Better think before agreeing twice. Mere agreement: a similarity-based persuasion mechanism

The present paper shows that the frequency of people's compliance with a request can be substantially increased if the requester first gets them to agree with a series of statements unrelated to the request but selected to induce agreement. We label this effect the ‘mere-agreement effect’ and present a two-step similarity-based mechanism to explain it. Across five studies, we show that induced mere agreement subtly causes respondents to view the presenter of the statements as similar to themselves, which in turn increases the frequency compliance with a request from that same person. We support the similarity explanation by showing that the effect of agreement on compliance is suppressed when agreement is induced to indicate dissimilarity with the interviewer, when the request is made by some other person, and when the artificially high level of agreement is made salient. We also validate the practical relevance of the mere-agreement persuasion technique in a field study. We discuss how the mere-agreement effect can be broadly used as a tool to increase cooperation and be readily implemented in marketing interactions.