October 13, 2006

"Every 52 seconds": wrong by 23,736 percent?

Well, I wasn't going to blog this, because it's got nothing directly to do with speech and language. But it does have to do with rhetoric, and with the use of authoritative-sounding assertions backed up by empty references to scientific studies, a topic that we've been featuring recently. And several readers have asked me about it, based on my earlier posts about the "emerging science of sex differences". So here goes.

On page 91 of The Female Brain, Dr. Louann Brizendine writes (emphasis added):

Males have double the brain space and processing power devoted to sex as females. Just as women have an eight-lane superhighway for processing emotion while men have a small country road, men have O'Hare Airport as a hub of processing thoughts about sex whereas women have the airfield nearby that lands small and private planes. That probably explains why 85 percent of twenty- to thirty-year-old males think about sex every fifty-two seconds and women think about it once a day -- or up to three or four times on their most fertile days.

This striking different in rates of sexual thoughts is also one of the bullet points on the book's jacket blurb -- but there, female sex-thought frequency is downgraded from "once a day" to "once every couple of days":

  • Thoughts about sex enter a woman's brain once every couple of days but enter a man's brain about once every minute

Whatever the exact numbers, it's an impressive-sounding difference -- scientific validation for a widespread opinion about what men and women are like. And this is interesting stuff, right at the center of social and personal life, so you're probably wondering about the details of the studies that produced these estimates.

The end-notes for the quoted segment from p. 91 yield the following references:

1. Bancroft, J. (2005). "The endocrinology of sexual arousal." J Endocrinol 186(3): 411-27
2. Laumann, E. O., A. Paik, et al. (1999). "Sexual dysfunction in the United States: Prevalence and predictors." JAMA 281(6): 537-44.
3. Laumann, E. O., Nicolosi, et al. (2005). "Sexual problems among women and men aged 40-80: Prevalence and correlates identified in the Global Study of Sexual Attitudes and Behaviors." Int J Impot Res 17(1): 39-57.
4. Lunde, I., G.K. Larsen, et al. (1991). "Sexual desire, orgasm, and sexual fantasies: A study of 625 Danish women born in 1910, 1936 and 1958." J Sex Educ Ther, 17:62-70.

Well, if you've been reading my earlier posts on (the popular presentation of) the "emerging science of sex differences", you can guess how this is going to come out. But let's go to the archives anyhow:

1. The abstract for Bancroft (2005) begins:

The relevance of testosterone, oestradiol and certain peptides (oxytocin (OT), ß-endorphin and prolactin (PRL)) to sexual arousal in humans is reviewed. In addition to behavioural studies, evidence of distribution of gonadal steroid receptors in the brain and the limited evidence from brain imaging are also considered.

These two sentences are a good summary of the paper as a whole, which says nothing whatever about how often women or men think about sex.

2. The abstract for Laumann (1999):

Context While recent pharmacological advances have generated increased public interest and demand for clinical services regarding erectile dysfunction, epidemiologic data on sexual dysfunction are relatively scant for both women and men.
Objective To assess the prevalence and risk of experiencing sexual dysfunction across various social groups and examine the determinants and health consequences of these disorders.
Design Analysis of data from the National Health and Social Life Survey, a probability sample study of sexual behavior in a demographically representative, 1992 cohort of US adults.
Participants A national probability sample of 1749 women and 1410 men aged 18 to 59 years at the time of the survey.
Main Outcome Measures Risk of experiencing sexual dysfunction as well as negative concomitant outcomes.
Results Sexual dysfunction is more prevalent for women (43%) than men (31%) and is associated with various demographic characteristics, including age and educational attainment. Women of different racial groups demonstrate different patterns of sexual dysfunction. Differences among men are not as marked but generally consistent with women. Experience of sexual dysfunction is more likely among women and men with poor physical and emotional health. Moreover, sexual dysfunction is highly associated with negative experiences in sexual relationships and overall well-being.
Conclusions The results indicate that sexual dysfunction is an important public health concern, and emotional problems likely contribute to the experience of these problems.

There is nothing at all in this paper about how often women or men think about sex.

