Limits of Credibility: The Case of Political Persuasion

The present study explores the interactive effects of three major variables affecting message acceptance: source credibility, recipients' involvement, and locus of control. Statements representing a political party's views on the causes of a negative economic situation were evaluated by 381 Canadian students for degree of acceptance. They also evaluated the party's credibility and assessed their personal involvement in the economic situation. Contrary to the predictions of the Petty and Cacioppo (1979) Elaboration Likelihood Model (ELM), the results show that credibility had an impact on message acceptance in situations of both low and high involvement, but high involvement enhanced message acceptance, confirming ELM and contradicting Sherifs social judgment theory. Externally controlled recipients proved to be more sensitive to the effects of credibility.