Risky behaviour in the form of unsafe sex increases the prevalence of unwanted pregnancies and sexually transmitted infections (STIs) among young people. It is true this concern is not limited to the sexual behaviour of teenagers: between 1995 and 1999 instances of gonorrhoea increased by 58 per cent, while cases of chlamydia rose by an astonishing 76 per cent. However, trends in reported instances of STIs indicate that the bulk of the...