Sex Ed: Can I Get Your Number?

Few conversations are more fraught than the one that ensues when your partner asks about your previous sexual partners. But when researchers ask about lifetime opposite-sex partners, men report a total number two to four times higher than do women—a mathematical impossibility. What accounts for the discrepancy?

Few conversations are more fraught than the one that ensues when your partner asks about your previous sexual partners. But when researchers ask about lifetime opposite-sex partners, men report a total number two to four times higher than do women—a mathematical impossibility. What accounts for the discrepancy?

The conventional wisdom has it that people are lying to protect—or enhance—their reputation. Men jack up their numbers to look like studs; women slash theirs to avoid being perceived as promiscuous. But then why do men and women give identical answers when asked about the past year?

"It's not simply a case of people lying," says Norman Brown, a psychologist at the University of Alberta who finds that American men report an average of 18 partners while women report 5. "It has to do with self-presentation, estimation, and memory."

Women are more likely to "just know," or to have a tally somewhere, a method psychologists call "notches on the bedpost." Women are also more likely to use enumeration ("Let's see, Dave, Tarik, that guy from the gym…"), which produces underestimates, since people forget instances.

Men are more likely to use rough approximation ("Jeez, I don't know, like maybe 50?") or rate-based estimates ("Let's see, one a month for the last five years…")—a method that produces overestimates.

But the gender discrepancy isn't just a matter of counting. The survey method also matters. Extremely sexually active women downgrade phone estimates compared to online. (Men don't.)

Another factor is undersampling prostitutes, who don't get included in surveys due to "lifestyle issues"—they're not in the phone book and they aren't often home during dinner hours.

Men who "accidentally" overhear a conversation espousing conservative norms ("I don't blame her for breaking up with you. Having girls on the side is so uncool!") report fewer partners than those who hear someone espousing permissive norms ("You're too young to be tied down. You should be seeing lots of people!"), says Terri Fisher, a psychologist at Ohio State University. Women who overhear such conversations are unaffected .

Men are also more likely to stretch their numbers when the researcher is female. But the joke's on them. According to research by Douglas Kenrick, a psychologist at Arizona State University, the more sexual partners a man has had, the less attractive he seems.

Blanket Statements

What's the average number of lifetime sexual partners of various groups?

Americans vs. Indians

10.7 • 3.0

poets vs. accountants

11 • 3

whites vs. blacks

7.7 • 8.3

High scores

Wilt Chamberlain claimed he'd had sex with 20,000 women. How do other celebrities' self-proclaimed numbers compare?

Charlie Sheen: 5,000

Gene Simmons: 4,600

Julio Iglesias: 3,000

Jack Nicholson: 2,000

Hugh Hefner: 1,000

Isaac Newton: 0