More time spent in front of screens in early childhood and at the start of schooling was associated with poorer academic performance and weaker working memory years later. These findings suggest that early childhood may contain particularly sensitive periods when screen habits may have longer-lasting consequences.
A new longitudinal study that tracked children from 1 to 8 years old found that more intensive screen viewing, especially in early childhood and around the time children start school, was associated with lower academic achievement at age 9 and weaker working memory at age 10.5. The results suggest that the timing of when children are exposed to screens may be as important as the amount of time they spend on them.
Tracking screen time from infancy to school age
The World Health Organization (WHO) and the American Academy of Pediatrics recommend avoiding screen use until 18-24 months and limiting it to less than one hour per day for children aged 2 to 5 years. However, many children spend more time in front of screens than these guidelines recommend. Studies on the impact of screen viewing on cognitive development have yielded mixed results. Much of the previous work relied on snapshots taken at a single point in time, focused primarily on school-aged children, or lacked repeated measurements throughout early childhood.
Researchers from Inserm and the National University of Singapore conducted this study, which was published in the World Journal of Pediatrics. Using data from the birth cohort Growing Up in Singapore Towards healthy Outcomes (GUSTO), the team examined parent-reported screen viewing time data at six different age points. These measurements were then compared with the children’s academic performance and working memory several years later.
The analysis included 502 children who were followed from infancy to middle childhood. Higher levels of screen viewing at certain developmental stages were associated with poorer academic outcomes and weaker working memory later on. The clearest patterns were seen for screen exposure in early childhood and at the start of formal schooling, suggesting that these periods may be particularly sensitive for cognitive development.
Age 1 showed the strongest association
“The effect sizes we observed at age 1 were the largest among all the time points we examined”, the authors noted. “This suggests that early childhood 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 ages 2 and 3 did not show significant associations, the links reappeared at age 6 — when children enter formal schooling. So, it’s not just the early years; screen use in later childhood still matters.”
This pattern was not identical at every age. Screen viewing at ages 2 and 3 was not significantly linked to later outcomes measured in the study, but the association reappeared at age 6. This time coincides with the transition to formal education, when children face increasing demands on attention, memory, and learning.
The researchers said the findings support the general principle that “less is better” for children’s screen exposure. An additional hour of viewing per day may not show an obvious effect in every individual child, but relatively small shifts across an entire population could still move a significant number of children toward poorer academic outcomes.
Efforts to reduce screen viewing time may be most effective if they begin in early childhood and are reinforced as children approach school age. The researchers also caution that screen time duration alone does not capture the full picture. Future studies should examine whether developmental outcomes differ based on the quality of the content children watch, the type of device used, and whether parents watch together with their children.
The GUSTO study was supported by the Singapore National Research Foundation and the National Medical Research Council of the Singapore Ministry of Health (NMRC/TCR/004-NUS/2008 and NMRC/TCR/012-NUHS/2014). Additional funding came from the National Research Agency (ANR) in France (iSCAN project, ANR-20-CE36-0001).
The authors of the article “Screen viewing time from age 1 to 8 years and subsequent academic performance and working memory”, published in World Journal of Pediatrics, 2026; 22 (5): 522, are Shuai Yang, Natarajan Padmapriya, Seang-Mei Saw, Yap Seng Chong, Lynette P. Shek, Peter D. Gluckman, Keith M. Godfrey, Johan G. Eriksson, Falk Müller-Riemenschneider, Evelyn K. Law, and Jonathan Y. Bernard.
Source: Zhejiang University
