Motivating your teen

One psychologist suggests that the way to motivate your teen is Tough Love. I would just caution that this is clearly in the case of an overly-protected and coddled teen. Related findings (such as in Po Bronson's books) find that praising actions rather than labels ("working hard" as opposed to "being smart") creates more successful personalities. But the article is about what to do when it's getting to be too late.

on parenting teenagers

A new study finds that yelling at teenagers makes their behavior worse instead of better, says NPR. I don't have a teenager (yet), but I was one once. It was a terrifying and lonely experience. And I can confirm that my mother's attempt to berate me into being who she thought I should be only made me feel worse. I am sure the same is true of all relationships -- yelling at people makes them want to get away from you (and NOT to follow your loud and hostile instructions).