3. The abstract of Laumann (2005):

The Global Study of Sexual Attitudes and Behaviors (GSSAB) is an international survey of various aspects of sex and relationships among adults aged 40–80 y. An analysis of GSSAB data was performed to estimate the prevalence and correlates of sexual problems in 13 882 women and 13 618 men from 29 countries. The overall response rate was modest; however, the estimates of prevalence of sexual problems are comparable with published values. Several factors consistently elevated the likelihood of sexual problems. Age was an important correlate of lubrication difficulties among women and of several sexual problems, including a lack of interest in sex, the inability to reach orgasm, and erectile difficulties among men. We conclude that sexual difficulties are relatively common among mature adults throughout the world. Sexual problems tend to be more associated with physical health and aging among men than women.

Again, there is nothing at all in this paper about how often women or men think about sex.

4. I haven't been able to read Lunde (1991), because Penn's library doesn't have the Journal of Sex Education & Therapy before the year 2000. But here's the abstract from PsycInfo, which suggests that the article focused on the relevance of social factors (since women of different generations report rather different numbers).

Studied female sexuality in 3 generations. A standard interview schedule was used, consisting of 300 precoded questions about sexuality, social conditions, and health. At the time of interview the women in each generational group were 70, 40, and 22 yrs old. Of these women, 72%, 67%, and 95%, respectively, had experienced spontaneous sexual desire, and 88%, 96%, and 91% had experienced orgasm. Also, 38%, 47%, and 81%, respectively, had masturbated at least once, and fantasies during masturbation were used by 50%, 48%, and 68%. Seven percent of the women born in 1910 and 44% of women born in 1958 had sexual fantasies in general, and 14% and 39% had fantasies during intercourse.

It's not clear whether the frequency of these women's thoughts about sex was covered. In any case, the paper only deals with women, and so could not have included any relevant information about the frequency of men's sexual thoughts. This paper is discussed briefly in Andersen, Barbara L.; Cyranowski, Jill M. "Women's sexuality: Behaviors, responses, and individual differences." Journal of Consulting and Clinical Psychology. 63(6), Dec 1995, 891-906, which summarizes its relevant findings as follows:

Epidemiologic data indicate that women use sexual fantasies to increase sexual desire and facilitate orgasm (Lunde, Larsen, Fog, & Garde, 1991).

Andersen and Cyranowski do, as it happens, report some other research that actually measured the frequency of sexual thoughts among women and men -- with results totally at variance with Brizendine's assertions:

Data comparing the frequency of internally generated thoughts (fantasies) and externally prompted thoughts (sexual urges) among young heterosexual men and women indicate that men report a greater frequency of urges than do women (4.5/day vs. 2.0/day), although the frequency of fantasies were similar (2.5/day; Jones & Barlow, 1990).

That reference is Jones, J. C., & Barlow, D. H. (1990). "Self-reported frequency of sexual urges, fantasies, and masturbatory fantasies in heterosexual males and females." Archives of Sexual Behavior, 19, 269-279. (According to its PsycInfo abstract, this study involved "49 male and 47 female heterosexual undergraduates" -- probably one introductory psychology course -- who "self-monitored the frequency of fantasies, urges, and masturbatory fantasies for 7 consecutive days". And "urges" are "externally provoked sexual throughts", while "fantasies" are "internally generated sexual thoughts".)

Hmm. Adding up this study's tally of undergraduate male sexual thoughts, we get 4.5 male urges + 2.5 male fantasies per day on average, for a total of 7 sexual thoughts, or one every (24*60*60/7 =) 12,342 seconds. Compare Dr. Brizendine's figures: "85 percent of twenty- to thirty-year-old males think about sex every fifty-two seconds". That's more than 237 times hornier -- even if the other 15 percent never thought about sex at all, the average frequency would still be at least two orders of magnitude greater than Jones & Barlow report. (And they sampled male undergraduate psychology students, who must surely be near their life maximum of sexual consciousness.)

How about the female numbers? Jones and Barlow's student diaries yielded 2 female urges + 2.5 female fantasies per day on average, for a total of 4.5 sexual thoughts per day. That's 450% greater than the "once a day" that Brizendine cites in the book's text, and 900% greater than the "once every couple of days" rate in the jacket blurb. Not that the average self-reports from the "47 female undergraduates" in Jones and Barlow's 1990 American sample should be taken to stand for the nature of all women in all times and places -- but this is still 47 more women than we've been able to connect with Brizendine's estimates, at least so far.

