Yesterday's newspapers were bursting with statistics on the sexual habits of the British public. Women have far more sexual partners than they did 20 years ago, the headlines said, but most adults are having less sex. Infidelity is viewed more harshly than ever before, but attitudes towards experimentationMore young people now have sex with partners of both genders, and the variety of types of sex that people experience has also increased. have become more relaxed. Worryingly, however, one in ten women report that they have been coerced into sex.

All these discoveries spring from an ambitious study repeated once a decade by the medical journal The Lancet. It is a snapshot of a society in which attitudes are changing fast. And among these changes is a decline in the average age at which people first have sex.

Today, 29% of women and 31% of men have been sexually active before the age of 16. Yet in the eyes of law, this is wrong: 16 is the age of consent for both gay and straight relationships.

Now a government public health expert has claimed that the current law is outdated and wrong. A substantial minority of under-16s are now having sex, said John Ashton, yet NHS workers are sometimes wary of talking to them too openly about contraception and sexually transmitted infections. His solution? Lower the age of consent to 15.

Ashton's suggestion was met with a wave of condemnation from the media and politicians. And a representative of the children's charity NSPCC warned that a change in the law could endanger vulnerable young people: 'Predatory adults would be given legitimacy to focus their attentions on even younger teenagers and there is a real risk that society would be sending out the message that sex between 14 to 15-year-olds is also acceptable.'

Another study published this week added weight to these concerns. According to an official report by the Children's Commissioner, some children as young as 11 are routinely subjected to sexual abuse by their peers.

Professor Ashton is not flippant about the dangers of underage sex. But it is going on whether the government likes it or not, he says, and teenagers simply ignore the current law as an irrelevance: perhaps decreasing the age of consent to 15 would encourage people to take it seriously. Besides, international comparisonsThese can be useful, but need to be treated with caution. There could be a huge range of reasons why statistics differ from country to country: the law, the culture, how rich or well educated the population is. As statisticians always say, correlation doesn't imply causation. suggest that people in countries with lower ages of consent actually tend to start having sex later.

But many people worry that lowering the age of consent would send a dangerous signal. Even if some people don't obey the law, they say, it is vital that the statute books reflect the fact that childhood sex can be traumatic - especially in a culture where pornography and sexual imagery are so widespread. The government must not add to the already intense pressure that some young people feel under.