Finnish study suggests screen time may boost teenage cognitive skills

A Finnish longitudinal study challenges existing concerns by linking increased childhood screen use with improved cognitive processing in adolescence, highlighting the importance of activity quality and gender differences.

A Finnish study is adding an unexpected wrinkle to the debate over children’s screen use: more time spent on screens across childhood was linked with better cognitive processing in the teenage years. The finding does not overturn concerns about sleep, inactivity or overuse, but it does suggest that screen time may not be uniformly harmful and that the kind of activity matters as much as the amount.

Researchers at the University of Jyväskylä and colleagues followed children for about eight years through the PANIC study, a long-running project on physical activity and nutrition. Their analysis covered 260 teenagers, with an average age of 15.8, and compared reported screen use, exercise and sedentary behaviour with later performance on computer-based tests of learning, attention, memory and processing speed.

According to the researchers, one plausible explanation is that screens are not only entertainment devices but also tools for active mental work. Children may use them to solve problems, build skills, create content, communicate or play games that demand planning and fast decision-making. Petri Jalanko, a doctoral researcher at the University of Jyväskylä, said the key issue is the quality of screen use, not just the total time spent in front of a device.

The study also found that physical activity related differently to cognition in girls and boys. Girls who had done more light activity over childhood tended to show stronger working memory, while boys who had taken part in more organised exercise showed a similar advantage. Working memory is the mental system that helps people hold and use information briefly, such as when following instructions or doing sums in their head.

Not every result pointed in the expected direction. Teenagers who reported less unsupervised physical activity sometimes performed better on measures of cognitive processing, although the researchers did not take that as evidence that free play is unhelpful. They argued instead that these patterns may reflect the many different ingredients that shape a child’s day, including structure, supervision and the mental demands of an activity.

The study also highlights a common weakness in research on children’s habits: not all measures capture the same thing. Wearable sensors can record movement, but they cannot tell whether a teenager is studying, gaming, drawing or chatting online while sitting still. That helps explain why the device-based measures did not show the same clear links with cognition as the questionnaires did. The findings were published in Pediatric Exercise Science, and the authors said larger studies are needed before any firm conclusions can be drawn about cause and effect.