The 40-Year-Old Virgin getting waxed. Screenshot The longer you wait to have sex, the less likely you are to actually do it.

Of people who don't have any sexual experience at age 18, 3% still didn't have any sexual experiences by age 24 to 32, a new study, published in the Archives of Sexual Behavior, found.

The study was the first of its kind to delve into the reasons why these people stay virgins into adulthood.

We traditionally think people "wait" to have sex later in life for religious reasons. Previous research has shown that's true. But other reasons lead to extended virginity, too. Sex might not interest many adult virgins, potentially identifying them as asexual. Or they just can't attract partners.

Analyzing sex

The study included 2,857 participants (1,302 females and 1,172 males) in a health survey starting in the 1994-1995 school year. Researchers chose participants from a larger sample based on who had initially reported no sexual experience by age 18 — mostly non-Hispanic whites with educated parents.

They asked surveyed respondents in four waves: 1994-1995 (junior high or high school), about a year later, in 2001 (18-26 years), and in 2008 (24-32 years old), according to study researcher Carolyn Halpern, a professor of maternal and child health at the University of North Carolina.

Prior analyses have conflated two important terms: "technical" or "vaginal" virgins and actual virgins. The former may have abstained from vaginal sex to avoid potential negative consequences, like pregnancy or disease. But "actual" virgins have never engaged in any kind of sex — vaginal, oral, or anal.

More than one in eight (about 12%) of the 18-year-olds who failed to initiate sexual activity remained virgins into their 20s. Researchers did find that about 1% of the people surveyed reported no sexual attraction to the either gender at all. The survey questions, however, never mentioned asexuality, and thus didn't provide an adequate relationship between sexual non-attraction and asexuality.

"Among those individuals who reported no sexual experience as adults, only half of both males and females reported never having experience a sexual attraction to either sex. These results were consistent with prior research indicating that asexuality and sexual inexperience are not one and the same," the researchers wrote.

In the survey, 50% of of sexually inexperienced 18-year-olds gained some experience between the ages of 19 and 21, researchers found. That doesn't mean they necessarily lost their virginity though, Halpern explained. Of the remaining virgins, only 5% gained sexual experience between 27 and 30 combined. Approximately 3% of participants in the survey reported never having sex at all.

Virginity factors

Many reasons cause people stay virgins, but the main factors "may have been [inability] to attract sexual partners or ... little interest in sexual involvement," the authors write.

In other words, they can't get any or don't want any.

Lower cognitive performance, obesity, lower alcohol use, lower parental educational levels, and lack of sexual attraction may have contributed to individuals' sexual inexperience, as well.

"With inability to attract partners, we're inferring that's an opportunity issue. We have the measurement of obesity and the measurement of sexual activity, and in most cases, obese respondents are more likely to be in the inexperienced category. We're hypothesizing it's a reflection," Halpern explained.

Late onset of puberty, however, only affected males. Non-Hispanic Asian males were also more likely to have sexual inexperience after age 18 than white male respondents.

"Across the board, Asian males tend to be among those who are less sexually active and have fewer partners. There are different sets of values, different motivations for the future and thoughts about how sexual experience may or may not affect achievements down the road," Halpern said.