Banning Phones: How Much Evidence Do We Need?
Evidence shows early access to smartphones is strongly associated with poorer mental health and wellbeing. But a lot of the evidence is correlational. What does that mean for schools and parents?
“But then why,” said Candide, “was the world formed?” “To drive us mad,” said Martin.
What's the effect of giving kids smartphones before 13? Not Good. A new global study, covering data from more than 100,000 young adults, reports that those who first received a smartphone before the age of 13 show markedly poorer mental health outcomes in their late teens and early twenties. The most striking associations are with increased rates of suicidal ideation and diminished emotional regulation. The authors claim these findings hold across a wide range of countries and cultures. Strikingly, they are not an artefact of one region or demographic.
What is driving these effects? The study highlights several mediating factors: early and unsupervised exposure to social media platforms, greater vulnerability to cyberbullying, chronically disrupted sleep patterns, and a weakening of family relationships through reduced direct interaction. These factors, taken together, create a developmental environment that undermines resilience and mental health at a crucial stage. This new study is typical of many but is the evidence causal?
Importantly, the study does not claim definitive causation. In the language of research, the evidence is correlational, not causal. In other words, we cannot yet say that handing a ten‑year‑old a smartphone will cause poor mental health. But we can say that, on a population level, early smartphone ownership is consistently linked to poorer outcomes. The question is how strong is that link? And should we be recommending sweeping policy based on a link?
This distinction matters, and sceptics often use it to argue against policy action. However, to my mind, the authors of the study make an unusual and powerful argument: even in the absence of causal proof, the sheer scale of the associations, combined with the plausible mechanisms of harm, justify immediate precautionary steps.
This kind of thinking is not new. Seat‑belt laws were introduced well before randomised trials could prove beyond all doubt that they save lives. Lead was removed from petrol not because of a single definitive study, but because of converging evidence from toxicology, public health, and developmental psychology showing serious risks.
Beyond Correlation: Multiple Lines of Converging Evidence
Researchers are right to be cautious about correlational data but as Jean M. Twenge has pointed out, there is compelling, converging evidence from multiple data sources pointing in the same direction. Her analysis of Monitoring the Future data shows that between 2012 and 2019 (when smartphones and social media moved from optional to almost universal among teens) depression among girls rose by 74% (13 percentage points) and among boys by 56% (8 points).
The spike during the pandemic years was significant but smaller, and by 2023 those pandemic‑related increases had receded, yet depression rates remained far higher than in 2012. In other words, even as the immediate shock of COVID‑19 faded, the long‑term upward trend in teen depression tied to a screen‑based social life continued. This pattern, where the rise predates and outstrips pandemic effects, adds weight to the argument that technology and social media use are not just correlated with but are plausibly driving much of the current mental health crisis among adolescents.
Furthermore, as Jonathan Haidt has pointed out, there is compelling, converging evidence that goes well beyond simple correlation. Longitudinal studies now show that heavier social media use predicts later increases in depression and anxiety, not just the other way around. Randomised experiments find that reducing social media use leads to measurable improvements in mood, and natural experiments (such as the roll‑out of Facebook or high‑speed internet) show community‑wide rises in mental health problems once access expands, particularly among girls. Combined with clear dose–response patterns and effect sizes comparable to established public‑health risks, these findings make it increasingly difficult to dismiss social media’s role as anything less than a significant causal factor in the current adolescent mental‑health crisis.
Perhaps most compelling are the "quasi-experiments" that examine what happened when social media arrived in different communities at different times. Braghieri, Levy, & Makarin (2022) studied Facebook's original rollout to specific colleges and found that "the roll-out of Facebook at a college increased symptoms of poor mental health, especially depression." Studies of high-speed internet rollout show similar patterns: in Spain, Arenas-Arroyo et al. (2022) found "a positive and significant impact on girls but not on boys" when high-speed internet arrived, with effects on sleep, homework time, and family relationships. In British Columbia, Guo found that high-speed wireless internet "significantly increased teen girls' mental health diagnoses (by 90% ) relative to teen boys."
