Netflix series Adolescence shows how toxic social media is, that’s why we must keep our children away from these platforms - David Behrens

We may close our eyes to it; convince ourselves the dangers are exaggerated and that ‘normal’ families are immune to them. I recognise this ostrich in myself.

But the extent to which phones and PCs have become portals to dens of unspeakable harm is a new and alien phenomenon. How can you begin to police a culture you don’t understand?

Adolescence, the Netflix series that has reset the national debate on online safety, does not try to answer this – but what it does do is show us how the most insidious kind of radicalism, one that cuts across race, class and sexuality, can make almost any family susceptible.

Breathtakingly shot in real time, this is the story of Jamie Miller, a 13-year-old boy arrested for the knife murder of a girl in his school. It is set in Yorkshire but it could have happened anywhere and to anyone.

It already has. Kyle Clifford, we now know, murdered his ex-partner, her sister and their mother because he had absorbed the violent misogyny of the ‘influencer’ and alleged human trafficker Andrew Tate.

Adolescence references the fabrication that Tate personifies but it contains no big, dramatic revelations. It understands that’s not how cultural appropriation works. Rather, it creeps up on you.

It took a genuine role model, the former England football manager Sir Gareth Southgate, to explain in detail what drove the fictitious central character to kill.

Young men deprived of mentorship and reluctant to express their emotions had turned online in search of direction and encountered a new kind of role model, he said in his Richard Dimbleby lecture.

“These are callous, manipulative and toxic influencers, whose sole drive is for their own gain. They willingly trick young men into believing that success is measured by money or dominance, never showing emotion, and that the world – including women – is against them,” was how Southgate put it.

The internet has made up a word for this – of course it has – and the word is manosphere, a poisonous bubble in which misogyny is presented as normal behaviour to vulnerable young men in search of validation, perhaps because interaction with real females eludes them. It is, though, just the tip of an iceberg.

Below it is an underworld in which any dogma, no matter how dangerous, can be instantly legitimised. Perhaps it’s our own fault social media has been weaponised in this way: humanity will eventually reduce everything to its level. But the companies who control it don’t even try to rein in its excesses; they glorify the propagation of hate in the wrongheaded belief that it’s being done in the name of free speech.

Worse still, they profit from its exploitation. Two weeks ago Facebook – a tool, let’s not forget, designed originally for male students to spy on their female cohorts – won a court ruling in the US to stop one of its former directors publicising her memoir about the institutional harms she saw perpetrated during her years with the company.

Among these were said to be the practice of targeting adverts for clothes and cosmetics at teenage girls with eating disorders.

This is the kind of repellent influencing that today’s parents are up against and whose effects they will inevitably blame on themselves in the event of an unhappy ending.

The final, heartbreaking scene in Adolescence, in which Jamie’s dad sobs for the son he has lost, is visceral: there but for the grace of God go any of us.

The Prime Minister was among those apparently moved by it but he and Lisa Nandy, his invisible culture secretary, must now translate this concern into action by following the example of other countries in raising the age of digital consent to at least 16 and requiring Britain’s internet providers to block access to platforms that can’t or won’t police their content. There will be an outcry, no doubt, from libertarians but we will learn to live without them and live better.

I will never know how many mistakes I made as a parent but I know what I got right and it was my advice the first time I saw social media. I commend it to anyone. “This is toxic. Stay away from it.”