心理学家做过这样一个试验：将一只饥饿的鳄鱼和一些小鱼放在水族箱的两端，中间用透明的玻璃板隔开。刚开始鳄鱼毫不犹豫地向小鱼发动进攻，它失败了，但毫不气馁；接着，它又向小鱼发动了第二次更猛烈的攻击，它又失败了，并且受了重伤；它还要攻击，第三次、第四次……多次 Psychologists have done such a test: a hungry crocodile and some fish on both ends of the aquarium, separated by a transparent glass plate. At first, the crocodile attacked the little fish without hesitation. It failed but was not discouraged. Then it launched another, more violent attack on the fish, which again failed and was seriously wounded; it Also attack, the third, the fourth ... ... many times