Do Men Have a Sexual Advantage in the Post-Viagra World?

"Will you still need me, will you still feed me, when I'm 64?" The Beatles' enduring question wafted through my speakers as I pored over what, at first glance, seemed to be troubling new data about women and sex from a major university.

Older men have great sex lives; older women, not so much. Those were the findings of the recent study from the University of Chicago -- at least if you learned about the study from the popular media. But the simple deduction that turned up in some headlines about the study read more like old stereotypes than scientific conclusions.

"Men have shorter life spans than women on average, but when it comes to sexual life expectancy, the guys have the advantage," read a blurb on the Fox News Web site. "Women tend to live longer than men, but men have longer—and better—sex lives in their later years, new research shows," the editors of Health.com declared. "Women may live longer, but it appears men are more likely to go out with a smile," wrote a reporter for the Montreal Gazette.

In fact, the gender differences appear striking. From the study summary:

"These gender differences increased with age and were greatest among the 75 to 85 year old group: 38.9% of men compared with 16.8% of women were sexually active, 70.8% versus 50.9% of those who were sexually active had a good quality sex life, and 41.2% versus 11.4% were interested in sex."

There you go! Women may have longer average life expectancy but men win in the number of years of active sex they can expect to have, both at age 30 and at age 55, as the study demonstrates. Who wins? Those who live longer or those who have more nookie?

If that sounds a bit childish for you, how about an evolutionary argument? The NPR blog offers us one when discussing the study:

It's a stereotype, the aging man still keenly interested in sex, the aging woman, not so much. Some University of Chicago researchers have added statistical support for the cliche, with data indicating that, yes, more men of a certain age do seem more excited by sex than women of the same age. The study doesn't get into why this should be. It does make you wonder why the difference. One possible theory is that as far as nature is concerned, sex is really about reproduction despite the moral, cultural overlay we humans place on it. If that's so, then men's longer interest in sex relative to women would make sense since it would somewhat track the differences in male and female fertility.

Yup. All those men between the ages of 75 and 85 were perfectly capable of siring children long before the introduction of Viagra and friends, and the quality and motility (spontaneous mobility) of sperm did not decrease with increasing age. In the essentialist world, at least.

If this theory strikes you as dubious as it does me, why don't we spend a few minutes looking at the questions asked by the researchers. We might as well begin by seeing what they mean by "sex."

The two sets of data the study employed (one from 1995-'96 and one from 2005-'06) define sex a little differently. One simply asks whether the respondent had "had sex with anyone"; the other specifies sex as "any mutually voluntary activity with another person that involves sexual contact, whether or not intercourse or orgasm occurs."

Masturbation is not sex under those definitions. You got to have a partner! Keep that in mind when interpreting the results the study found. For instance, when people were asked about their interest in sex it did not include their interest in sex just with themselves.

This matters when looking at the differences between older men and older women, because heterosexual women, on average, partner with men older than themselves. As the lead author of the study, Stacy Tessler Lindau, notes: "Women outlive their marriages and their relationships." Sex with a partner is tricky to arrange if you no longer have a partner or if your partner is older than you and in poor health. One survey found that among the 75-85 age group 72 percent of men but only 39 percent of women had a partner.