Young adults who take virginity pledges do not have a lower rate of sexually transmitted diseases than those who do not pledge, according to a recent study by sociology professors at Yale and Columbia.

Hannah Bruckner of Yale and Peter Bearman of Columbia analyzed data from a National Longitudinal Study of Adolescent Heath about the sexual histories of individuals between 18 and 24 years old. Pledgers in the study did have fewer sexual partners, lower levels of non-monogamous partners and first sex later than non-pledgers, Bruckner said.

“We found pledgers did not have lower STD rates than others, even though they scored lower on all of the risk factors,” she said.

Although they have sex later and with fewer people than non-pledgers, young adults who take virginity pledges do have premarital intercourse. According to an article by Bruckner and Bearman in the March 18 issue of Journal of Adolescent Health, 61 percent of pledgers had engaged in sexual intercourse by the time they were interviewed, while 90 percent of non-pledgers had had sex before this time. Of those with sexual experience, 88 percent of pledgers had premarital sex, as did 99 percent of non-pledgers.

While in the 12 months before they were interviewed, pledgers and non-pledgers were equally likely to use condoms, the pledgers were significantly less likely to use a condom during first sex, Bruckner said,

He said pledgers were also less likely than non-pledgers to be tested and treated for STDs.

“Most people don’t know that they have STDs,” she said. “Most STDs we study in our lab are asymptomatic.”

According to the article, non-pledging females were almost twice as likely to be tested for an STD as pledging females.

Bruckner said the STD rate of pledgers might be related to non-vaginal sexual contact.

“At that age, 18 to 24, there’s a small minority of young adults who don’t have intercourse per se, so you could call them technically virgins, but they do engage in oral and anal sex,” she said.

Among those surveyed who had not engaged in vaginal intercourse, pledgers were over six times more likely than non-pledgers to have engaged in oral sex, Bruckner and Bearman reported. Male pledgers who had not had vaginal intercourse were four times more likely to have had anal sex than their non-pledging counterparts, according to the report.

In an interview on NBC’s Today Show March 21, National Abstinence Clearinghouse President Leslee Unruh said it is “not fair” to blame abstinence pledges for teens having other forms of sex and called the study “junk science.”

“If you look at the references on the study, and I’ve read every single one of them, they’re enemies, outrageous enemies, of abstinence until marriage programs,” she said, noting that Congress is currently working on legislation to spend money on abstinence until marriage programs. “And this is all politically charged and this is all about follow the money.”

She said the Centers for Disease Control and the National Institutes of Health have both said there are less children having sex than those that are and have credited the abstinence until marriage movement.

Dr. James Perlotto, chief of student medicine at Yale University Health Services, said the results are fairly consistent with what he has seen in practice.

“In my experience [the STD rate] tends to be about the same between those who talk about virginity pledges and folks who don’t,” he said.

Perlotto said he believes the notion that virginity only means abstinence from vaginal intercourse may contribute to the STD rates in those who have taken virginity pledges.

“Many students will say to me, ‘I’ve had oral sex, but I consider myself still to be a virgin,'” he said. “We know that oral sex can transmit STDs.”

Perlotto said herpes and gonorrhea are frequently transmitted through oral sex, and he has treated at least one student who contracted HIV exclusively from oral sex.

Dr. J. Dennis Fortenberry, a professor at the Indiana University School of Medicine who published a response to research in the same issue of the Journal of Adolescent Medicine, said he thought the research was well-executed.

“They were very thorough,” he said. “The investigators worked well to explore alternative explanations of the data.”

Fortenberry said policy makers should learn from this study.

“I think the bottom line for this study is that the current policy of abstinence-only is insufficient for public policy,” he said.