SSS 2010-05-03（在线收听）

This is Scientific American's Sixty-Second Psych. I'm Christie Nicholson. Got the minute?

Say a teenager takes the car without permission and crashes it. Or pole jumps off a bridge into white water. Bruised, broken or worse, arrested, the first words out of a parent's mouth are: What were you thinking?

And the inevitable response from the teen: I don't know. Nothing. I wasn't thinking of anything!

Prior studies have suggested that increased risk-taking in teenagers has to do with the late development of executive functions in the brain that control impulsivity.

But research out of the Annenberg Public Policy Center and the Children's Hospital of Philadelphia shows it might not always be about a delay in cognitive function. For four years they tracked the risky moves and executive brain function (here they tested for working memory as one indicator of impulsivity control) of almost 400 youths of mixed race and backgrounds.

The researchers found that different kinds of impulsivity correlated with working memory. Sure, those who "acted without thinking" did tend to have poor working memory. But there was another group, who tended toward sensation-seeking behavior, who appear to have more awareness of what they're doing. This group had significantly more developed working memory.

The researchers note that many adolescents do have the capacity to control their risk-taking, and we will need to find ways for them to channel sensation-seeking drives toward safer activities. Like staying in regulated skateboard parks instead of trying to latch their skateboard to a car on the Brooklyn-Queens Expressway.

—Christie Nicholson