Knowing the truth or telling it? An exploratory study about the relationship between source credibility and behavioral intention in a counter-attitudinal communication

Since the time of Aristotle, perceived source credibility has been presumed as a fundamental pillar in the construction of persuasive communication. With the advent of the modern science of persuasion, data has supported this common idea. But, if the results seem almost crystal clear at a surface level, when it comes to unravel the core dimensions of source credibility, the picture becomes blurry. Following the path traced by the Yale school, in fact, source credibility is not a monolithic construct but rather a bidimensional one, consisting in the evaluation of the source’s expertise and trustworthiness. These dimensions seem to have differential weights, but the results are somewhat mixed, making it difficult to evaluate if both are necessary in persuasive communication. Starting from this theoretical but also practical question, we conducted a study with the aim of exploring if the source’s perceived expertise, trustworthiness, or both, could predict the behavioral intention of respondents to buy a product that is almost blasphemy for Italians, namely Hawaiian pizza. We chose this specific product because we were reasonably confident that our participants would dislike Hawaiian pizza and, consequently, that we had the opportunity to test factors which could lead to response changing (i.e., a negative response becomes positive or vice versa). We recruited 261 Italian participants; furthermore, we selected the subsample that indicated low liking of Hawaiian pizza (n = 210). After conducting a proportional odds logistic regression, results revealed a significant effect only for expertise (neither for trustworthiness nor for the expertise by trustworthiness interaction) and further regression analyses gave support to the relevance of the source’s perceived competence. These results, although counterintuitive, fit well with recent findings from the application of the Theory of Reasoned Action, leaving space to a discussion of the practical and theoretical implications of the relevance of expertise.