Everything you’ve read about the ill-effects of screen time might be based on bad data

Ruh-roh. You know those warnings about the adverse effects of screen time we’ve been hearing for the last two decades? It turns out, the research might be flawed.

To be clear, screen time may well still be horrible for you. Or not. We don’t know.

The glitch is in the data: The vast majority of studies on media use depend on participants’ self-reporting their screen time. The intentions here are good: Researchers want to study people’s normal day-to-day screen habits, rather than carefully dolled-out screen minutes in a lab. Efforts to log usage are complicated by the fact that just because a screen is on does not mean someone is using it.

Now researchers on three continents collaborated for a new meta-analysis in Nature Human Behaviour, revisiting 12,000 studies. They found 47 studies in which 50,000 people had their screen time logged or tracked in addition to self-reporting it. The results: Just 5% of the self reports were accurate.

That’s bad. As the authors put it, “Self-reported media use correlates only moderately with logged measurements.” That’s like someone telling you that she slept four hours last night, and you later learning that she may have slept three hours, or six hours, or seven hours. Multiply that by 50,000 people. You see the conundrum.

Screen-time studies have connected media use with a host of negative outcomes, such as increases in depression, ADHD, and violence. “These highly flawed studies are over-inflating the relationships between digital media use and typically negative outcomes, such as mental health symptoms and cognitive impairments, which of course explains the pervading view that smartphones among other technologies are bad for us,” says coauthor Brit Davidson, a lecturer in management at the University of Bath’s School of Management.

The solution is not to exonerate screen time, but to better understand and track how people use screens. In the meantime, some guidelines may need a second look. “These questionable studies are also being used to influence policy,” says Davidson. “The UK and Canada both have forms of screen time guidelines based on poorly conducted research, which is clearly worrying and hard to reverse.”