Children taught about sexual abuse in school are better able to recognise signs of it and do more to protect themselves, researchers have found.
But these children may also become more anxious and fearful of strangers as a result of this education.
"The important issue is whether ina real-life situation a child could use this knowledge," said Karen Zwi of Sydney Children's Hospital in Australia.
Sexual abuse is defined broadly, from direct bodily contact to sexual behaviour in a child's presence.
One in 12 American children between the ages of 2 and 17 have been victims, says a 2005 study from the University of New Hampshire.
This figure has sharply declined over the past 30 years, but it is hard to tell how much school programmes have contributed to this, said Joan Duffell, director of partnership development for Seattle's Committee for Children.
School programmes included puppet shows, colouring books and role-playing to teach children about the difference between good and bad touching and where to turn if they recognise abuse.
Dr Zwi and colleagues analysed 15 studies from the United States and Canada, done over the past 21 years.
Pooling results from nine of these studies, the researchers found that prevention education armed children with significantly more knowledge than their untrained classmates.
They were also more likely to act on this knowledge.
One study found that students in the programme were less than half as likely to accompany a simulated abductor as peers who were not enrolled - 21.5 per cent of them went with the "abductor", compared to 47.6 per cent of the untrained children.
But the studies followed the children no longer than a year after the programmes ended. And there are other limitations that come with studying such a sensitive topic.
Youngsters who felt more anxiety after going through one of the programmes also became anxious about other prevention programmes, said Ms Duffell, who was not involved in the analysis.
"The same kids reported they were glad to go through the programme," she added.
It is still not clear how best to teach kids to protect themselves, and at what age, the researchers wrote.
