Several studies have found abstinence-only programs to be ineffective, and found no measurable impact on increasing abstinence or delaying having sex among its participants. Instead, studies have found that abstinence-only programs have actually decreased adolescents' confidence in a condom's ability to prevent HIV and other sexually transmitted infections. Below is a sampling of the reports and their findings.
The University of Florida conducted research on sex education in 2005-2006. The study found that:
Meanwhile, most of the respondents believed that:
An April 2007 study conducted by Mathmatica Policy Research, Inc., found that abstinence-only programs had no effect on the sexual abstinence of youth. The study also showed that students who attended abstinence-only programs were no more likely to delay sexual activity or have fewer partners.
A national report, Emerging Answers 2007, was released on November 6, 2007 by Douglas Kirby, Ph.D., and the National Campaign to Prevent Teen Pregnancy.  The report showed that abstinence-only programs are ineffective and that comprehensive sex education programs, including information about both abstinence and contraception, are effective.
Recently, the U.S Centers for Disease Control and Protection (CDC) released data showing that sex education programs do work to help discourage many teens from becoming sexually active before age 15. Instead, many Florida teens are being short-changed by ineffective abstinence-only programs.
Johns Hopkins Study
A study released in December 2008 by the Johns Hopkins Bloomberg School of Public Health showed that teenagers who pledge to remain abstinent until marriage were just as likely to engage in sexual activity as those who do not make this pledge. Even more alarming, those who made "virginity pledges" were significantly less likely to use condoms and other forms of birth control.
  Emerging Answers 2007, p 15