The simplest way to capture the differences between men's and women's sex drives is to consider how you'd answer this test: create a sentence using the words "sex" and "love."

If you're a woman, odds are your sentence goes something like this: "When two people understand each other, trust each other and love each other, then the sex is the best." If you're a man, chances are your sentence more closely resembles this: "I love sex."

It's a stereotype, it's a cliché and, more often than not, it's true. "We like to think of men having the higher sex drive—it's not always true, but more often, it is," says Eva Ritvo, MD, vice chairman in the department of psychiatry and behavioral science at the Miller School of Medicine, University of Miami.

"Each person's sex drive is like an appetite: Some people spend their whole life in the kitchen and think about food all the time; some people can skip lunch," says Ritvo, who is also chair of the department of psychiatry and behavioral medicine at Mount Sinai Medical Center, Florida.

As a rule, men don't like to skip lunch. But that's only the beginning of the story.

Sex drive—the way men and women think about sex and engage in sex—is a slippery concept. Researchers have a hard time quantifying it: Is it how often we think about sex? How often we want sex? How often we become aroused or actually have sex? Sex drive is all that, and more.

"Sex drive, which scientists now call sexual desire, is one of the most difficult to define," says Patricia Koch, PhD, associate professor of biobehavioral health and women's studies at Pennsylvania State University and adjunct professor of human sexuality at Widener University. Sexual arousal is easily identifiable—for men, it shows up as an erection; in women, lubrication (and enlargement of the clitoris). "But desire is not just about arousal or frequency—how often you have sex can depend on so many other circumstances and opportunities: whether you have a partner or not, whether you like your partner," Koch says.

Some researchers have begun to question how we define sex drive—insisting we have only looked at it from a male model, so of course women come up short. The male sex drive model resembles a straight line: It is a "linear model of sexual response, where first they have desire, then arousal, then orgasm," Koch says. For women, sexual interest follows a more meandering model. "Their drive is for emotional bonding and caring—once they feel that, then they get aroused and interested," she says. "Women want and enjoy a lot more sex play than men want. It takes them longer to be stimulated through sex play than men." What's more pleasurable to women may be affectionate physical contact that may or may not end in orgasm, and this indirectness is not a sign of a lack of sex drive.

How couples can get their sex drives in sync

What do we know about men's sex drives versus women's?

Reviewed by Cynthia Dennison Haines, MD  
SOURCES: Lonnie Barbach, PhD, psychologist and sex therapist, University of California, San Francisco; author, For Yourself, For Each Other: Sharing Sexual Intimacy. Richard Driscoll, PhD, marriage therapist, Knoxville, Tenn.; author, Intimate Masquerades: A Survival Guide for Those Who Know Too Much. Patricia Koch, PhD, associate professor, biobehavioral health and women's studies, Pennsylvania State University; adjunct professor, human sexuality, Widener University. Edward Laumann, professor of sociology, University of Chicago; author, The Social Organization of Sexuality: Sexual Practices in the United States. Laumann, E. Archives of Sexual Behavior, April 2006; vol. 34: p. 145–161. Esther Perel, couples and family therapist, New York City; author, Mating in Captivity: Reconciling the Erotic and the Domestic. Eva Ritvo, MD, vice chairman, Department of Psychiatry and Behavioral Science, Miller School of Medicine, University of Miami, Florida.; chairman, Department of Psychiatry and Behavioral Medicine, Mount Sinai Medical Center, Florida; author, The Concise Guide to Marital and Family Therapy. Pepper Schwartz, PhD, professor of sociology, University of Washington; past president, Society for the Scientific Study of Sexuality. Tom Smith, author, American Sexual Behavior: Trends, Socio-Demographic Differences, and Risk Behavior, National Opinion Research Center, University of Chicago. WebMD Features: "When Men Aren't in 'The Mood'" and "Why Women Lose Interest in Sex."

Reviewed on February 14, 2007