Communicator credibility and initial attitude as variables in persuasion

Abstract

Abstract : Using a 2x3 factorial design in which two levels of source credibility were combined with three levels of initial attitude, 144 experimental subjects and 78 control subjects were exposed to tape-recorded arguments advocating withdrawal of United States military forces from Vietnam. Dissonance theory predicts an interaction between initial attitude and source credibility in determining attitude change. The results of the experiment revealed that only the highly credible source effectively induced attitude change in the subjects, and that such change was independent of the subjects' initial attitudes. Derogation of both the source and the communication was a direct function of extent of discrepancy between the position advocated and the initial disposition of the subjects. The predictions from dissonance theory were not supported, but the importance of source credibility as a major variable in persuasion was confirmed. (Author)