Malala Yousafzai was shot for going to school in Pakistan.

Women fear the return of the Taliban in Afghanistan, and the loss of their freedom. A female student was horribly raped and murdered in India. Islamic fundamentalists are imposing Sharia law on women in northern Mali. I could go on. I won't except to say that, by comparison, Britain is a paradise for girls.

But there is a serpent in paradise: it's the sexualisation of children. When I first heard about teenage girls dressing like hookers and eight-year-olds in make-up I thought it might be another example of inter-generational angst. Ever since the mini skirt was invented hasn't every generation of parents worried about creeping moral degeneracy? Was this another twitch of the same paranoia? Sadly not.

The NSPCC took a measured look into what is now called sexting – the exchange of sexual messages or images on mobile phones. The charity conducted a pilot study by speaking to young people and following their activities online. It makes troubling reading.

The research found widespread knowledge of sexting among 13 to 14-year-olds. They discovered that in theory, those who take part in sexting are volunteers – but not really. Young teenagers want to belong. They're drawn to the gossip, banter and flirtation of the cool group so they join in. But taking part has a price. Those who are "in" have to look right, perform and compete. They have to judge and be judged. So although it's voluntary, it's pressurised.

Girls are cajoled, flattered and persuaded to take part by boys. But once they do the age-old double standard raises its head. In this most modern of practices, it thrives. The NSPCC found considerable evidence of sexually active boys being admired and rated while sexually active girls were denigrated and despised as sluts.

Boys risk being ostracised by their mates if they don't brag. Girls risk being ostracised if they don't keep what they have done a secret. Plus ca change, plus c'est la meme chose. The pressures are multiplied by the fear any photographs or video of their actions can be posted in a moment around the world. It was just such a terror that preceded the death of 13-year-old Chevonea Kendall-Bryan last week. After claiming a boy had secretly filmed her while forcing her to perform a sex act, she texted: "How much can I handle? HONESTLY. I beg you to delete that." She fell to her death from a window ledge. What a tragic waste.

It doesn't just affect those who take part. There is a wider sexual pressure which many find oppressive. They're rated if they're thin, have large breasts (or, for boys, big muscles). There's pressure to watch porn, to be photographed naked and performing sex acts.

The charity says girls are most adversely affected. A few say they choose to behave this way but many more are harassed by the boys. And because the entire culture (for girls) is shrouded in secrecy and shame, parents and teachers fail to spot what is going on and don't give the support they need.

According to Jon Brown of the NSPCC, it has to be brought into the daylight. Open discussion is needed to undermine the culture of silence, he says. But it's a delicate operation. In each classroom there are likely to be abusers, victims and bystanders. Most disturbing of all, the teenagers told the charity the pressure starts in the final two years of primary school. It peaks at about 14, after which the young people develop strategies to bat it off, according to Mr Brown.

So just when parents think their children are on the threshold of being sexually aware, some are already veterans. If all of this was evidence of a new attitude to sex, of a more relaxed generation which treats it as a form of recreation, it would be shocking but not as disturbing. What's happening is insidious and damaging.

Sex is clearly as potent as ever – and as messy. There's evidence that children's bodies are maturing earlier but none to say they are emotionally any more mature than they ever were. And where previous generations had clear-cut moral rules to guide them, today's children seem lost.

Yet, in the transition between primary and secondary school, they are as fragile as butterflies emerging from a chrysalis. They're shy and self-conscious romantics and frequently at their gawkiest. Some of the world's most beautiful women were awkward colts with braces and spectacles as they entered their teens.

To be rejected as not looking right – or to be used and vilified – could cause deep emotional damage.

I'm not blaming boys. They're also too immature to understand the long-term effects of their fun. Clearly adult supervision has to re-enter the field.

In 2011 Mumsnet took a stand with its Let Girls Be Girls campaign. Amongst other things the website wanted an end to padded bras and high-heeled shoes for small children. It insisted porn be displayed in newsagents above children's eyeline. And it was effective. The high street fell into line.

Justine Roberts, Mumsnet CEO and co-founder, said: "As parents we're told – often by our own kids – we've just got to live with it, the world has changed. But we don't have to. Our campaign ... and the new retail code of conduct show the power ordinary people can wield when they speak out forcefully on forums like Mumsnet against the pornification of our culture."

Jon Brown says Government and industry need to do more. We need discussion and more vigilance from parents about internet controls, though with an increase in smartphone use this has limited effect.

What he sees as more important are better personal, social and health education classes across the country. They are patchy and piecemeal at the moment. Young people want more of them. They say classes need to address body image, sexual stereotyping and peer pressure. They need to expose the real aims of advertisers and address what music videos are saying. And the discussion must start in primary school, albeit in an age-appropriate way. Do any of us know what that is any more?

No wonder parents are at sea: wanting their child to be happy and popular yet desperate to protect them from harm. Let's hope the daylight of open discussion helps alleviate these pressures. Let's hope it returns our girls to full enjoyment of the extraordinarily fortunate future that is theirs for the taking in this socially liberal country of equal opportunity.