The right-wing ascendancy in Wisconsin has been well-covered—at least with regard to labor issues. But conservative state legislators have been busy with other things besides their controversial push to strip public employees of their collective bargaining rights: According to the Milwaukee Journal Sentinel, members of the state senate are working to undo a law requiring that sex education classes teach about contraception in favor of a law allowing schools to teach abstinence only. One proponent of the change told the paper that students would respond if the classes were done right: “Abstinence training works, but you have to train them.” What should state legislators make of that claim?

If their goal is to delay sexual activity, reduce disease, or prevent pregnancy, they might want to think twice. It may be true that abstinence prevents disease and unwanted pregnancy, but it’s also true that abstinence education doesn’t. Instead, according to articles such as this 2006 study in The Journal of Adolescent Health, it is “comprehensive” programs—those that include abstinence teaching along with information on birth control and STD prevention—that achieve the most success in reducing rates of pregnancy and disease. One analysis cited in the 2006 report demonstrated that “comprehensive sexuality education effectively promoted abstinence as well as other protective behaviors,” (my italics) and that of 28 such programs studied, “nine were able to delay initiation of sexual intercourse, 18 showed no impact, and one hastened initiation of sex.” And while there was less data available on abstinence-only programs, reviews nonetheless found “no scientific evidence that abstinence only programs demonstrate efficacy in delaying initiation of sexual intercourse.” A 2008 study in the same journal similarly found that “abstinence-only programs had no significant effect in delaying the initiation of sexual activity or in reducing the risk for teen pregnancy and STD.” Comprehensive programs, on the other hand, “were significantly associated with reduced risk of teen pregnancy, whether compared with no sex education or with abstinence-only sex education.” In other words, proponents of the new legislation can argue that comprehensive sex education is inappropriate, but they can’t say it’s ineffective—especially compared to the alternatives.