Americans between the ages of 8 and 18 devote an average of 7 hours, 38 minutes a day — or 53 hours a week — to media use, according to a report by the Kaiser Family Foundation. That is up by more than an hour from five years ago, when a similar study was conducted. The study also noted a link between heavy media users and lower grades, showing that 47% of the heaviest users earned C’s or lower, while 23% of light users earned the same grades. Researchers could not say if there was a cause-and-effect link between heavy media use and grades.

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