IMAGE: MATT CARDY/GETTY IMAGES
A TWELEVE-YEAR-OLD with a smartphone is now commonplace. A sixteen-year-old without one is a rarity. The gap between these two ages is the focus of unsettling new research. A long-term study published on December 1st of over 10,000 American children has found that those who received a smartphone before the age of twelve showed a higher likelihood of depression, sleep problems and weight gain compared with those who did not. The point is that timing matters.
By tracking children over time, researchers could compare those who got phones early with those who received them later. The results show a troubling gradient. The earlier the phone arrived, the stronger the associated risks. Even more tellingly, among children who were phone-free at twelve, those who acquired one by thirteen showed worse sleep and mental-health indicators a year later than those who remained without. The findings suggest the device is part of what drives those outcomes.
How that happens is not hard to see. Introducing a powerful, always-on portal to social media and the internet can disrupt foundational habits. Time spent scrolling replaces time spent exercising or engaging in face-to-face interaction. Perhaps most significantly, screens and sleep are fierce enemies. Many children keep devices in their bedrooms, where notifications shatter rest. Poor sleep, in turn, is a known catalyst for mood disorders as well as physical health issues.
It would be an error, however, to view this as a deterministic verdict. Not every child with an early phone will struggle. The research points to heightened population-level risks and not individual fate. The difference between a twelve-year-old and a sixteen-year-old is crucial: the latter has greater cognitive maturity and self-regulation. This is not an argument for never giving a child a phone, but for delaying the moment until they are better equipped to handle it.
The most practical advice for parents therefore is also the simplest. If a phone must be given, keep it out of the bedroom at night. This single rule mitigates the most destructive pathway from device to poor health. Parents who have already provided phones need not feel guilt, but may wish to reassess boundaries. The goal is harm reduction.
In the rush to connect children to the digital world, it is worth ensuring they are first firmly anchored in the physical one. ■
