What limits should we set to children's exposure to new media?

As most parents know by now, the experts say we should limit our kids' screen time or risk raising socially stunted couch potatoes. Last autumn, the American Academy of Pediatrics (AAP) released guidelines for children and adolescents, recommending no more than two hours per day of any type of entertainment screen time for children aged three to 18, and none for those two or younger.

The guidelines cover the internet and texting as well as television, movies and video games.

As a science writer, I wondered how the AAP decided on that limit, which seems arbitrary and simplistic. As a mother raising a three-year-old and a six-year-old in a house full of glowing screens, I wondered, how would I ever enforce it?

Victor Strasburger, who is a professor of paediatrics at the University of New Mexico in Albuquerque and an AAP spokesman, says the two-hour cut-off comes from several large studies that have followed the television-watching habits and health of children over decades.

"Over two hours per day, and the more time spent in front of a screen, the higher the risk of obesity," he says.

With more than two hours of screen time per day, children are more likely to experience a drop in school performance and increased aggression, Strasburger says.

"If you are spending seven hours with media, those are hours you are not walking the dog, playing on the soccer team, or hanging out with friends."

Recent studies followed thousands of European preschool and school-age children linked screen time to emotional and family problems, and lack of sleep.

There is not much research yet to determine if different types of screens are worse for a child's development than others, but a large recent study highlights differences between television-watching and game-playing: more than three hours per day of television was linked to worse conduct, but the same stretch of video gaming was not.

AAP spokeswoman Marjorie Hogan advises families to cultivate a "healthy media diet" with all things in moderation.

"It starts when kids are very, very small," she says. Families should determine which media they will use, and things like whether the television should be turned off when not in use. "Remember, diet is not only the choice you make, but also the amount of programming," Hogan says.

When it comes to teens, the challenge may be greater: 77 per cent of 12- to 17-year-olds own cellphones, and the average teenager sends more than 3,300 text messages a month, according to a 2011 study.

"The multitasking aspect for teens is huge," says Megan Moreno, director of the social media and adolescent health research team at Seattle Children's Research Institute.

Her group found that older teens spend more than half their time online multitasking, with typically four applications open simultaneously.

That may not sound a lot, but it is to adolescents who are still developing their cognitive and social skills.

The newness of new media means not much is known about its health impact on teens, Moreno says. Children aren't complaining about Facebook-induced headaches, she says, but in surveys college students have noted weight loss or gain, lost sleep, and vision problems because of internet use.

How well do the AAP guidelines translate to new media? "We don't have that answer yet," Moreno says, adding that it may be more appropriate to increase screen time to up to four hours per day for older teenagers.

Worries that children will encounter explicit content on the internet, or strike up relationships with strangers, are misplaced, say Moreno and Michele Ybarra, the research director at the Centre for Innovative Public Health Research in San Clemente, US.

Most children use the internet to "extend their face-to-face relationships", says Ybarra. When surveyed, only 3 per cent to 6 per cent per cent of 10-to-15-year-olds had knowledge of violent and sexually explicit sites.

To ensure a healthy media diet, experts suggest developing a family media plan:

• Enforce consistent rules about screen time from the start.
• Keep all screens and internet devices out of the bedroom.
• Impose mealtime restrictions and bedtime curfews for everyone's devices.
• Watch or explore media content with children.

Ultimately, media usage isn't inherently good or bad. Parents should sit, view and discuss content with children, especially if media messages conflict with family beliefs or house rules, experts say.

The Washington Post