Toddlers who spend too much time on devices like cellphones and tablets perform don’t perform as well on developmental tests later in their childhood, according to a new study. The tests considered performance in communication, motor skills, social skills, and problem-solving, in almost 2,500 children in Canada. Screen time included watching TV and videos, gaming, and using phones, tablets, or computers, according to CNN.
Officials in the US and Canada already recommend that children do not use screens before they are 18 months old. By age two, the children in the study were already spending as much as 17 hours on screens each week. This increased to 25 hours a week by age three, but dropped to 11 when they started school at age five.
“Higher screen time viewing at 2 and 3 years of age was associated with children’s delays in meeting developmental milestones at 3 and 5 years of age, respectively,” said Sheri Madigan, the study’s first author and University of Calgary childhood development assistant professor and research chair. “This study shows that, when used in excess, screen time can have consequences for children’s development. Parents can think of screens like they do giving junk food to their kids: In small doses, it’s OK, but in excess, it has consequences.”
According to the US National Library of Medicine, children in the US spend an average of five to seven hours a day starting at screens.
The paper was published in the journal JAMA Pediatrics on Monday.
The researchers believe that screen time takes away from time that children would otherwise be using to practice other abilities, including social and physical skills.
In the UK, there are no guidelines on limiting children’s screen time, and the College of Pediatrics and Child Health argues there is not enough evidence of a “direct toxic effect.”
“To our knowledge, the present study is the first to provide evidence of a directional association between screen time and poor performance on development screening tests among very young children,” the authors wrote.
The authors note that their study only shows correlation, and not a direct causal relationship.
They also acknowledged that they didn’t start monitoring screen time until children had reached two years of age, and missed out on additional data they could have gathered if they had started earlier. They note that it’s increasingly common for one-year-old babies to already start watching videos and using devices with screens.