Parents who are concerned about the emotional issues that can develop when young kids spend too much time in front of the television or tablet may be tempted to make screen time a special reward — for eating their vegetables, for picking up their room or waiting quietly while they finish an important phone call.

Unfortunately, this strategy doesn't work. Parents who use screen time as a reward — or take it away as a punishment — tend to have kids who spend more time glued to a screen, not less. “When you give food as a reward it makes children like the carrot less and the cake more. Same thing with screen time,” explained Jess Haines, the author of a study looking at the effect such parenting practices have.

Those children whose parents used access to screen time as a reward averaged 20 minutes more a day on their devices during the weekend.

Over 60 young children, from 18 months to five years of age, and 68 parents took part in the study. Haines and her University of Guelph colleague, Lisa Tang, chose the age group because the use of mobile devices like tablets and smartphones has soared among young children in recent years. And, as Tang put it, “this is the age when habits and routines become established and they tend to continue throughout life.”

Parents were questioned about how they monitored their children's screen time; the circumstances under which their kids were allowed to use mobile devices; and if they used their own phones, computers or tablets when they were around their children. Kids averaged nearly an hour and a half in front of a screen every weekday, the team found, and slightly more than two hours a day on weekends. Parents averaged two hours a day of screen time during the week and just over two and a half hours a day on weekends.

“We think the amount of screen time is higher on weekends because children are at home and typically have more interaction with their parents,” explained Haines.

Screen time is no friend to developing brains. It's worth noting that the Canadian Sedentary Behaviour Guidelines recommend less than one hour of recreational screen time per day for kids over two — and no time in front of a screen for children under two. Only 15 percent of Canadian preschoolers meet these guidelines, which are designed to help reduce rates of obesity.

It will not surprise parents to learn that a majority of the parents in the study reported they used screen time as a way to control behavior, especially on weekends. What was surprising is that those children whose parents used access to screen time as a reward averaged 20 minutes more a day on their devices during the weekend.

“It's possible the parent is allowing the child to be in front of a screen while they are,” said Haines. “For parents of younger children, this isn't as common because parents can have their screen time while a child is napping or in bed. But as children get older, out-grow their naps and have later bedtimes, spending time in front of a screen without children around becomes more difficult.”

Managing kids' screen time is an inescapable dilemma of modern parenthood. The rules will change as your child develops. Treating devices as a reward just adds to their allure. It is better to set clear and reasonable limits, and let kids know why screen time needs to be controlled. You need to model the behavior you want to see in your kids. Put your phone away during meals. Schedule dedicated family time, free of screens. Make it clear that you value person-to-person interaction.

The study is published in BMC Obesity.