Does another hour on a tablet automatically mean a child’s thinking skills are slipping? An eight-year Finnish study of 260 young people found a different pattern, with greater reported screen time linked to better overall cognitive performance in adolescence. The important catch is that the study did not show screens caused those stronger results.
Researchers at the Universities of Jyväskylä and Eastern Finland say the findings challenge the idea that screen time should be viewed only as harmful. Their interpretation shifts attention toward what children actually do with their devices, while keeping physical activity firmly in the picture.
Following children from elementary school to adolescence
The analysis came from the Physical Activity and Nutrition in Children study, better known as PANIC, and was published in Pediatric Exercise Science. It included 124 girls and 136 boys, whose average age at the eight-year follow-up was 15.8 years.
Researchers assessed activity and sedentary behavior at the beginning, after two years, and again after eight years. A wearable Actiheart device combined heart-rate and movement measurements, while questionnaires captured screen time and different activities. This was not continuous electronic tracking of every hour spent on a phone or computer.
At the final visit, participants completed computerized CogState tests covering skills including learning, attention, and working memory. Working memory is the ability to hold information in mind while using it, much like remembering instructions while carrying out a task.
What the better scores actually tell us
Higher cumulative reported screen time was associated with better overall cognition in adolescence. That makes the result worth examining, but it is not the same as showing that adding an hour of gaming would improve a particular child’s abilities.
The researchers adjusted their analysis for factors including age, sex, parental education, and a childhood reasoning score. Still, the same detailed cognitive testing was not repeated throughout childhood, limiting what the team could establish about changes over time.
There is also the question of which way the relationship runs. Children with stronger existing thinking skills, or particular home circumstances, might use screens differently from other children. An observational association cannot fully separate those possibilities from an actual effect of screen use.
A screen can hold very different activities
“We should not regard screen time solely as harmful,” said lead author Petri Jalanko, a doctoral researcher at the University of Jyväskylä. In the university’s release, he encouraged parents and teachers to favor screen activities that involve active thinking, problem-solving, creativity, and learning.
Consider a child figuring out a digital puzzle compared with one watching a stream of autoplay videos. Both activities can register as an hour of screen time, but they are not interchangeable experiences. The Finnish study did not establish that either activity caused the cognitive differences it observed.
Its screen-time measure combined several uses, including television, videos, computers, video games, and mobile phones. That leaves an important question open about which activities, in which circumstances, might explain the association.
Exercise produced a more complicated picture
The activity findings were not simply a story of screens winning and exercise losing. More light-intensity physical activity was associated with better working memory among girls, while guided activity was associated with better working memory among boys, according to the university’s summary.
Less self-reported unsupervised activity was also linked to better performance on a working-memory measure. But some exercise associations weakened after statistical correction for multiple comparisons, and device-measured activity and sedentary time showed no overall association with cognition across the full group. These are not grounds for telling children to stop playing outside.
Measurement may help explain the mixed picture, the researchers suggest. A movement sensor can record how active someone is without revealing whether an activity involves strategy, cooperation, or other mental demands.
What parents can take from the findings
This study concerns cognitive test performance, not a blanket verdict on children’s sleep, mood, or overall well-being. It also does not establish an ideal daily screen allowance or demonstrate that the same pattern applies to every age group. Better scores in one area do not settle every question about digital life.
For families, Jalanko’s practical message is to balance physical activity with screen use that encourages thinking and learning. Rather than treating every digital minute as wasted, that approach invites a closer look at the activity itself. Is a child creating, solving something, or learning, and is there still room for movement away from the device?
The evidence supports asking those questions, not replacing one absolute rule with another. The press release was published on August 11, 2026, on the University of Jyväskylä website.
