一位大学教授做过一个小小的实验。他从一群素不相识的人名中,随机挑选出一些人来,给他们寄去圣诞卡片。他估计可能会有一些回音,但随后发生的一切还是大大出乎他的意料。这些人回赠的节日卡片如雪花似的寄了回来,大部分给他回赠卡片的人根本就没想过打听一下这个陌生的教授到底是谁,他们收到卡片,自动就回赠了一张。这个实验规模虽小,却很巧妙地证明了人际互惠原则在人们的行为中所起的作用。由于互惠原则的影响 A university professor did a little experiment. From a group of strangers, he randomly selected some people and sent them Christmas cards. He estimates there may be some echoes, but everything that follows is far beyond his expectations. The holiday cards returned by these people, such as snowflakes, have been sent back. Most of the people who gave him a gift card did not even think about asking who the strange professor is. After receiving the card, they automatically donated one. The small scale of this experiment is a clever illustration of the role that the principle of reciprocity in human activity plays. Due to the principle of reciprocity