Prolonged Screen Time Associated with Developmental Delays in Young Children

A new study links the amount of screen time spent by one-year-olds to developmental delays in problem-solving and communication at the ages of two and four.

Published in JAMA Pediatrics, the study was led by researchers from Tohoku University in Sendai, Japan, with collaborators at Hamamatsu University School of Medicine in Hamamatsu, Japan. According to a study published in 2022, only one in four children meet the American Academy of Pediatrics’ screen time guidelines, which suggest avoiding screens for one-year-olds and limiting screen time to one hour for two to five-year-olds. For this investigation, researchers aimed to explore the potential developmental consequences of excessive screen time in young children.

Researchers examined over 7,000 mother-child pairs participating in the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study. Approximately half of the children were boys, and the other half were girls. The children's screen times were assessed through parental questionnaires, which covered viewing televisions, video game displays, tablets, mobile phones, and other electronic devices.

The children were placed into four categories according to their screen time: less than one hour, from one to less than two hours, from two to less than four hours, and four or more hours. The children’s development was assessed at the ages of two and four through the five domains of child development, including communication, gross motor, fine motor, problem-solving, and personal and social skills.

Using statistical analysis, researchers compared the amount of screen time the children got with their scores on the developmental assessments. According to the study, the data revealed a dose-response association, indicating that the children's level of developmental delay was correlated to their daily dose, or amount, of screen time.

The study found that increased screen time was associated with developmental delays in all five domains of development besides gross motor skills at age two. By age four, the analysis linked increased screen time to developmental delays only in communication and problem-solving.

According to Obara, PhD, Tohoku University epidemiologist and corresponding author of the study, these results indicate a link between screen time and development delays. In addition, he said that the study suggests that screen time may impact developmental areas differently, and future research should continue to study the domains separately.

"The rapid proliferation of digital devices, alongside the impact of the COVID pandemic, has markedly increased screen time for children and adolescents, but this study does not simply suggest a recommendation for restricting screen time. This study suggests an association, not causation between screen time and developmental delay," said Obara. "We use the term 'delay' in accordance with previous research, but it is debatable whether this difference in development is really a 'delay' or not. We would like to gain deeper insight in future studies by examining the effects of different types of screen exposure."