Teenagers are a puzzle, and not just to their parents. When kids pass from childhood to adolescence their mortality rate doubles, despite the fact that teenagers are stronger and faster than children as well as more resistant to disease. Parents and scientists alike abound with explanations. It is tempting to put it down to plain stupidity: Teenagers have not yet learned how to make good choices. But that is simply not true. Psychologists have found that teenagers are about as adept as adults at recognizing the risks of dangerous behavior. Something else is at work.
Scientists are finally figuring out what that “something” is. Our brains have networks of neurons that weigh the costs and benefits of potential actions. Together these networks calculate how valuable things are and how far we’ll go to get them, making judgments in hundredths of a second, far from our conscious awareness. Recent research reveals that teen brains go awry because they weigh those consequences in peculiar ways.