Moore, H. T. (1921). The Comparative Influence of Majority and Expert Opinion. American Journal of Psychology, 32, 16-20.
From PsychWiki - A Collaborative Psychology Wiki
No man or woman is an island and we are all influenced to various degrees by other individuals and groups. Moore was among the first psychologists to measure the degree of influence that individuals and groups have over others. Specifically, Moore examined the influence of majority and expert opinions in the realms of speech and pronunciation, ethical issues, and music. Participants made judgments about topics prior to receiving feedback and then following feedback about majority and expert opinions on the topics. Majority and expert opinions were considered influential when they caused decision reversals. Both majority and expert opinions were influential, however, each type of opinion’s level of influence varied across domains.