Field dependence and attitude change: Source credibility can alter persuasion by affecting message‐relevant thinking

Abstract The present study shows that for a personally relevant counterattitudinal issue, a highly credible source can alter persuasibility by increasing a subject's message‐relevant thinking. Previous failures to show this effect were probably due to the highly thoughtful nature of typical research subjects, when confronted with involving issues. In the present study, field‐dependent and field‐independent subjects heard convincing or refutable counterattitudinal speeches given by sources of high or low credibility. Results indicated that subjects who are typically low in differentiation of stimuli (field‐dependent subjects) showed differential persuasion to strong and weak arguments only when they were presented by a highly credible source. For subjects who are typically high in propensity to differentiate stimuli (field‐independent subjects), the arguments were differentially persuasive for both high and low credible sources. These results are consistent with the hypothesis that increasing source credibility can enhance message‐relevant thought for subjects who typically do not scrutinize message content.