New data show early exposure hits hardest on learning and memory years later.
Babies who clock more screen time in their first year tend to lag in academic tests and working memory by ages 9 and 10. A long-running Singapore study has now pinpointed infancy and the start of school as the most sensitive windows.
Researchers tracked 502 children in the Growing Up in Singapore Towards healthy Outcomes (GUSTO) birth cohort. Parents reported daily screen time at ages 1, 1.5, 2, 3, 6 and 8. Psychologists later tested academic skills with the Wechsler Individual Achievement Test at age 9 and working memory with a letter-number sequencing task at age 10.5.
Strongest signal at age 1
After adjusting for family and social factors, each extra hour of screen time at age 1 linked to a 1.47-point drop in academic performance scores. Effects also appeared at 1.5 years and again at age 6. Working memory suffered most from higher exposure at ages 1 and 6. Cumulative screen time across childhood predicted poorer academics overall, though the infancy window produced the largest effect sizes.
Average viewing rose from about 2.1 hours a day at age 1 to 3 hours by age 8. The pattern held even after controls, though effect sizes shrank. Screen use at ages 2 and 3 showed weaker or no clear long-term links, creating a U-shaped sensitivity curve.
Why timing matters
The authors note that early infancy is a period of rapid brain wiring. Screens can crowd out face-to-face talk, play and responsive caregiving that build the foundations for attention and learning. The rebound at school entry may reflect how habits form just as formal demands rise.
“The effect sizes we saw at age 1 were the largest among all time points we examined,” the research team stated. “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.”
Guidance and limits
The findings align with long-standing advice from the World Health Organization and American Academy of Pediatrics: avoid screens before 18 months except for video chats, and keep high-quality content under one hour a day for ages 2–5. The study does not prove screens alone cause the gaps. Content quality, co-viewing and other family factors still need closer study. Yet even modest population-level reductions could shift many children toward stronger outcomes.
AI Disclosure: This article was created with the assistance of artificial intelligence tools and was reviewed and edited by the Glowls News editorial team before publication.