What We're Really Debating: It’s Not The Phones
It is worth underlining what this debate is really about. It is not about banning all phones or denying children any access to technology. A phone can be useful. For ecample, texting a parent after school, using a maths app, looking up a bus timetable. The issue is not the hardware. The issue is the gateway it opens into billion dollar, algorithmically‑curated, AI‑driven social media environments long before a child’s sense of self, identity, and emotional stability are formed.
Platforms such as TikTok, Instagram, and Snapchat are not neutral spaces. They are engineered to maximise engagement through what James Williams calls adversarial design: systems that exploit cognitive vulnerabilities rather than serve human intentions. These platforms thrive by feeding users content that provokes strong emotions such as outrage, shame, envy, and fascination because these emotions keep us scrolling. Even adults, with decades of life experience, struggle to resist these hooks. For children, the effects can be far more destabilising.
Consider what this means for a ten‑year‑old who is still developing the neurological foundations of self‑control. Sleep is easily disrupted by late‑night scrolling; social comparison begins to warp self‑esteem; algorithmic feeds expose them to communities and content far beyond their emotional maturity. A 2023 report by the US Surgeon General highlighted the links between heavy social media use and increased anxiety and depression among adolescents.
The risk is not simply “screen time” in the abstract. It is early, unmediated exposure to an ecosystem optimised for manipulation rather than development. This delineation is important. When policymakers talk about restricting phones in schools, critics often assume this means denying access to all digital tools. But the conversation we need to have is more precise: it is about how and when children enter social media spaces designed to shape their attention, behaviour, and beliefs.
Digital Literacy: Swimming Lessons in a Riptide
Some argue that teaching “digital literacy” is key to helping kids make healthy choices but I think this is hopelessly naive. The construct of digital literacy presupposes a level of self‑awareness and judgement that younger children simply do not yet possess. Giving a ten‑year‑old unfiltered access to algorithmic feeds is like handing them the keys to a car and trusting that a few lessons on road safety will suffice. A 12 year old may intellectually understand that "not everything online is true" whilst simultaneously being emotionally overwhelmed by content designed to exploit precisely the psychological vulnerabilities that characterise their developmental stage.
Consider the sophistication required to resist algorithmic manipulation: recognising when content is designed to provoke anger rather than inform, understanding how recommendation systems work to keep users engaged, identifying the difference between authentic peer interaction and platform-mediated performance. These require not just knowledge, but emotional regulation, impulse control, and the ability to step back from immediate gratification. Precisely the capacities that are underdeveloped in younger children.
Think about the pull of sugar on kids. They know that eating gummy bears will lead to cavities, they know that chocolate is not the same as broccoli. But knowledge doesn't override biology. A child's developing brain is wired to seek immediate rewards with the consequences being suppressed like ? This is why we don't simply educate children about nutrition and then stock the kitchen with cupcakes, trusting them to make sensible choices.
Giving a 10 year old a smartphone and expecting them to use “digital literacy skills” to use it responsibly, is like taking them to McDonalds and expecting them to choose the salad.
The Care of Constraints
None of this means we should panic or succumb to moral hysteria. But it does mean we need to be clear‑eyed. The argument here is not for Luddite resistance to technology but for measured, developmentally informed caution. As with lead in petrol or seat belts in cars, we do not need perfect evidence before acting in the best interests of children. We need to look at the patterns, understand the mechanisms, and err on the side of protection. As the father of three girls aged 7 and under, I am concerned about what kind of digital world they will inherit and whether we are doing enough to protect their developing minds from premature exposure to systems designed to exploit them.
The broader question we must face is what kind of digital childhood we want to create. If we know that certain platforms are built to hijack attention and amplify harm, then shielding younger children from those platforms until they have the emotional and cognitive tools to navigate them is not a matter of nostalgia or technophobia. It is a matter of care.
