二战期间,美国心理学家在招募的一批行为不良、纪律散漫、不听指挥的新士兵中做了如下试验:让他们每人每月向家人写一封信,要说自己在前线如何遵守纪律、听从指挥、奋勇杀敌、立功受奖等内容。结果,半年后这些士兵发生了很大的变化,他们真的像信上所说的那样去努力了。这种现象 During the Second World War, American psychologists conducted a series of tests on recruiting a group of new soldiers who were delinquent, undisciplined, and did not listen to the command: let them each write a letter to their families every month to say how they are obeying the front line. Discipline, follow the command, bravely defeat the enemy, meritorious service, etc. As a result, these soldiers have undergone great changes after six months. They really did as they said. this phenomenon