A new study of almost 1,000 high school students published in the journal Pediatrics concludes:
"Virginity pledgers and similar non-pledgers don't differ in the rates of vaginal, oral or anal sex or any other sexual behavior...pledgers are less likely than similar non-pledgers to use condoms and also less likely to use any form of birth control."
Even more disturbing, the study found that students didn't exactly see the pledge as binding:
"The study also found that, five years after taking a virginity pledge, more than 80 percent of pledgers denied ever making such a promise."
It goes on to say that religious teens tend to delay having sex, but it is unrelated to any pledges they may take. Prior studies that concluded the effectiveness of abstinence programs failed to take this into account, which led to an overconfidence in the value of the pledges. In other words, abstinence programs are self-selecting: they get teens who weren't going to have sex anyway to take the pledge, and then they give the pledge the credit. It is like the witch doctor who thinks it takes both arsenic and a magic spell to kill someone.