Few debates generate as much anxiety among parents as the question of screen time. Headlines warn that smartphones are "destroying a generation", while technology companies insist that their products connect and empower young people. The truth, as so often, is more complicated than either side admits.
Part of the problem is that "screen time" is a crude measure. An hour spent video-calling a grandparent, coding a game or researching a school project is not the same as an hour spent scrolling through an endless feed of short videos. Researchers increasingly argue that what young people do on screens matters more than how long they spend on them.
That said, quantity is not irrelevant. Several large studies have linked very heavy use – more than five or six hours a day of recreational screen time – to poorer sleep and lower wellbeing. Screens can displace other activities that support health: exercise, face-to-face friendship and, crucially, sleep. Light from devices and the stimulation of social media late at night can delay sleep for teenagers, whose body clocks already push them towards later bedtimes.
It is worth noting, however, that most of these studies show correlation, not causation. Teenagers who are already unhappy may turn to their phones more, rather than their phones making them unhappy. Untangling cause and effect is notoriously difficult.
What, then, should families do? Rather than fixating on a single number, experts suggest asking three questions. Is screen use getting in the way of sleep? Is it crowding out exercise and real-world relationships? And does the young person feel in control of it, or controlled by it? If the answers are reassuring, the exact number of minutes may matter less than we fear.
