美国科学60秒 SSS 2013-02-14（在线收听）

 　　School are well known reservoir of contagion, where students share all sorts of communicable conditions, coughs, cold, flu, you name it. But gems are the only things kids can catch from their friends. If they are lucky, they could come down with 4.0. Because a new study shows that high schoolers whose friends get higher marks tend to raise their own grade averages over time. The findings are in the journal Plus 1. That our social circles influence us is not news. For example, studies have shown that the fatter your friends, the more likely you are also overweight. In the grade point study, researchers took the classroom to see whether academic achievement might as contagious as obesity. They asked 158 eleven graders to go down the class roster and point out their pals. And they checked everyone's report card, at the time of survey and again a year later. The researchers found that those students whose friends were outshining academically, tend to improve their grades over the year. While those who were hanging out with academic under-achievers, let their grades slid. So go ahead, be friend with brainier. You might just learn something.