Note also that the Jones and Barlow numbers for women amount to one sexual thought every (24*60*60/4.5 =) 19,200 seconds. But you're not going to sell any books by writing that "Men think about sex every 12,300 seconds, while women only have a sexual thought every 19,200 seconds".

OK, so where did Dr. Brizendine get her numbers? Not from the references that she cites, that's for sure. If you can find the source, please tell me.

While I'm waiting, I'll tentatively adopt the view that the 52-seconds part has something to do with these other statistics I found on the web:

Every 52 seconds, a marijuana smoker is arrested in America.
At high-volume sites, someone does a scan every four seconds and a search every 52 seconds, on average.
Once we got rolling, we were pushing an empty concrete truck out of here and back on the road every 52 seconds.
The site has become so popular that two million names are being added every month, with families being connected every 52 seconds.
Every 52 seconds during the school day, a Black high school student drops out.
Genes Connected has become so popular it is now connecting families every 52 seconds*² from a database of over 10 million names.
Ezzatollah Molainia, deputy director-general of State Prisons Organization, said yesterday: "The available statistics show that every 52 seconds, one person is taken to prison in Iran."
In continued testing, first-time users have proven to develop a unique idea every 52 seconds, and help solve a more significant "problem" within 30 minutes.
Diabetes, the body's failure to metabolize blood sugar properly, now strikes Americans at the rate of one new case every 52 seconds.
Unless sh*t blows up every 52 seconds, the audiance walks away with a "Worst. Movie. Ever." attitude.
Right now I'm in the second day of a bad cold, which has caused me to sneeze approximately every 52 seconds for 48 hours.
On the average, a home fire in the US breaks out once every 52 seconds.
Some of the moves they manage to pull off are incredible, and you have to realise that the 70 star one manages an average of a star every 52 seconds.
NARPAC's numerologist has developed some sympathy for the DC 911 operators who are apparently answering a call every 52 seconds, 24 hours a day, year round.
Seven years later the company was producing a lawnmower every 52 seconds.
Human Rights Watch estimates a man is raped every 52 seconds in the US.
There are three lines in Georgetown, so that means that they produce 3 brand new cars every 52 seconds, 18 hours a day!!!
The Seventh-day Adventist denomination is one of the fastest growing churches in the world, baptizing one new member on the average of every 52 seconds.
I'm already clearing out a spam from my inbox once every 52 seconds.
Every 52 seconds in the United States, someone has an acute ischemic stroke.

On the internet, we also find these alleged quotations involving the number 52:

I refuse to admit that I am more than fifty-two, even if that does make my sons illegitimate. (Nancy Astor)
The Eskimo has fifty-two names for snow because it is important to them; there ought to be as many for love. (Margaret Atwood)
When you get to fifty-two food becomes more important than sex. (Tom Lehrer)
For it was Saturday night, the best and bingiest glad-time of the week, one of the fifty-two holidays in the slow-turning Big Wheel of the year, a violent preamble to a prostrate Sabbath. (Alan Sillitoe)
Nothing's a gift, it's all on loan. Out of every hundred people, those who always know better: fifty-two. (Wislawa Szymborska)
I was asked to come to Chicago because Chicago is one of our fifty-two states. (Raquel Welch)

And where do all these people get the number 52? Well, 52 is the number of weeks in the year and the number of cards in the deck, as well as the fifty-two stages of bodhisattva practice. But in some cases, I'm guessing, people just kind of like how it sounds. For example, a paper by A K O Brady of the Judge Institute of Management at Cambridge University ("Profiling Corporate Imagery: a Sustainability Perspective") includes this sentence:

Last year Skoda sold one car every 52 seconds, enjoying total sales of just over 450000 units.

Um, one car every 52 seconds would be 365*24*60*60/52 = 606461.5 cars per year . The cited 450,000 units would actually be one car every 70 seconds. But this is a minor mistake, merely a deflation of 35%, small by the standards of the corporate accountants of our era, and nothing at all compared to Brizendine's 23,736% inflation of male sexual urges.

