How much television children watch-and what they watch-makes a difference in school

The more weekday time that middle-school children devote to television, movies, and video games, the more likely they are to do poorly in school, a recent study has shown. Exposure to cable-TV movie channels and R-rated movies also has a detrimental effect on school work.

Investigators conducted a cross-sectional survey of approximately 4,500 adolescents from 15 New England middle schools (grades five through eight). Median age was 12 years; the number of boys and girls was about equal. Most participants were white, and their parents were high-school graduates. Participants were asked to describe their grades the preceding year (excellent, good, average, or below average) and how much time they spent with visual media on weekdays and on weekends. Researchers also determined, for each participant, cable-TV movie channel availability and their parents' restrictions on TV content and R-rated movies.

To distinguish the effects of media exposure from other variables, investigators also assessed each participant's personality (using standard indices of self-esteem, rebelliousness, and sensation seeking), his (or her) mother's parenting style (using a questionnaire), and demographics.

Cable-TV movie channel availability also increased the likelihood of poorer school performance. Similarly, children who watched R-rated movies were more likely to report poor school performance than children whose parents never allowed them to watch such movies. Restrictions on what parents allowed children to watch had a far greater effect on school performance than other influences, including parenting style and the child's level of self-esteem or rebelliousness (Sharif I et al: Pediatrics 2006;118:e1061).

Commentary In this carefully planned study, investigators found support for both "displacement" and "content" hypotheses. Time spent on TV and video games displaces schoolwork, reading, and other, more constructive activities. But what is viewed-content-also seems to have an influence on school performance.

Parents need to hear about these findings and other evidence about the impact of media on their children. They should also know about the recommendations of the American Academy of Pediatrics on limiting exposure to media (available at http://www.aap.org/ in the Children's Health Topics section).