How The Neural And Psychological Systems Have Changed Adolescence

The crucial new idea is that there are two different neural and psychological systems that interact to turn children into adults. Over the past two centuries, and even more over the past generation, the developmental timing of these two systems has changed. That, in turn, has profoundly changed adolescence and produced new kinds of adolescent woe. The big question for anyone who deals with young people today is how we can go about bringing these cogs of the teenage mind into sync once again. The first of these systems has to do with emotion and motivation. It is very closely linked to the biological and chemical changes of puberty and involves the areas of the brain that respond to rewards. This is the system that turns placid 10-year-olds into restless, exuberant, emotionally intense

The reward centers of the adolescent brain are much more active than those of either children or adults. Think about the incomparable intensity of first love, the never-to-be-recaptured glory of the high-school basketball championship. What teenagers want most of all are social rewards, especially the respect of their peers. In a recent study by the developmental psychologist Laurence Steinberg at Temple University, teenagers did a simulated high-risk driving task while they were lying in an fMRI brain-imaging machine. The reward system of their brains lighted up much more when they thought another teenager was watching what they did—and they took more risks. From an evolutionary point of view, this all makes perfect sense. One of the most distinctive evolutionary features of human beings is our unusually long, protected childhood. Human children depend on adults for much longer than those of any other primate. That long protected period also allows us to learn much more than any other animal. But eventually, we have to leave the safe