Why the age your child gets a smartphone matters more than we thought
A new study published in the esteemed medical journal Pediatrics has landed with a thud — and it should give every parent, educator and policymaker pause for thought.The study, titled 'Smartphone Ownership, Age of Smartphone acquisition and health outcomes in early adolescence' was conducted by researchers from multiple institutions. It used data from the adolescent brain cognitive development study a long term research project tracking child development in the US.
The findings are stark: Adolescents who owned a smartphone by around age 12 showed higher rates of depression, poorer sleep and increased obesity compared with peers who didn’t. Even more concerning, the earlier the phone arrived, the worse the outcomes. This isn’t about moral panic. It’s about developmental timing.
Early adolescence is not just a smaller version of adulthood. It is a “high-gain” period — supports and stresses both have amplified effects. Timing matters. What parents introduce (or delay) during this window can shape mental health trajectories for years to come. Think of it as a neurodevelopmental construction zone. Sleep architecture is changing. Emotional regulation is fragile. Identity, self-worth and peer comparison are under active construction. When parents introduce a powerful, always-on device at this stage, it turns out that they are not adding a neutral tool — they are reshaping the environment in which development occurs. And the risks compound.
Smartphones don’t just displace sleep; they fragment it. They don’t just connect peers; they intensify comparison. They don’t just entertain; they train attention away from boredom, reflection and recovery. We have spent years reassuring ourselves that “kids will adapt” — but here's the thing, it turns out that biology doesn’t negotiate. The adolescent brain develops on its own timetable, not Silicon Valley’s product cycle.
What this study adds to the conversation we have been having in Australia, is not shock value, but clarity. It strengthens a growing evidence base (that Big Tech are keen to dispute), suggesting that earlier exposure carries measurable health costs, at exactly the point when young people are least equipped to self-regulate. This doesn’t mean banning technology. It means sequencing it better.
Just as we don’t hand car keys to a 12-year-old because “they’ll need them eventually”, we shouldn’t pretend that earlier access to smartphones is harmless simply because it’s common. The real question is no longer “Can kids handle smartphones?” It’s “At what age does the cost outweigh the benefit?” And now we know.
My advice to parents contemplating buying their 12 year old a smartphone, is this: if you genuinely care about your child's mental health, sleep and physical wellbeing, you need to stop framing this as a lifestyle preference and start treating it as a public health issue. Delay is not deprivation. In many cases, it’s protection.
— Michael Carr-Gregg AO Child and Adolescent Psychologist