Can TV now hurt a baby’s chance of later success in school?

by Boston Children's Hospital staff on May 14, 2010

Michael Rich, MD

Michael Rich, MD, MPH

Last week Rich answered a question about kids being addicted to cell phones. This week he discusses a recent study that indicated children who watch too much TV as toddlers could face health and school problems later on in life.

TV as teacher, TV as companion, TV as babysitter. Nearly half of all children under age 2 watch TV and 41 percent of preschoolers exceed expert recommendations for TV time. We have all done it – to help our children learn the ABCs or just to buy some time to make them dinner. But we have felt uneasy about it. In the short term, it gets the job done, but in the long term, does it help our babies or harm them?

Research shows that parents are evenly split on their opinions of the effects of TV on children – 1/3 think it helps, 1/3 says no difference, 1/3 think it hurts them. Now we have some solid evidence to guide our decision-making.  A new study from Canada followed 1,314 children from the age of 5 months to 10 years, looking at their TV viewing at ages 2½ and 4½ years and seeing where they were physically, emotionally and academically at 10 years old. What they found was concerning. For each hour of TV watched at 2½, there were increases in consumption of soft drinks (9 percent) and snacks (10 percent), decreases in physical activities (9 percent) and weekend sports (13 percent) and increases in body mass index (5 percent).There were emotional repercussions, as well – children were 10 percent more likely to be victimized by classmates for each hour of toddler TV.

Finally, 10-year-olds showed a 6 percent decrease in math achievement and 7 percent decrease in classroom engagement for each hour of TV at 2½. While these outcomes are usually attributed to multiple influences, researchers controlled for many known factors and TV viewing still had an independent effect.

Cute kid watching tvIt must be noted, however, that other studies show TV content matters. Compared to children who watch entertainment programming, preschoolers who watch limited amounts of developmentally appropriate programming are more prepared on entering school and demonstrate higher academic achievement right through high school. While parents’ uneasiness about their toddlers and preschoolers watching TV appears well-founded in the increased risks to physical, psychological and academic well-being, viewing one or two hours of quality educational programming daily after the age of 2 may be okay.

2 comments

  • Bronwyn Fleet

    I don’t understand the key finding of this study … “every additional hour of television exposure at 29 months corresponded to 7% and 6% unit decreases in classroom engagement (…) and math achievement (…) respectively…”

    Does this mean additional hours per day, per week, per month or total and above zero, above the mean or above the recommended max. of 2 hours per day? And what is a percentage unit decrease … does this simply mean a decrease in these ratings at age 10. If so I don’t understand how 6-7% per additional hour of TV watched (whatever this means) at age 2.5 can be described as modest.

  • http://www.askthemediatrician.org Dr. Michael Rich

    Dear Bronwyn,
    Here’s a little more information that might make the results more clear. In their attempt to make their findings understandable to the general public, the researchers correlated average screen use hours per day (>0) to the outcomes of interest. The reported differences in outcomes are averages over the 1,314 subjects in the study and the percentages are ratios of risk for the outcome occurring in the group, rather than a prediction for each individual child.

    In other words, if you look at the whole study population grouped by hours of average daily TV viewing, those who watched 1 hour per day on average at age 2 1/2, when compared to those who watched 0 hours, consumed 9% more soft drinks and 10% more snacks, pursued 9% less physical activity and 13% less weekend sports, and had 5% higher body mass index, at age 10.They were 10% more likely to be victimized and had 6% lower math grades and 7% poorer classroom engagement. These relationships held for each additional hour.

    While I and many other parents would agree with that these differences are not modest, especially when they are due to an environmental factor in a young child’s life that we can control, this research quantifies the long-term developmental risk incurred when the short-term benefit of engaging the child with the television is chosen.

    Sincerely,
    Dr. Michael Rich
    http://www.askthemediatrician.org

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