跳蚤实验———心理学家将一只跳蚤放进没有盖子的杯子内，结果跳蚤轻而易举地跳出了杯子。紧接着，心理学家用一块玻璃盖住杯子，于是，跳蚤每次往上跳时，都因撞到这块玻璃而跳不出去。过了一些时候，心理学家把这块玻璃拿掉，结果跳蚤再也不愿意跳了，自然也就没有跳出杯子 Flea experiment --- Psychologists will be a flea into a cup without a lid, the results fleas easily out of the cup. Then, the psychologist covered the glass with a piece of glass, so every time the flea jumped up, it hit the glass and could not jump out. After some time, the psychologist took the piece of glass off, and the result was that the flea was not willing to jump any longer and naturally did not jump out of the cup