Insanity is often defined as doing the same thing over and over again, while expecting a different answer. Scientists, on the other hand, often have to run the same tests over again, expecting the same answer, just to be sure. In the latest example, research has confirmed that abstinence-only sex education continues to be a complete failure, doing little to slow its spread.

In 2006, Professor John Santelli of Columbia University led a review of research into abstinence-only-until-marriage (AOUM) sex education programs, frequently referred to as “abstinence-only”. These had been mandated by many states and had received additional funding from the Bush administration. However, Santelli found no evidence such programs met their goals of reducing or delaying sex outside marriage, let alone cutting STI rates or unwanted pregnancies.

Although President Obama initially cut funding, congress increased it again in 2012 through budget deals, so Santelli led an updated study, published in the Journal of Adolescent Health. "The weight of scientific evidence shows these programs do not help young people delay initiation of sexual intercourse. While abstinence is theoretically effective, in actual practice, intentions to abstain from sexual activity often fail," Santelli said in a statement. "These programs simply do not prepare young people to avoid unwanted pregnancies or sexually transmitted diseases."

Moreover, a congressional investigation found that most of the larger programs don't just push their moral judgements onto students, but contradict scientific research or contain straightforward factual errors.

This hasn’t stopped their growth. In 2002, 64 percent of schools in America taught HIV prevention, but in 2014 this was down to 41 percent. Nor was this a consequence of better treatments reducing the danger that HIV poses. In 1995, more than 80 percent of school students learned about birth control methods other than abstinence. By 2011-2013, this had fallen to 60 percent for girls and 55 percent for boys.

Since 1982, the United States government has spent more than $2 billion on abstinence-only sex education within the United States. Another $1.4 billion has been spent internationally, under the guise of aid for HIV prevention – an even more disastrous move in light of the lack of treatment options in the countries where the money was spent when the program fails. Meanwhile, two weeks ago, a program using evidence-based research to prevent unwanted teen pregnancies was defunded. 

State laws are also influential. As the study reports: “When sex education is taught, 37 [states] require abstinence to be taught, 26 require abstinence to be stressed, and 11 that abstinence only be covered. Nineteen states require teaching that sexual activity should only occur in marriage.”

Abstinence-only education is also usually hostile to non-heterosexual relationships, with the paper adding: “Eight states either require negative information on sexual orientation or do not allow information to be provided on sexual orientation.”

A position paper in the same edition from the Society for Adolescent Health and Medicine also noted that, besides failing to meet its goals, abstinence-only education is based on an unsupported assumption. “While proponents for AOUM programs suggest that sexual activity outside of marriage is likely to have harmful psychological and physical effects, we find no evidence that consensual sex between adolescents is psychologically harmful,” they argue.

Ironically, during the era of abstinence-only education, American teenagers are starting sex later and are less likely to get pregnant. However, this is not because of such programs. The reduction has been considerably faster among those given comprehensive sex education than those simply told to wait for marriage.