Source Credibility: on the Independent Effects of Trust and Expertise

Abstract

Marketing researchers and practitioners have tended to assume that a more trustworthy source is more credible than a less trustworthy source. However, previous studies have either confounded trustworthiness with expertise and/or attractiveness, or found that trustworthiness did not influence persuasion. In the 2 x 3 between subjects factorial experiment three levels of source expertise were crossed by two levels of trustworthiness. Careful pretesting assured that the manipulations did not influence ratings of source attractiveness. The results supported the hypotheses developed from attribution theory that sources perceived to have external reasons for making a persuasive argument will be discounted. In addition, the results revealed that expert sources influenced perceptions of the product's qualities.