Students with a TV in the bedroom score lower on standardized tests; those with a home computer score higher. OK, not a shock, but the differences are significant. Stanford and Johns Hopkins researchers found an 8 to 10 percent decline in scores for third graders with their own TV; computer users scored 7 to 9 percent higher.
Researchers speculate that parents who give their child computer access value educational achievement more than parents who provide a personal TV. But in the California study, 71 percent of children had their own TV.
A Seattle study found TV watching before the age of three correlates with lower test scores when children reach school age. However, older children learn from educational TV programs, the study concluded.
A New Zealand study, controlled for IQ, socioeconomic status and early childhood behavior problems, found heavy TV watchers were more likely to leave school without a diploma.
My guess is that kids who watch a lot of TV necessarily watch a lot of junk and have less time for active playing.