Daily Screen Time Linked to Developmental Delays in Toddlers

3 min read

Aug. 23, 2023 – One-year-olds who had an hour or more of daily screen time were up to five times more likely to miss milestones for communication skills when they reached 2 years old, according to a new study from Japan.

While screen time research has previously shown varying impacts on development and gaining new skills, including in some cases benefits based on what type of programming is watched, this latest study sought to identify whether specific developmental areas were affected by screen time at an early age.

Screen time was defined as the amount of time spent watching television, playing video games, or using mobile phones, tablets, or other electronic devices. 

The study was published this week in the journal JAMA Pediatrics. Researchers analyzed data for 7,097 children born in Japan whose mothers provided ongoing updates to a databank for research purposes. The research program recruited pregnant women between 2013 and 2017 to contribute data about their children.

The researchers analyzed how much screen time the mothers said their children had each day as 1-year-olds, and that information was linked to the mothers’ later reports on whether their children had met developmental milestones as 2-year-olds. To understand how much screen time children had as 1-year-olds, the mothers were asked: “On a typical day, how many hours do you allow your children to watch TV, DVDs, video games, internet games (including mobile phones and tablets), etc.?”

When the children were ages 2 and 4 years old, the mothers were also asked a battery of standardized development questions known as the Ages & Stages Questionnaire. Some of the communication questions asked whether the child imitates a two-word sentence, such as “mama eat,” or whether a child can point to a correct picture without being shown, such as “where is the dog?”

The researchers found that when considering daily screen time while a child was 1 year old, those who had 1 hour per day of screen time or more were more likely to have developmental delays in communication skills as 2-year-olds, compared to 1-year-olds who had less than an hour of daily screen time.

Specifically, the study showed that 2-year-olds were:

  • 61% more likely to have communication developmental delays if they had 1 to less than 2 hours of daily screen time as 1-year-olds
  • Twice as likely to have communication developmental delays if they had 2 to less than 4 hours of daily screen time as 1-year-olds 
  • Five times more likely to have a communication developmental delay if they had 4 or more daily hours of screen time

The study also showed that children who had an hour or more of screen time daily as 1-year-olds were more likely to miss milestones as 2-year-olds in fine motor skills, personal skills, and social skills. But the children were not more likely to miss milestones in those areas as 4-year-olds.

The authors noted that it is difficult to limit screen time in the modern world. The American Academy of Pediatrics (AAP) discourages screen time for children under 18 months old other than video chatting. 

“Evidence is sufficient to recommend time limitations on digital media use for children 2 to 5 years to no more than 1 hour per day to allow children ample time to engage in other activities important to their health and development and to establish media viewing habits associated with lower risk of obesity later in life,” the AAP’s policy on Media and Young Minds states. “In addition, encouraging parents to change to educational and prosocial content and engage with their children around technology will allow children to reap the most benefit from what they view.”

The AAP reports that at 15 months old, children are able to learn words from touchscreens, but have trouble transferring that knowledge to the real world. Two-year-olds can learn words from live video chatting with a responsive adult, the AAP reports.

“The chief factor that facilitates toddlers’ learning from commercial media (starting around 15 months of age) is parents watching with them and reteaching the content,” the AAP advises.