Summary: A large longitudinal study shows that when children are exposed to screens matters as much as how much they use them. Researchers tracked 502 children from age 1 through age 8 and assessed viewing habits at six time points. Higher screen use during infancy (around 12 months) and again at school entry (around 6 years) predicted lower academic scores at age 9 and weaker working memory at age 10.5, while screen time at ages 2–3 showed little long-term effect.
The research highlights two sensitive windows in early development when screen exposure appears especially consequential: the first year of life and the transition into formal schooling. These findings suggest public health and parenting guidance should emphasize limiting screen exposure during those periods to support learning and memory development.
Key Facts
- Two vulnerable windows: The study found a U-shaped pattern of sensitivity — highest risk at infancy (age 1) and again at school entry (age 6), with mid-toddler years (ages 2–3) showing weaker long-term links.
- Infancy carries the greatest risk: Screen exposure at 12 months produced the largest negative effect sizes on later working memory and academic outcomes in the study.
- Displacement of interaction: Time spent watching screens in infancy likely displaces essential face-to-face, reciprocal interactions that foster language, attention, and memory networks in the rapidly growing baby brain.
- Working memory decline: Excessive screen use during the sensitive windows was associated with measurable reductions in working memory at 10.5 years — the cognitive workspace needed for reading comprehension, math, and complex problem solving.
- Population-level concern: While a single extra hour may produce only a small difference for an individual child, modest shifts across a population can move many children into lower academic brackets, creating a meaningful public-health impact.
Source: Zhejiang University
Background and purpose
As screens become almost ubiquitous in young children’s lives, parents and public health experts are increasingly concerned about long-term effects on learning. Prior research has been mixed and often cross-sectional or limited to older children. This study aimed to identify sensitive age periods by following the same children across early childhood and into middle childhood, controlling for family and environmental factors.
Study design and methods
Researchers used data from the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort. Parents reported their child’s daily screen viewing time at ages 1, 1.5, 2, 3, 6 and 8 years. Trained psychologists later evaluated academic achievement at age 9 (Wechsler Individual Achievement Test—Third Edition) and working memory at age 10.5 (Letter-Number Sequencing task from the Wechsler Intelligence Scale for Children—Fifth Edition). Multivariable linear regression models examined associations for each time point and for cumulative average exposure (N = 502 children).
Main findings
Average daily screen time rose from about 2.1 hours/day at age 1 to roughly 3.0 hours/day by age 8. In unadjusted models, higher screen exposure across ages 1–8 correlated with poorer academic performance at age 9 and weaker working memory at 10.5. After adjusting for potential confounders, the strongest persistent associations remained for screen time at age 1 (β = −1.47 standard points per additional hour/day for academic performance), 1.5 years (β = −0.95), and 6 years (β = −0.88). For working memory, screen time at age 1 (β = −1.12) and age 6 (β = −1.01) showed lasting negative associations. Cumulative average exposure across childhood predicted lower academic performance but did not show a significant cumulative association with working memory.
Interpretation and implications
The results suggest timing matters: early infancy appears to be a particularly sensitive window where screen use can replace critical interactive experiences that build the foundations of language, attention, and memory. The re-emergence of negative associations at school entry indicates that screen habits at this transition can interfere with adaptation to structured learning environments. The authors caution that even modest average increases in screen time can shift population-level academic outcomes, making reduced screen exposure a priority for public health efforts.
The study supports existing recommendations from organizations such as the World Health Organization and pediatric associations that advise minimal or no screen time for infants and limited viewing for preschoolers. The authors also note that future work should examine content quality, device type, and parental co-viewing — factors that may alter developmental risk.
Funding information
The GUSTO study received support from 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), with additional funding from the Agence Nationale de la Recherche (ANR) in France (iSCAN project, ANR-20-CE36-0001).
Key Questions Answered:
A: At about 12 months the brain undergoes intense synaptic growth and benefits most from rich, reciprocal human interactions. Screens are non-reciprocal and can displace face-to-face communication and hands-on exploration that are essential for early language, attention and memory development — a phenomenon described as the “displacement effect.”
A: The team expected early sensitivity but were surprised by the non-linear pattern: strong effects at age 1, little association at ages 2–3, and a renewed negative link at age 6 when children enter school. This suggests that screens can interfere both with foundational early development and with the brain’s adjustment to formal learning environments.
A: Not necessarily in a dramatic or immediately visible way for an individual child. The authors emphasize the public-health perspective: small average increases in screen time across many children can meaningfully lower population-level academic outcomes, pushing a substantial number of children into lower performance categories.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- Journal paper reviewed in full.
- Additional context added by our staff.
About this neurodevelopment and memory research news
Author: Editorial Office
Source: Zhejiang University
Contact: Editorial Office – Zhejiang University
Image: The image is credited to Neuroscience News
Original Research: Open access. “Screen viewing time from age 1 to 8 years and subsequent academic performance and working memory” by Shuai Yang et al., World Journal of Pediatrics. DOI: 10.1007/s12519-026-01046-1
Abstract
Screen viewing time from age 1 to 8 years and subsequent academic performance and working memory
Background
Screen viewing time has been linked to children’s cognitive and academic outcomes, but there are few longitudinal studies that can identify the most sensitive developmental periods. This study examined both single time-point and cumulative average screen exposure in relation to academic achievement and working memory.
Methods
Parents in the GUSTO birth cohort reported child screen time at ages 1, 1.5, 2, 3, 6 and 8 years. Academic performance at age 9 and working memory at age 10.5 were measured by trained assessors. Multivariable linear regression analyzed associations for 502 children.
Results
Average screen time rose from about 2.1 hours/day at age 1 to 3.0 hours/day at age 8. Unadjusted models showed consistent associations between higher screen time across ages 1–8 and poorer academic and working memory outcomes. After adjustment, screen time at ages 1, 1.5 and 6 years remained associated with lower academic performance at age 9, and screen time at ages 1 and 6 years remained associated with poorer working memory at age 10.5. Cumulative average exposure predicted lower academic performance but not working memory.
Conclusion
Cumulative average screen viewing time across childhood was linked to lower academic performance, while single-timepoint exposure in early infancy showed the strongest associations with later outcomes. These results underscore the importance of limiting early screen exposure and monitoring screen habits at school entry to support cognitive and academic development.