status: A Meta-Analytic Review,” | |
Another study, for example, discovered that only men: Kiesler, S. B., and Baral, R. L. (1970). “The Search for a Romantic Partner: The Effects of Self-Esteem and Physical Attractiveness on Romantic Behavior,” in K. H. Gergen and D. Marlow (eds.), | |
The Buss Lab found: Hill, S. E., and Buss, D. M. (in prep.). “The Multiple Determinants of Self-esteem.” Unpublished manuscript, Department of Psychology, University of Texas, Austin. | |
“Balance,” according to social psychologists: Hummert, M. L., Crockett, W. H., and Kemper, S. (1990). “Processing Mechanisms Underlying the Use of the Balance Schema,” | |
By pairing paced copulation with an almond scent: Coria-Avila, G. A., et al. (2005). “Olfactory Conditioned Partner Preference in the Female Rat,” |