A new report from Ofsted tells headteachers they must act on the assumption that sexual harassment is happening in their schools.

The inspectorate undertook a review of 32 private schools, state schools and colleges, speaking to more than 900 pupils about the prevalence of sexual harassment in their lives, in the wake of accounts of serious peer-on-peer abuse among young people being posted on the Everyone’s Invited website.

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It found that nearly 9 in 10 girls reported that they or their peers were sent unwanted explicit pictures or videos they did not want to see “a lot” or “sometimes”, with nearly 50 per cent of boys reporting the same. And 92 per cent of girls and 74 per cent of boys said that sexist name-calling happened a lot or sometimes to them or their peers.

The review recommends that, where headteachers and college leaders “do not have specific information that indicates sexual harassment and online sexual abuse are problems for their children and young people, they should act on the assumption that they are”.

In its review, Ofsted calls on school and college leaders to develop a culture where all kinds of sexual harassment are recognised and addressed, including the use of sanctions when appropriate.

It also calls on the government to consider the findings of the review as it develops the Online Safety Bill, in order to strengthen online safeguarding controls for children and young people.

The review found that “many professionals tended to underestimate the scale of sexual harassment and online sexual abuse”, although designated safeguarding leads and leaders “assessed the extent of the problem more accurately than teachers”.

Ofsted chief inspector Amanda Spielman said: “This review shocked me. It’s alarming that many children and young people, particularly girls, feel they have to accept sexual harassment as part of growing up. Whether it’s happening at school or in their social life, they simply don’t feel it’s worth reporting.”

Asked why Ofsted had not recommended that schools conduct prevalence surveys on the issue, Ms Spielman added: “The point for schools is perhaps less about weighing the pig and more getting on and addressing the problem, and what people want to see is people actually getting into the culture-building, the education, without spending too much into climbing into precisely what proportion of young people are affected.

“We haven’t found a reluctance to admit [issues] in the context of the visits when people saw the wider picture, and there seems to be very widespread acceptance from the people we’ve aired this with so far. So if, on inspection, we started to find schools insisting that they couldn’t possibly have a problem, it might be a sensible way to go but I’m not sure that pushing for 21,000 surveys at this stage would necessarily be the very best direction of resource.”

Geoff Barton, general secretary of the Association of School and College Leaders (ASCL), said: “Nobody can fail to be shocked by the finding that children and young people don’t see any point in reporting sexual harassment because it is seen as a normal experience.”

He added: “It seems that a gulf has opened up between what children and young people experience in terms of everyday sexual harassment and abuse, and what adult understanding is of the scale and severity of this issue.

“It is a generational divide which goes beyond schools and colleges and points to a much wider societal problem.

“The reasons why sexual harassment has become such a widespread issue are complex but it seems obvious that more must be done with greater urgency to tackle the misuse of social media and the availability of online pornography.”