IMAGINARY NUMBERS

A curious story recently in the New York Times took a more serious look at what comedians have observed for years, but this time with science as the punch line. The observation in the story should raise questions about official reports that aren’t so funny.

Times reporter Gina Kolata pointed out that scientific studies regularly find that men are more promiscuous than women, a phenomenon sometimes explained as a genetic impulse in which men try to spread their DNA as far and wide as they can while female strategy is to nurture a few children to adulthood.

Accepted wisdom on this is backed by data, and David Gale, an emeritus professor of mathematics at the University of California at Berkeley, found in a recent report from the Centers for Disease Control and Prevention that in the reporting by men and women, broken into four categories based on their number of partners, there were between 40 percent and 75 percent more male than female partners. Now the joke: With approximately the same number of men and women around, who are these men having sex with? Clearly, the data describe an impossibility, which a federal official in Ms. Kolata’s story concedes.

There are several possible minor influences on the totals – are men more likely to have sex with women from other countries? – but the simplest explanation is the most likely: Men overestimate the number of partners they have had and women underestimate their number.

This is worth noting for two reasons: first, as Professor Gale notes, the data perpetuate “the stereotypes of promiscuous males and chaste females.” Second, disproving the data in this case was fairly simple – they didn’t make sense on their surface. But if governments will report unlikely figures where their shortcomings are obvious, what about when they are not so obvious?

Perhaps a survey of government surveys is in order -if you could trust its results.