People You’ve Slept With: Calculation Errors Explained

Nov 05, 2009 • Research •

How many people have you slept with?

A horrible question that never did anyone any good. (I understand concerns about a new partner’s sexual health, but that’s what tests are for. Trying to calculate the risk of sexual disease based on how many partners someone has had has to be the most flawed method I’ve ever heard of. It only takes one time, after all.)

Conventional wisdom on the matter was best illustrated by the movie American Pie. Men tend to increase the number of sexual partners and women tend to lower theirs. Research seems to support this.

Norman Brown, a psychologist at the University of Alberta, finds that American men report an average of 18 partners while women report 5–but he thinks it’s more than people lying. Psychology Today elaborates:

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.

How do you count your lovers?

  • http://buttontapper.com Laura Roberts

    Nice post. I’ve definitely been an enumerator, which may produce underestimates, but is definitely closer to reality than the rough approximation method. I’d also be interested in seeing differences in calculation based on the semantics of the question “how many people have you had sex with?” as many people define sex differently or selectively. Maybe you only count the sex if it was good, or if you loved the person, or if you came, or if it was done in a particular style–am I right ladies? We also selectively eliminate the truly terrible from our numbers when we’re too embarrassed to admit we slept with certain people, whereas guys are all about overinflation of numbers, particularly when boasting to their male friends.

  • http://twitter.com/RobertFischer Robert

    I’m an enumerator. But this isn’t a surprise since 1) my number is low relative to the ballpark and rate given in the article, and 2) I’m apparently a woman in the way I think about sex.

  • http://twitter.com/RobertFischer Robert

    Oh, and +1 for not asking. I thought people figured out that’s a stupid and problematic question back in high school…?

  • http://www.wetasphalt.com/ Jay

    I enumerate. But really, if you think about it you’ll get to the right number eventually. It’s funny because if you ask me right off the bat, I’m likely to give you one number, and then I’ll think about it some more, and the longer I think about it, the more the number goes up.

    The other thing is that often what one person counts as sex might not be counted by somebody else. Particularly in the age of cyber/phone/email/cam sex. We’re way past an era where “third base doesn’t count” is the limit on how to figure who you did and who you didn’t screw.

  • Anaiis

    That’s interesting, Jay. I don’t count cyber, cam, or phone sex as sex. I don’t count people with whom I have only had manual or oral sex, either, which is funny, because if you ask me outright whether oral sex is sex, I will say, “yes, duh.”

    Fortunately, this doesn’t pose too large a problem, as I can only think of two incidents where the situation did not escalate to full-on sex.

    Laura, do you count bad sex? I do–I’m pretty heteronormative in this definition. If a penis went into a vagina or anus, it’s sex. Do I count as sex the encounters I’ve had with women, then? What about situations where I sodomized a man? This is fascinating. It’s making me question my tally (the accuracy of which I have doubted for many years, as it is).

    I’d say there was a column in here somewhere but… not a chance.

  • http://www.wetasphalt.com/ Jay

    i don’t count cyber/phone/cam, but I do count oral only. I wonder if blowjobs count for guys but not the girls giving them? Of course my point is that you can draw some lines fairly arbitrarily in order to get your count wherever you want it. Think about those girls who only have anal as a way of staying “virgins.”

    • Anaiis

      I was just thinking about the anal-sex-only-means-I’m-a-virgin population. That’s so funny, Jay. I count anal but not oral as sex. I think this is a great topic for a poll.

  • Miller

    I always make notes after the event. I also use those to chart monthly and annual averages, which can be…really, really, depressing. Well, at university I used to get girls to sign a note with name and date and location. Trained historian— documents matter. I only count actual intromission as sex. Anything else (oral, phone, manual, making out) is just Fooling Around, not sex. And— “good” or not, it counts if there’s intromission. That criterion is how you measure yourself against other males for rank-hierarchy purposes…and against the girls you’re with.

    • Anaiis

      You’re very thorough, Dr. I found an application that I liked for handling this early last year called BedPost. They’re still in beta, but they really excelled as far as charts and graphs, which, for people like you and I, are vital visual components of the tally. You should check it out. I’ll try contacting them to do a write-up, too.

  • http://malackey.tumblr.com malackey

    I always say I’ve been with enough people to know what I like, and what I’m good at. Saves me the trouble of trying to come up with an exact number.

    • Anaiis

      Malackey, you’re so good at evading, darling!

  • Orchid

    I enumerate, but sometimes I have a broader definition of sex than other times, e.g. whether I include oral or not.

    • Anaiis

      Does it depend on who’s asking, Orchid? How willing have you been in your dating to give up that kind of information to a lover?