Researchers from the University of Jyväskylä in Finland tracked children's physical activity, sedentary behaviour, and screen time from childhood into the teenage years, then measured how well their brains processed information during adolescence. The study is notable because it followed the same children over 8 years, giving a longer view than most screen time research.
The main finding challenges the common idea that all screen time harms children's brains: children who spent more time on screens as they grew up actually showed better cognitive processing (the speed and accuracy of thinking) as teenagers.
What matters most is what children do on screens
The researchers were careful to note that not all screen time works equally. The benefit appeared linked to screen activities that demand active thinking—learning, problem-solving, creativity, and other forms of mental engagement. Watching passive content, by contrast, may not offer the same advantage. Doctoral Researcher Petri Jalanko explained that "teachers and parents should encourage children to use devices and screens in such ways that promote active thinking, problem-solving, creativity and learning."
This distinction is important for Singapore families deciding screen policies. It suggests the question shouldn't be simply "how much screen time?" but "what is my child actually doing on the device?" A child coding, creating digital art, or solving puzzles may benefit differently from one passively consuming videos.
Physical activity's relationship to thinking is more complex—and differs for girls and boys
The physical activity findings were less straightforward. Among girls, gentler, everyday movement (like walking or light play) since childhood linked to better working memory—the ability to hold and manipulate information in the mind. Among boys, structured, guided physical activity from childhood onwards showed the same connection.
Unexpectedly, unsupervised exercise showed the opposite pattern: children who reported less unstructured, self-directed physical activity performed better cognitively. The researchers did not fully explain this finding, so its meaning remains unclear.
These differences between girls and boys suggest that one-size-fits-all activity recommendations may miss something real about how children's brains develop differently.
Move toward purposeful screen use, not elimination
- Choose screen activities that demand thinking—coding apps, digital creation tools, or educational games—over passive viewing for cognitive benefits.
- For girls, build consistent gentle daily movement into routines; for boys, consider structured activity classes or coached sports.