Release time: 2020-03-14 17:25

Can Early Screen Limits Improve Future Healthy Behavior ?

A new study examines the link between toddler screen time and exercise.

The link between screen time in children and a whole array of negative outcomes including obesity, attention problems, sleep problems, and aggression remains controversial both within the public and among child development experts.

To be fair, it isn’t exactly the link that people argue over but rather the idea that screen use actually causes these things. Lots of studies that measure screen use and something else like ADHD behavior find a statistically significant correlation but these kinds of studies can’t solve the proverbial chicken versus the egg question of what begets what. Prospective studies that follow a whole group of kids over time are better but still not definitive.

A recent prospective study added a new wrinkle to the debate by looking at children when they still were toddlers. From the Growing Up in Singapore Towards Healthy Outcomes study (or GUSTO), the amount of screen time kids spent on various devices when they were between 2 and 3 years old was assessed through parental questionnaires. This younger age group is important as presumably the amount of time the kids spent on screens had a lot to do with the parents, many of whom are making the choice to limit the exposure. These parent-induced habits that are being learned very early in life might then carry forward to later years when children have more control over their screen use.

When children were around 5 1/2 years old, a number of parameters were measured, including sleep and their level of physical activity over an entire week. The latter was assessed using wrist-worn accelerometers—another plus of this study relative to those that just ask parents about their child’s level of physical activity. Of specific interest to the researchers were the amount of sleep, sedentary behavior, and quantity of various types of physical activity (light versus moderate to vigorous).

In terms of results, significant correlations were found between total screen time at age 2-3 and lower amounts of sleep, light physical activity, and moderate to vigorous activity at age 5. When the researchers divided up screen time into those with low levels at age 2-3 (less than one hour per day) and high levels (three or more hours/day), those with high screen use were found to have approximately 40 minutes more of sedentary behavior per day at age 5, 25 minutes less per day of light activity, and 13 minutes less per day of more vigorous activity.

The researchers reported that their data support the idea of displacement—basically, the idea that screen use takes time away from doing healthier activities like running around or sleeping. The authors made the recommendation, based on their data, that parents should try to limit screen time in early childhood under the idea that these early-forming habits impact behavior later in life. 

As much as I’d like to believe this, however, this conclusion is a bit of a stretch from what they actually can say. Why? Because it is also quite possible that the parents remain quite involved in setting screen limits when a child is 5 years old and it is the current limit setting, not the habits learned as a toddler, that are driving the current differences in screen use.

Unfortunately, we just don’t have a good study yet (as far as I know) that can with more certainty tell parents that if you put in the considerable effort to teach responsible screen use early in life that the payoff later will be someone who can better regulate screens on their own. We need this study, and it wouldn’t be impossible to do, although one would probably need to find a group of parents willing to be randomized regarding how they limit their child’s screen use for a while. Any takers?  Alternatively, a researcher could compare siblings brought up under different rules about screens.

As schools cancel and “social distancing” widens, many parents are going to feel the pressure to fill in a lot of downtime with screens. These are trying times right now and parents need to do what they need to do. Over the long-term, however, helping children find alternatives to screens at early ages may increase their engagement in body and brain-healthy activities and help avoid those looks of complete horror and bewilderment when confronted with the need to do something not related to a screen.

David Rettew M.D.

ABCs of Child Psychiatry

David Rettew, M.D., is a child psychiatrist at the University of Vermont and author of Child Temperament: New Thinking about the Boundary between Traits and Illness.

In Print: 

Child Temperament: New Thinking About the Boundary Between Traits and Illness (Norton Professional Book)

Psychology Today