Summary: In a large U.S. cohort, children who spent more time than average playing video games showed an increase in measured intelligence—about 2.5 IQ points more than peers—while time spent watching television or using social media showed no clear impact on cognitive gains.
Source: Karolinska Institute
Researchers at Karolinska Institutet in Sweden examined how different types of screen use among children relate to changes in cognitive ability over time.
The study tracked U.S. children’s everyday screen habits—time spent watching TV and videos, using social media, and playing video games—and analyzed how those habits were associated with changes in general cognitive ability between ages nine or ten and two years later.
Published in the journal Scientific Reports, the analysis indicates that greater-than-average video-game play was associated with modest but measurable improvements in intelligence, while television viewing and social media use showed no reliable positive or negative effects in this sample.
Screen exposure is an increasingly prominent part of childhood, and its impact on development and cognition remains a topic of public and scientific debate. To clarify these relationships, investigators from Karolinska Institutet and Vrije Universiteit Amsterdam leveraged longitudinal data to control for baseline differences and potential confounders.
The research included more than 9,000 children from the United States. At baseline (ages nine to ten), participants completed a comprehensive set of standardized cognitive tests to estimate general intelligence. Parents and children also reported typical daily hours spent on three categories of digital media: watching TV and videos, engaging on social media, and playing video games.
Two-year follow-up and rigorous controls
About 5,000 of those children were reassessed after two years, repeating the same cognitive measures. By comparing scores across the two time points and accounting for each child’s starting performance, the researchers were able to estimate how changes in test performance related to differing screen habits over the interval.
Importantly, analyses controlled for genetic differences linked to cognitive ability and for socioeconomic factors, including parents’ education and household income, to reduce the influence of background variables that can confound observational findings.
On average, children in the study spent roughly 2.5 hours per day watching TV or videos, about 30 minutes on social media, and around 1 hour playing video games.
After two years, the group of children who played video games more than the average showed an additional increase in measured intelligence of approximately 2.5 IQ points compared with the average change. No consistent positive or negative links were found for TV viewing or social media use in the primary analyses.
“We did not study how screen activities affected physical activity, sleep, overall well-being, or school grades, so our results speak specifically to cognitive change,” says Torkel Klingberg, professor of cognitive neuroscience at the Department of Neuroscience, Karolinska Institutet.
Klingberg adds that the findings support the view that screen time, in general, does not necessarily harm children’s cognitive development and that video-game play may provide cognitive stimulation that contributes to modest gains in intelligence. These observations align with several experimental studies reporting cognitive benefits associated with certain types of video-game training.
Intelligence is dynamic and influenced by environment
The results reinforce a growing body of research showing that intelligence is not an immutable trait; instead, cognitive abilities can change in response to environmental experiences and activities. The investigators note that structured cognitive training, enriched environments, and broader societal effects (for example, the Flynn effect) demonstrate similar malleability.
The team plans to extend this line of work by examining other environmental influences and by linking cognitive changes to childhood brain development measures to better understand mechanisms behind observed effects.
The authors acknowledge several limitations. The sample reflects U.S. children only, and the study did not distinguish between types or genres of video games, which limits how broadly the findings can be generalized to populations with different gaming patterns. Screen-time measures were self-reported, introducing the possibility of reporting error. Finally, some associations varied depending on how socioeconomic factors were modeled in secondary analyses.
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Author: Press Office
Source: Karolinska Institute
Contact: Press Office – Karolinska Institute
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Original Research: Open access. “The impact of digital media on children’s intelligence while controlling for genetic differences in cognition and socioeconomic background” by Bruno Sauce et al., Scientific Reports
Abstract
The impact of digital media on children’s intelligence while controlling for genetic differences in cognition and socioeconomic background
Digital media are central to modern childhood, yet their cognitive effects remain debated. Studies that include genetic information can help clarify causal inferences by accounting for genetic predispositions that often go unmeasured.
This study estimated how distinct types of screen time—watching videos, socializing online, or gaming—relate to changes in children’s intelligence while controlling for genetic factors and socioeconomic background.
We analyzed 9,855 U.S. children from the ABCD dataset who had intelligence measures at baseline (ages 9–10) and again after two years. At baseline, time spent watching videos (r = −0.12) and socializing online (r = −0.10) showed small negative correlations with intelligence, while gaming showed no baseline correlation.
Across the two-year follow-up, gaming was associated with positive gains in intelligence (standardized β = +0.17), whereas social media use showed no effect. In the main analysis, watching videos also showed a positive effect (standardized β = +0.12), although this association was not robust when parental education was used instead of a broader socioeconomic index in a post hoc test.
Overall, these results are consistent with evidence that cognitive abilities are malleable and can be influenced by environmental experiences, including structured cognitive activities and media exposure.