The World Health Organization (WHO) and the American Academy of Pediatrics recommend no screen time before 18–24 months and less than one hour per day for children ages 2 to 5. Yet many young children exceed these limits, and evidence on how screen viewing affects cognitive development has been mixed. Most studies have been cross-sectional, focused on school-age children, or lacked repeated measurements across early childhood. Longitudinal studies spanning multiple developmental stages are therefore needed to identify potentially sensitive periods of exposure and better account for family and environmental influences.
A team of researchers from Inserm and the National University of Singapore conducted the study, which was published (DOI: 10.1007/s12519-026-01046-1) online ahead of print on April 9, 2026, in the World Journal of Pediatrics Using data from the Growing Up in Singapore Towards healthy Outcomes (GUSTO) birth cohort, they analyzed parent-reported screen time at six time points and assessed children’s academic achievement and working memory several years later.
The study followed 502 children from infancy through middle childhood and found that higher screen viewing time during certain developmental periods was associated with poorer later academic performance and weaker working memory. The associations were most consistent for screen exposure during infancy and around school-entry age, suggesting that these stages may represent particularly sensitive windows for cognitive development. Children with higher overall screen exposure across childhood also tended to perform less well academically. The findings indicate that the timing of screen use may matter as much as the total amount of exposure, with early childhood appearing to be a critical period when screen habits could have lasting implications for learning and memory.
"The effect sizes we saw at age 1 were the largest among all time points we examined," the authors said. "That suggests early infancy may be a window of heightened sensitivity, when the developing brain is particularly vulnerable to the displacement of learning interactions by screen time. We were also surprised to see that while screen use at age 2 and 3 did not show significant links, the associations re-emerged at age 6—when children enter formal schooling. So it is not just about early years; screen use later in childhood still matters."
The findings support the principle that "less is better" when it comes to children’s screen time, the authors said. While an individual child might not experience noticeable harm from an extra hour of daily viewing, even modest shifts at the population level could move a meaningful number of children toward lower academic performance. Public health interventions aimed at reducing screen time may benefit from starting early—during infancy—while also reinforcing limits around school entry age. The authors emphasize that future research should examine not only the duration of screen use but also factors such as content quality, device type, and parental co-viewing, which may influence developmental outcomes.
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References
DOI
10.1007/s12519-026-01046-1
Original Source URL
https://doi.org/10.1007/s12519-026-01046-1
Funding information
The GUSTO study was supported by the Singapore National Research Foundation and the Singapore Ministry of Health’s National Medical Research Council (NMRC/TCR/004-NUS/2008 and NMRC/TCR/012-NUHS/2014). Additional funding came from the Agence Nationale de la Recherche (ANR) in France (iSCAN project, ANR-20-CE36-0001).
About World Journal of Pediatrics
World Journal of Pediatrics (WJP) is a international, peer-reviewed academic journal dedicated to advancing pediatric medicine and child health. Published monthly, WJP publishes original research, reviews, and special reports covering all aspects of pediatrics. It welcomes contributions from pediatricians and researchers worldwide, focusing on the latest developments in pediatric clinical practice, pediatric surgery, preventive child healthcare, pharmacology, stomatology, and biomedicine, as well as basic and experimental sciences. The journal provides an global platform for academic exchange and dissemination of medical research findings. WJP currently has an Impact Factor of 7.3 and a CiteScore of 8.5.