ADVERTISEMENT

Kids on Screen-Time Diet Lost Weight and Got Better Grades

Over the long term, limiting screen time brings substantial benefits
too much tv


Too much TV leads to many problems
Credit: Thinkstock

Parents are in a much more powerful position than they realize.

A new study of over 1300 3rd to 5th graders found that parental monitoring of children’s media has ripple effects that extend across several different areas of children’s lives out into the future.  For this study, my colleagues and I talked to children, their parents, their teachers, and even their school nurses, once at the beginning and once at the end of a school year. e asked parents whether they set limits on the amount of screen time their children were allowed to have each day, and also on the content of media their children were allowed access to. As one might expect, setting limits on the amount and content of children’s media is generally effective at reducing time on TV and video games and at reducing violent media exposure. 

However, seven months later we got a huge surprise.  Children whose parents set more limits on the amount and content of media were now getting more sleep, had gained less weight (lowering their risk of obesity), were getting better grades in school, exhibited more helpful and cooperative social behaviors in school, and were less aggressive with their peers (as seen by the classroom teachers).

Reducing total screen time increases children’s amount of sleep, which in turn lowered their weight gain.  Reducing total screen time also led to higher school performance, more prosocial behavior, and lower aggressive behavior (standardized regression weights between .08 and .22).  Reducing media violence exposure had additional (and larger) benefits for increasing prosocial behavior and lowering aggressive behavior. These effect sizes are generally considered to be in the small to medium range (See Figure 2 from the article). 

Parents often say that they feel out of control—technology is constantly changing and children “get” it easier than their parents.  This makes the parents feel like they’re not really having any impact. This study demonstrates that, on the contrary, parents are having much farther reaching effects than they know.

No parent will be able to see that their child gained less weight, got better grades, or was less aggressive than he otherwise would have been.  You can’t see what didn’t happen.  Also, because it is a slow accumulation across time, you won’t see any immediate benefits.  When you tell your child that they can’t have a particular video game because of its content or that they have reached their limit of screen time for today, you won’t see their grades improve tomorrow. You won’t see them behave better tomorrow. (Actually, you might see a lot of complaining instead).  Nonetheless, this study demonstrates that setting and enforcing limits on both time and content has powerful benefits for children’s school performance, physical health, and social outcomes. This is particularly surprising because these are all very different types of outcomes, but being involved in children’s media habits has a measureable impact on all of them out into the future!

Armed with this knowledge, parents should hopefully feel more confident about setting clear limits on children’s media use. Because there are now so many more types of media than ever before in history, most researchers are beginning to think in terms of “total screen time” rather than focusing just on television, video games, or computers.  So add up all the time your child watches TV, DVDs, iPad, Facebook, and plays video games on consoles, computers, or handheld screens (don’t count time that is for school use – that’s free!).  When asked, “How much is too much?” I think the American Academy of Pediatrics has a good set of recommendations.  They recommend that elementary school children spend no more than one hour of total screen time a day, and no more than two hours a day for secondary school children.  They also recommend no screens in children’s bedrooms, as this greatly increases the amount of time children spend on screens (and it also predicts poorer school performance). 

Our study did not seek to measure the mechanisms through which all of these benefits accrued, but we can speculate based on other research.  One reason screen time matters is through the activities it displaces.  Every hour in front of electronic screens is an hour not doing homework, reading, exploring, being active, or going to bed.  This displacement helps to explain the effects on sleep, weight gain, and school performance.   Many hundreds of studies have also shown that media content matters. Educational TV and games teach, but so do shows and games not specifically designed to teach. Humans are such good learners, we can learn just by seeing something once. If we see or do it repeatedly, however, we learn it to the point that it becomes automatic.  For example, parental limits on R-rated movies lowers the risk of children drinking and smoking.  Many meta-analyses (the most comprehensive of which included over 130 studies) have shown that media violence is a risk factor for aggression and decreases prosocial behavior.

Ultimately this is all good news – it means that parents have much more power to help their children grow up healthy and socially adjusted than they realized.

Are you a scientist who specializes in neuroscience, cognitive science, or psychology? And have you read a recent peer-reviewed paper that you would like to write about? Please send suggestions to Mind Matters editor Gareth Cook, a Pulitzer prize-winning journalist at the Boston Globe. He can be reached at garethideas AT gmail.com or Twitter @garethideas.

Rights & Permissions
Share this Article:

Comments

You must sign in or register as a ScientificAmerican.com member to submit a comment.
Scientific American Back To School

Back to School Sale!

12 Digital Issues + 4 Years of Archive Access just $19.99

Order Now >

X

Email this Article

X