For the first time, researchers say they have clear evidence that abstinence education works and it could change the conversation about young people and sex.
"I think this is a game-changing piece of evidence," says Sarah Brown of the National Campaign to Prevent Teen, Unplanned Pregnancy.
For the study, released Monday in Archives of Pediatrics and Adolescent Medicine, researchers followed sixth and seventh graders in separate groups. In one, the focus was abstinence; in the other, they taught contraception and safe sex.
Two years later, they talked to the kids again.
Scholars Call the Results 'Groundbreaking'
Half the students learning about safe sex were now having sex, while only a third in the group focused on abstinence were engaged in sex.
But there was something else at play here. Researchers say it was how the topic of abstinence was approached.
Bristol Palin recently went on national television and pledging that she would wait until marriage before having sex again.
"It's a realistic goal for myself," she said.
But in this study, the teachers didn't take it that far. They purposely stayed away from religion, morality and marriage. For example, they did not preach waiting for sex until marriage or disparage using condoms.
A Different Approach to an Age-Old Subject
Instead, the study took a less traditional approach, discussing the drawbacks to having sex early, such as unplanned pregnancy and sexually transmitted diseases. Teachers even made kids list the pros and cons of having sex themselves.
"We began by talking to children and trying to understand their motivations, reasons for engaging in the behaviors from their perspectives," says John Jemmott III, a psychologist at the University of Pennsylvania and the lead author of the study.
"[Researchers] simply said delay," Brown says. "Wait a bit. Sex is serious. It has risks. And we just recommend you wait until you're older."
Traditional abstinence-only education, which emphasizes morality and waiting until marriage, has long been criticized and has lost funding for what many say is a lack of effectiveness.
Not surprisingly, though, abstinence advocacy groups praised this study and said the Obama administration's movement away from abstinence-only education in schools was not the right choice.
Talking to Kids About Sex, Communication Is Key
For nearly a year, ABC News followed 15-year-old Mahogany Bryant, through her pregnancy.
We went back to visit her today at her Lousiville, Ky., school where she told us she had never had a conversation with a teacher or a parent about sex.
"We didn't have those kinds of talks," Braynt said.
Some advocates say with these new results from sex education away from the home, there could be even greater results if the education from within the home, from parents.
Talking about sex is even more powerful coming from a parent, says Monica Rodriguez of the Sexual Information and Education Council, an advocacy group that supports comprehensive sex education.
"It may seem like they're tuning us out and turning their iPods up, but they want to hear from us," she says. "They're absolutely listening.