An article from USA Today points out findings of various studies that demonstrate teens do better when they have parents who set and enforce boundaries.

Here's some good news for parents of tweens and teens: You rule.

That may be hard to believe sometimes. And it's true kids won't always follow your health and safety rules. But studies show parents who keep setting boundaries make a huge difference. In other words, "parenting works," even for teens, says Alanna Levine, a pediatrician in Tappan, N.Y., and spokeswoman for the American Academy of Pediatrics.

The latest example: a survey on media use by the Kaiser Family Foundation. It found that typical kids ages 8 to 18 spend an astounding 7 hours and 38 minutes a day consuming entertainment media, drinking deeply from the fire hose of TV, computers, game consoles, cellphones, music players and other devices (while occasionally glancing at books and other non-electronic media). Many experts, including the pediatrics academy, consider that much screen time bad for mental and physical health.

But the study also found that kids whose parents set any time or content limits were plugged in for three hours less each day. "Parents can have a big influence," says Kaiser researcher Vicky Rideout.

And it doesn't stop with screen time...

p>Source: USA Today
http://www.usatoday.com/news/health/painter/2010-02-08-yourhealth08_ST_N.htm