One in four Canadian children are not developmentally ready for school by the time they start kindergarten, and a new study suggests excessive screen time may be a key contributor.
The study, published in the journal JAMA Pediatrics on Monday, found toddlers and preschoolers who spent high amounts of time in front of televisions, computers and other digital devices were less likely to reach various milestones for communication skills, motor skills and problem-solving by age five.
“We’re seeing that screen time is creating some disparities in children’s development over time,” says lead author Dr. Sheri Madigan, assistant professor in the department of psychology at the University of Calgary.
The study adds to a continuing debate over whether frequent use of video games, televisions and other digital media actually harms children’s health and ability to learn.
Earlier this month, Britain’s Royal College of Paediatrics and Child Health released its guide on screen time for clinicians and parents, stating there is “essentially no evidence” to support the popular idea that screen time is directly “toxic” to one’s health. It provided no recommended time limits on children’s use of digital devices, noting that the impact of screen time on young people’s well-being was small, when considering other factors, such as sleep, physical activity, eating, bullying and poverty.
Dr. Madigan, who holds the Canada Research Chair in the determinants of child development, notes that others have suggested children with developmental delays are more likely to be given screen time as a way to cope with challenging behaviours, not that screen time leads to delays.
She says her study provides some clearer answers to this “chicken or egg question," and indicates that excessive screen time is likely a key contributor to recent research findings that show one-quarter of Canadian children are ill-prepared for learning when they begin school.
“We can’t say that increased screen time causes delays in child development, but I think we get as close as we can, in an observational study, [to] saying that there is a link here," she says. "And it’s something we really need to pay attention to.”
Dr. Madigan and her team examined data from a long-running project called the All Our Families study, which has been tracking thousands of Calgary mothers and their children, starting from pregnancy, since 2008. They analyzed how much screen time the children received, and how they fared on developmental screening tests, at ages two, three and five.
These tests included measures of their communication skills (for instance, forming full sentences), gross motor skills (running and walking), fine motor skills (tying shoelaces or copying letters), as well as problem-solving, and personal and social skills (serving themselves food).
More than 2,400 children were included in the analysis.
The study showed the children were watching television or using digital devices for an average of 2.4 hours a day at age two, 3.6 hours at age three, and 1.6 hours at age five. That far exceeds the maximum one hour of screen time per day for children, ages two to five, recommended by the Canadian Paediatric Society.
While the study did not examine why screen time may be detrimental, the researchers suggest it cuts into time that could otherwise be spent practising and mastering various skills. For instance, young children may be missing opportunities to practise walking or to interact with their caregivers.
In an e-mail, Dr. Max Davie, officer for health promotion for the Royal College of Paediatrics and Child Health in Britain, said the latest study shows only “a weak association between screen time and developmental outcomes."
In fact, Dr. Davie adds, “the data shows that the association with screen time is weaker than that between developmental outcomes and good sleep, reading to the child, and maternal positivity.”
Dr. Madigan, however, is not taking any chances with her own children. As a mother of four, the youngest of which are two-year-old twins, she tries to keep their screen time to a minimum: four hours total on weekends, and on most weekdays, none at all.