IStock Photo 8050494 © Nikolay Suslov

Despite the sexual revolution and the popularity of the pill, underage boys are not having lots more sex than they did at the mid-point of the 20th century. But for women, the numbers tell a very different story.

Of men born in the 1950s, 1 in 5.92 reports having had sex before his 15th birthday. Women of the same era claim to have led a much more chaste existence—only 1 in 15.63 reports being sexually active before they turned 15.

But in the 21st century, women are catching up to men. In surveys conducted in 1999-2002 by the CDC, the odds a man aged 20-29 reported losing his virginity before the age of 15 were 1 in 4.63. The odds a woman of the same age also reported having sex for the first time before her 15th birthday were 1 in 5.35. And despite the stereotype of teenage boys being more sexually adventuresome than their female peers, the percentage of males and females aged 15-19 who reported never having had sex was nearly identical in 2002: 54% of males and 53.2% of females (PDF).

When you are talking about the most intimate experiences of human beings, every data point contains a story. The teens were asked “how much first intercourse was wanted,” and the responses varied by both gender and age. Over 60% of all male respondents indicated they “really wanted it to happen at the time,” and among boys who had their first sexual experience at 14 years or younger, the percentage was 67.2% compared with 53.7% who had their first sexual experience at 18-19 years of age.

Girls indicated far more ambivalence, with 33.9% agreeing they had fully wanted their first sexual encounter. The younger the girl was when the encounter occurred, the less likely she was to have reported wanting it—only 18.2% of those having sex at age 14 or under compared to 51.9% of girls who first had sex at 18-19 years of age. Overall, 52.7% of female respondents reported having “mixed feelings” about their first sexual experience compared to 32.7% of males.

Surveys are interesting both for what they ask and who they ask—but just as interesting are the questions never posed. The CDC polled only females about their relationship status in regards to their sexual activity. They found that three-quarters of the women responding reported their first sexual experience was in the context of a “going steady” relationship—but girls who began having sex at 14 years or younger were far likelier than older teens to report their first partner was someone they had just met or a friend.

Sexual experience at an earlier age also often led to multiple partners. One quarter of girls and over 31% of boys who had their first sexual experience before their 15th birthday reported 7 or more sexual partners.

Interestingly, only girls were asked if their first sexual experience was voluntary, and overall nearly 10% reported that it was not. The younger the girl was at the time of the sexual encounter, the more likely it was to be involuntary, with 18% who were 14 or younger reporting the act took place against their will.

The trend toward having sex at a younger age appears to be continuing. A 2007 CDC survey found that of male high school seniors, 6.7% reporting having sex before the age of 13. When the same question was asked of freshmen the percentage went up to 13.5%.

There’s a significant gender gap here, but girls are following the same trajectory. Of females in their final year of high school, 2.4% report having sex before their 14th birthday. For freshman girls the percentage is 4.9%. For both genders, the rate reported among freshman is slightly more than double that of the senior class.