Across the rich world, a problem emerges. Children are spending more time hunched over iPhones working on their personal brands and less time building mud huts in the woods with their friends. Social stakes have got higher: the right post, message, or photo can give you a huge blast of approval; one mis-step could make you an outcast.

Playful and elastic real-life interactions have been replaced by unforgiving virtual hierarchies, in which your position is precisely quantified, recorded and made to matter more.

Young minds are more vulnerable to pressure from peers – for teens, often, their world is their friends and a rift can be devastating. Bullies now follow children home in their pockets; teenagers are surrounded, online, with perfected versions of people their age. As childhood shifts online, parents and campaigners are starting to sound the alarm, and asking that something be done about it. But what, if anything, should that be?

This week the UK government gave it a shot; it is considering banning the sale of smartphones to under-16s. This came in response to significant public demand – a survey by thinktank More in Common found 64% of people would be in favour of such a ban; another survey of parents by Parentkind puts the figure at 58%. But the policy also has one rather obvious flaw, which is that under-16s tend not to buy their own smartphones. A sales ban might stop a few children getting hold of these devices – but what about everyone else? And should the government be “microparenting” in the first place?

The problem of children and smartphones is knotty and lacks proper solutions. The first hitch comes with the difficulty of proving what everyone suspects: that spending time glued to a screen, rather than with their friends, is bad for kids. This might be partly because both “smartphone influence” and “mental health issues” are wide and amorphous concepts. “Smartphone influence” might include the effects of smartphone addiction, social media apps, messaging and access to instant information, as well as the displacement of real world activity. “Mental health issues”, meanwhile, is an ever-broadening category, and rising awareness means that problems are more often reported these days.

Nevertheless, in the recently published The Anxious Generation, the psychologist Jonathan Haidt makes a compelling case for a link: he notes a sharp rise in adolescent mental health problems across the Anglosphere and in Nordic nations coincided with the advent of the smartphone. Other explanations, such as economic or social factors, cannot explain this trend, he says. Instead, all the evidence points to one thing: a “firehose of addictive content” has displaced in-person socialising, rewiring children’s minds in a vulnerable development window.

His critics have replied that this pattern is not repeated everywhere. In a review in Nature, the psychologist Candice Odgers cites an analysis of 72 countries which found “no consistent or measurable associations between wellbeing and the roll-out of social media globally”. Even so, we lack a full alternative explanation for the uptick in teen mental health problems in the countries Haidt concentrates on. And even Haidt’s critics agree that some action is needed to curb the influence of social media: Odgers writes that these platforms should be reformed to take younger users into account.

Whether you think governments should act, tends to depend on your ideological leanings. Those with a distaste for government interference may argue that we should wait for all the evidence to come in. Others reckon it is better to be safe than sorry: as long as it doesn’t harm anyone, we should do something right away.

But the next problem to solve is what that action should be. Merely educating parents and children is unlikely to work: addictive habits, from food to cigarettes, are rarely conquered in this way. Adult life now centres upon the smartphone, so it is increasingly hard to keep children in a phone-free bubble.

Kids use their phones to stay in touch with their parents and find their way around. Indeed, smartphones have ushered in a new era of childhood freedom, one where parents permit their kids to wander off all day, safe in the knowledge that they can get in touch at any time.

And those who argue parents should ultimately be in control of whether or not their children have smartphones are missing something, too: peer pressure. No one wants to make their child a social outcast, but for as long as smartphones are the norm, parents will face a choice between protecting them and allowing them to fit in with everyone else.

Age bans on social media, meanwhile, have so far been fairly ineffective. The minimum age on nearly every platform, including TikTok, Instagram, X, Snapchat, and Facebook, is 13, yet a study by Ofcom finds that nearly 80% of 12-year-olds already have social media accounts.

Tech giants do not seem susceptible to pressure from campaigners and worried parents either. WhatsApp, just last week, lowered its minimum age limit from 16 to 13, despite mounting concern that the platform gives young people access to dangerous content.

So what might work? One idea is to try to make age limits harder. by punishing social media companies that do not properly enforce them. Another is an idea that has been floating around government departments for the last five years and was most recently announced by education secretary Gillian Keegan: a phone ban in schools. Many schools already have such policies in place requiring pupils to keep phones in lockers, or merely out of sight, but government guidance helps keep it consistent.

However, even this doesn’t solve everything. After lessons have ended, on weekends and holidays, children can go straight back on their phones. What is for certain is that more thinking is needed on this social problem, one that is only likely to get bigger.

• Martha Gill is an Observer columnist