Good To Know: TV, Exercise, Correlation, Causality

MINNEAPOLIS (WCCO) -- A new study that looks into "screen time" in teenagers has found some disturbing trends among kids who spend their free time in front of a TV or computer. Don Shelby says, the research scares those who thought physical activity offset the damage.

The study, published in Pediatrics magazine, says what we thought we already knew. Young people who watch two hours of TV a day, or surf the internet or play games online for the same amount of time, are way more likely to have real psychological difficulties later on.

In previous studies, researchers found that vigorous activity offset those problems. This research found half of even physically-active children who faced a lot of screens showed negative psychological tendencies.

Now, here's the hard part of the science. The researchers can't say whether the screens are causing the problem, or the kids with problems are more apt to be in front of a screen. TVs and computers, therefore, may not be the culprit, but a symptom of the problem.

The take-away for parents, if the kid is holed up with the computer or glued to the TV, the red flags should go up.