Although the United States spends about $88m (£44m; €65m) a year teaching teenagers to abstain from sex outside marriage, young people in the programmes are just as likely to have sex as those who don't receive counselling, a new study says.

Teenagers who received abstinence education did not delay sexual activity any longer than those in a control group. When they became sexually active they had the same number of partners and were as likely to use condoms or other contraceptives as those who had not been counselled.

Sharon Camp, president and chief executive officer of the Guttmacher Institute, which studies reproductive issues, said, “This …