Virginity Among Unmarried Heterosexual 25-to-45-Year-Old Americans

I just saw a fascinating study on the subject,
Eisenberg et al., Who is the 40-Year-Old Virgin and Where Did He/She Come From? Data from the National Survey of Family Growth.

Unfortunately, the New Scientist blog post about the study erred in an important way: It reported that among men and women “aged 25 to 45,” “13.9 per cent of men and 8.9 per cent of women said they have never had sex.” But this is true only among the single men and women (the study explicitly mentioned this limitation, but the New Scientist item didn’t).

Furthermore, the study refers only to absence of heterosexual sex, and I take it that most homosexuals wouldn’t really be thought of as “virgins” juts because they hadn’t had heterosexual sex. Limiting the results to virginity among single non-homosexuals (i.e., people who say they are heterosexuals, bisexuals, or “something else”) age 25 to 45 would yield 11.1% virginity among men and 7.7% among women. And the study also appears to count only genital sex, and not, for instance, oral sex; I know there’s disagreement among people about whether someone who has had oral sex qualifies as a virgin. (See the description for the EVERSEX variable here; the definition is not as clear as to males.)

This having been said, the survey has some very interesting and statistically significant findings (all these are based on the multivariate regressions, which control for age, race, college degree, income, urban/rural residence, religion, weekly religious services attendance, alcohol consumption in the past year, marijuana in the past year, smoking in the past year, history of military service [men only], history of incarceration [men only], health status, body mass index, and sexual orientation):

1. There seem to be no statistically significant correlations between virginity and age, so the results aren’t substantially skewed by 25-year-olds who just haven’t had sex yet — and, to the extent they are (and some such skew is inevitable), that would be offset by something else, presumably greater incidence of virginity 20 years ago, when the 45-year-olds were 25.
2. Unsurprisingly, people who attend religious services weekly were considerably more likely to be virgins; the ratio was 5 for men, 4 for women.
3. The incidence of virginity among men was lower for people with a history of military service (6 times lower) and incarceration (8 times lower). Recall that we’re talking here about absence of heterosexual sex, so either coercive or opportunistic homosexual sex in prison isn’t covered.
4. The incidence of virginity was 4 times higher both for men and women who had not had alcohol in the past year, and that’s with a separate control for weekly religious attendance.
5. The incidence of virginity was 3.5 times lower for black women than for white women, and 3 times higher for Asian women than for white women. (The latter number is the only one I quote that isn’t statistically significant at the 95% level, but it is very close — it’s statistically significant at the 94% level.)
6. The incidence of virginity was over 5 times higher for women who had a college degree than for those who didn’t. And note that this is among single women, so the later marriage age among women with college degrees doesn’t seem to explain all of this.
7. Health status, body mass index, income, urban/rural residence, religion (as opposed to frequency of religious attendance), and marijuana use in the past year were not statistically significantly correlated to virginity.