In the US many teenagers are growing up sexually confused by the conflicting messages of abstinence-only education programmes promoted by the religious right and the administration of President George W. Bush.
Recent studies, as late as May in the Journal of the American Medical Association, show such programmes have little impact on sexual behavior, fail to prevent pregnancies and don't reduce rates of sexually transmitted infections (STI).
An excerpt from one abstinence-only video entitled 'No Second Chance' warns: "What if I want to have sex before marriage? ... Well I guess you just have to be prepared to die. And you'll probably take with you your spouse and one or more of your children."
Typically, such messages use guilt and fear to 'motivate' youngsters into abstaining from sex until marriage, discourage condom use and pass on inaccurate information and biased language.
Material from 'Sex Respect', which calls itself the 'world's leading abstinence-education programme,' informs us: "If pre-marital sex came in a bottle, it would probably have to carry a Surgeon General's warning, something like the one on a package of cigarettes".
Many public health activists see abstinence education as the greatest challenge to the country's sexual health.
"These programmes are less oriented toward giving teenagers reliable information about sexuality than toward indoctrinating them with conservative Christian views about sex," says an article by Eric Alterman, a senior fellow at the think tank Centre for American Progress.
A six-year study by Mathematica Policy Research, released in 2007 by the Department of Health and Human Services, found no evidence that these programmes actually increased rates of sexual abstinence.
In fact, students had a similar number of sexual partners as those not in the programmes, and had initiated sex at the same average age.
More than six in 10 adolescents have sex by the time they leave high school, according to government data. Each year, about 750,000 become pregnant and about 25 percent contract an STI.
This April, Congress held the first-ever hearing on the content of abstinence-only-until-marriage programmes.
"The evidence leads to only one conclusion: abstinence-only programmes represent a failed policy," says Vania Leveille, legislative counsel at American Civil Liberties Union (ACLU).
"They are driven by ideology and politics, rather than by science or good public health policy, and our young people are suffering as a result. Most troubling, they represent a purposeful campaign to mislead, distort, stifle and censor, and are part of a disturbing trend to politicize science."
Yet the Bush administration has only increased funding for these programmes, with a budget of $191 million for fiscal 2009, demonstrating the impact of religion and morality in shaping policy about sexuality and reproductive health.
The US is the only developed country with formal policies appropriating funds to abstinence-only programmes, says the National Abortion and Reproductive Rights Action League.
Researchers in reproductive health, such as Carol Roye, say: "The scientific literature is very clear. Abstinence education is not effective. Many teens will have sex. And they start having sex without birth control and without condoms because in class they're told that condoms don't work. So they think, why bother?"
Teenagers initiate a range of sexual activities around the same time, so it's critical for them to receive evidence-based education about different protective behaviors. About 55 percent of 15-19-year-olds have engaged in heterosexual oral sex, 50 percent in vaginal sex and 11 percent have had anal sex, research from the non-profit Guttmacher Institute revealed in May.
There is little or no research into how teenagers view abstinence education and how it impacts their lives.
Public health experts have called for well-rounded sex-education programmes that discuss abstinence and accurate information about reproductive health. It's not enough to teach teenagers to "Just Say No", many of them say.