One feature of human cognition is that when faced with an overwhelming array of options, people often become anxious, regretful, and less satisfied with whatever they ultimately choose. For children, whose capacity for decision-making is still forming, this burden is even heavier. When we hand a ten-year-old a smartphone with access to infinite content streams, we are not liberating them; we are subjecting them to thousands of micro-decisions every day about what to watch, whom to follow, how to respond, and whether to keep scrolling.
Pococuranté's Paradox: The Pleasure of No Pleasure
In Voltaire’s Candide, there is a moment when Candide and Martin visit the wealthy Venetian nobleman Pococuranté. Pococuranté owns great art, rare books, and lavish gardens, yet takes no joy in any of it. Candide, ever the optimist, imagines that such indifference might be a form of contentment, being above worldly pleasures. But Martin, the pessimist, cuts in with his bleak observation: “there is a pleasure in having no pleasure.”
Pococuranté’s lack of delight is not wisdom but weariness. He finds no happiness because he cannot truly value anything. Martin suggests that there is a strange satisfaction in his discontent, a kind of grim comfort in recognising the flaws of the world rather than trying to find joy within it. This tension between the naïve belief that more choice and more access bring happiness, and the deeper truth that too much can drain meaning says so much about our own digital age. Sometimes limits, not abundance, allow us to appreciate what matters. It’s in this spirit that we might understand the care of constraints, such as banning smartphones in certain settings, not as a denial of freedom but as a gift that preserves attention, relationships, and wellbeing.
I want my daughters to inhabit their own lives more fully, to experience unmediated moments without the relentless pull of notifications. I want them to know the pleasure of getting lost in a book without the anxiety of missing out on something happening elsewhere. I want them to have conversations that meander and deepen, not ones interrupted by the phantom buzz of a device. I want them to sit with discomfort long enough to learn how to process it, rather than reflexively reaching for a screen to escape whatever they're feeling.
I want them to develop friendships that exist in three dimensions, not just online. I want them to fail at things and recover, to be bored and discover what emerges from that emptiness, to have secrets and private thoughts that aren't immediately shared with an audience. I want them to know who they are before algorithms start telling them who they should be. Above all, I want them to be in life, and of life.
So many parents have kids on screen to try on lipstick at a store, to buy clothes, to shop, to have a break themselves… we haven’t even begun calculating the damage.
Thank you for this. I am going to go back and re-read Candide!
This is great. My wondering is if there is research being conducted on the smaller population of kids who are not users of social media nor are they addicted to tech. In the case of my two daughters, their approach to tech and social media is very different. One is very active and up to date on memes and trends-- buying the advertised gear, etc. , and she's very anxious. My youngest browses, but could care less-- she's a violinist, very active at college, volunteering at hospitals, and she has a clear vision for what she wants to do in the future.
My wife and I compare the different way they were raised. The oldest grew up in a house that was financially fragile, we worked several jobs, but we did enough for swim lessons, dance, art lessons, etc. However, we never encouraged her to stick anything out, defaulting to what many parents do-- exploring activities to find something she likes. For instance, when Tae Kwon Doe became boring-- she quit-- and we supported it so long as she finished the month we paid for.
The youngest one grew up with more financial security, she attended elementary schools I worked or led at at, however, we did not bob around trying to find what she liked for hobbies. We made the decision that she would play violin and encouraged her towards longer term goals, strong habits , and good taste in reading. She's actually grateful for it.
My hunch is that kids who are not reliant on social media and tech have learned the pleasure of delayed gratification and discipline, have long term goals and vision, and engage in enough analog activities and communities to bring meaning to their lives.
I'm a supporter of banning phones in schools and did so when managing high schools, but the big question is what replacement habits and behaviors must be taught to take the place of tech and social media?
Sorry for the long winded response-- but this got me thinking.