[My attempts at exact quantification are frivolous -- but this is a blog post, right? If you want a serious review of the literature on relevant issues, try Roy F. Baumeister et al. "Is There a Gender Difference in Strength of Sex Drive? Theoretical Views, Conceptual Distinctions, and a Review of Relevant Evidence", Personality and Social Psychology Review, 5(3) 242-273, 2001. They agree with Brizendine's general point that "the weight of evidence points strongly and unmistakably toward the conclusion that the male sex drive is stronger than the female", and that "there is increasing evidence for the role of hormones in determining human sexual behaviors and motivations". However, neither the "every 52 seconds" phrase nor anything implying it is mentioned anywhere in their 32-page article, although they describe a systematic search of the literature as of 2001, including "over 3,400 citations" from PsychInfo and "approximately 2,000 citations" from MEDLINE.

Another useful survey is Leitenberg, H., & Henning, K. (1995). "Sexual fantasy". Psychological Bulletin, 117, 469-496. One relevant paragraph:

In a different approach to assessing frequency of sexual fantasies in general, Cameron (1967) asked 103 male participants and 130 female participants to estimate what percentage of the time they thought about sex. Of those who responded with a specific number, 55% of the male participants and 42% of the female participants said greater than 10% of the time. In a related study, Cameron and Biber (1973) interviewed 4,420 individuals and asked them whether they had had a sexual thought in the past 5 min (“Did you think about sex or were your thoughts sexually colored even for a moment?”); some interviews were conducted in the morning, some in the afternoon, and some in the evening. In the age range 14 through 25, approximately 52% of the male participants said yes, in comparison with only 39% of the female participants. In the 26- to 55-year age bracket, the respective percentages were approximately 26% for men and 14% for women. When asked what had been the central focus of their thought in the past 5 min, the percentage who indicated that it was related to sex was much less (approximately 9% for male participants 14 through 55 years old and 5% for female participants across this same age range), but the same gender difference was apparent. In the recently released national survey of human sexuality, in which a true random probability sample of 3,432 men and women were interviewed, 54% of the men and 19% of the women said they thought about sex every day or several times a day (Laumann, Gagnon, Michael, & Michaels, 1994). It appears clear from these studies that men report thinking about sex more often than do women, which is certainly consistent with the general stereotype.

So the studies certainly support the stereotype -- but nowhere can I find the slightest hint of empirical support for the "men every 52 seconds vs. women once a day" claim. Again, if you can turn up a source, please let me know, so that I can correct any perhaps erroneous implication that Dr. Brizendine is making stuff up.]

[Ellen Caswell writes:

About 30 years ago I read a book that may or may not be the source of these numbers, but it wouldn't surprise me if it is. I don't remember enough to identify the book, though someone else may recognize it, but it left a vivid impression.

What I do remember:

The book was written by two women who were consultants. It was advice to women in the workplace; I *believe* it was about taking on leadership roles--I associate it with the 1970s rise in feminism. I remember liking the book.

The section in question essentially said that it's useless for women to expect men to refrain from thinking of them sexually. My memory of it goes something like this:

Someone asked the authors to find out how often men and women think about sex, so they asked a number of people. The men said things like "All the time," "Once a minute," "Every thirty seconds." The women said things like "Every two or three days," "I don't have to think about sex because I have a satisfying sex life," "A couple of times a day." (All quotes, obviously after 30 years or so, are inexact.)

I originally figured that the "every 52 seconds vs. once a day" meme probably came from the demi-monde of self-help books, relationship counseling, pop psychology and workplace consulting. But in the case of the "words per day" meme, simple search techniques turned up dozens of instances -- whereas I haven't been able to find plausible prior or variant examples of the sex-thoughts frequency meme on the web, other than the even more preposterous urban legend, discussed on snopes.com, that "On average, men think about sex every seven seconds." If you locate some variants of this claim in semi-serious contexts, let me know.]

[Update 1/19/2007 -- Dr. Paige Muellerleile writes:

It turns out that I do not have a source for the 52 seconds "statistic," but our medical library does have access to the Journal of Sex Education & Therapy back to 1991, so I looked up the Lunde et al. article and found that the researchers in that article did not measure frequency of thoughts about sex. They did ask about lifetime prevalence (had they *ever* had a sexual thought or a sexual fantasy) but did not ask about frequency of such thoughts in a way that could yield some sort of thought-per-day figure.

I'm sure this is all very old news and that you have moved away from Brizendine, but in the event that it is not or you haven't--you can rest assured that this article, like the other three, is not focused on the frequency of sexual thoughts.


Posted by Mark Liberman at October 13, 2006 08:02 AM