社会心理学家弗里德曼与弗雷瑟曾做过一个实验。他们到两个居民区劝说人们在房前竖一块写有“小心驾驶”的大标语牌。在第一个居民区直接提出要求,遭到大多数人的拒绝。在第二个居民区,他们先请求居民在一份赞成安全行驶的请愿书上签字,所有被要求者照办。几周后, Social psychologist Friedman and Freusen have done an experiment. They went to two neighborhoods to persuade people to put up a large placard in front of their house with “CARE DRIVE”. In the first residential area directly requested, was rejected by the majority. In the second neighborhood, they first asked their residents to sign a petition in favor of safe driving and all those required to do so were signed. A few weeks later,