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The Teenage Brain

Parents, teachers, and others who deal closely with teenagers know how difficult the adolescent (青少年的) years can be. This was thought to be due to the "foolishness of youth." Now, brain-imaging technology allows scientists to study the physical development of the brain in more details than ever before. Their discoveries have led a new theory of why teens act this way.

Recently, scientists have discovered that though our brains are almost at their full size by the age of six, they are far from fully developed. Only during adolescence do our brains truly "grow up." During this time, they go through great changes, like a computer system being upgraded. This "upgrade" was once thought to be finished by about age 12. Now scientists have found that our brains continue to change until age 25. Such changes make us better at balancing impulses (冲动) with following rules. But a still-developing brain does this clumsily (笨拙地). The result, scientists believe, is the unpredictable behavior seen in teenagers.

The studies show that teens are more likely to take risks. Luckily, the news isn't all bad. As brain scientist B. J. Casey points out, the teen brain inspires such behavior in order to help teens prepare for adult life.

One way the brain does this is by changing the way teens measure risk and reward (回报).

Researchers have found that when teens think about rewards, their brains release more of the chemicals that create pleasure. Researchers believe this makes the rewards seem more important than the risks, and makes teens feel the excitement of new experience.

Research into the structure of the teen brain have also found that it makes social connection seem especially rewarding. As such, teens have a strong need to meet new people. Because it is still developing, a teen brain can change to deal with new situations. So it connects social rewards with even more pleasure. In this way, the brain encourages teens to have a wide circle of friends, which is believed to make them more successful in life.

Unluckily, this need for greater rewards can sometimes lead teens to make bad decisions. However, it also means that teens are more likely, and less afraid, to try new things or to be independent. And in the long run, the impulses of the teen brain are what help teens leave their parents' care and live their own life successfully.

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