Highly Credible Sources: Persuasive Facilitators or Persuasive Liabilities

A low credibility source induced a more positive attitude toward his ad-vocacy than did a highly credible source when message recipients ' own behavior served as a cue for determining their attitudes. In contrast, when the behavioral cue was absent, a highly credible source did not have an adverse effect on individuals ' attitudes or behavior. These findings are interpreted in terms of self-perception theory and cognitive response analysis. Communication practitioners appear to share the belief that a communicator's attributes of character have a significant impact on the persuasiveness of an appeal. Thus, advertisers select consumers who typify the target audience to provide testimonials, manufac-turers seek seals of approval from independent testing agencies, and politicians marshal the support of nationally prominent dignitaries to endorse their platforms. Support for this premise derives from experimental research dealing with the persuasive effect of source credibility. Characteristic of this research is the determination of the attitude change induced by systematic manipulation of one or more of the dimensions of credibility-trustworthiness, expertise, and attractiveness. Using this paradigm it has been found that highly trustworthy and/or expert sources induce more immediate attitude change than do sources having less of these attributes (Hovland and Weiss