Anyway, that’s what Robert Rector of the Heritage Institute says. OK, he doesn’t actually say that, but that’s what he implies. His nonsensical interpretation of a recent study of teens and virginity pledges is just one instance of a general failure to understand what the study really says.
The Journal of Adolescent Health published a study by Hannah Brückner and Peter Bearman in which they found that taking virginity pledges doesn’t reduce teens’ STD rates. Teens that took virginity pledges had fewer sex partners and started having premarital sex later, but they were less consistent with condom use and less likely to seek testing or treatment for STDs, so it was a wash.
It takes real work to understand what a study’s statistics mean, so errors are easy to make. Ceci Connolly of The Washington Post said that teens who’d taken virginity pledges were “more likely to experiment with oral and anal sex.” The study says that this is false. What the study does say is that pledgers are more likely than nonpledgers to engage in oral and anal sex while still maintaining their technical virginity by abstaining from vaginal sex. Nonpledgers were more likely to engage in oral, anal, and vaginal sex. Is this a case of the liberal media distorting the facts to make conservatives look bad? Don’t infer malice where ignorance is sufficient.
For his part, Robert Rector says that virginity pledges led to reduced levels of STD infection. The study features a statistic that could lead the unwary to such an unfounded conclusion. It says that nonpledgers had a 6.9% rate of STDs, inconsistent pledgers had a rate of 6.4%, and consistent pledgers had a rate of 4.6%. These differences, however, don’t result from different outcomes but from the different demographic makeup of the three groups. Black teens showed STD rates of about 8 times that of whites. Among white teens, pledgers and nonpledgers had about the same STD rates. The same is true among black teens. The reason that pledgers overall saw lower STD rates than nonpledgers is that there was a higher proportion of blacks in the nonpledger category. For Rector to claim that virginity pledges are what made the difference in STD rates (6.9% for nonpledgers and 4.6% for pledgers) is to imply that the virginity pledges turned black teens white, and that change in turn led to reduced STD rates. Is this a case of conservative think-tankers twisting the truth to make conservatives look good? It’s the old malice/ignorance wager again.
If all this confusion isn’t enough, there’s a more fundamental issue with the interpretation of the study. The study charts correlation but not causation. Since pledgers are self-selected, you can’t tell whether any results that the study reports are the results of the pledges or merely correlates of the pledges. For example, pledgers start having premarital sex later than nonpledgers. How much of that is due to the pledge, and how much is due to whatever factors led those teens to take the pledge? Maybe religious teens are more likely to take the pledge but also more likely to delay fornication, regardless of whether they actually take a pledge. This study doesn’t tell us what effect a pledge actually has.
Despite the confusion and its silence on causation, the study still does have something to say. It tells us what the pledge doesn’t do. It doesn’t reduce the rate of STD infection, and it doesn’t stop young people from having sex before marriage. Eighty-eight percent of pledgers wound up having sex before marriage anyway. Yet Bush is an ardent supporter of abstinence-only education in public schools. The problem with abstinence-only education is that it’s two steps divorced from reality. Taking an abstinence-ony class doesn’t mean that a teen will adopt abstinence as a birth-control policy, and (as this study shows) adopting abstinence as a birth-control policy doesn’t even make it likely that the teen will abstain.