Sex education in schools does not encourage young people to have sex, according to a report in tomorrow's British Medical Journal. London University medical researchers found that men and women whose main sex education came from school were more likely to use contraception and no more likely to have sex before the age of consent than those whose main information came from friends or the media. Exeter University researchers found teenagers were less likely to have sex after an innovative sex education programme which included assertiveness training and sessions on negotiating in relationships.