The effect of source credibility on the evaluation of statements in a spiritual and scientific context: A registered report study

The current registered report investigated the effects of source credibility in relation to one’s own worldviews (i.e. supernatural beliefs and belief in science) in a spiritual and scientific context. We asked people to rate the truthfulness of ambiguous auditory statements about the cosmos attributed to a scientist or a spiritual guru and analyzed this using hierarchical Bayesian modeling. In line with our hypotheses, we found that the scientist was seen as more credible than the spiritual guru. The overall credibility of the statements was positively related to supernatural beliefs. These beliefs also interacted with the source of the statement, which was reflected in a tendency for supernatural believers to rate statements from both the scientist and the guru as credible. In contrast, with increasing belief in science, the credibility of the sources diverged with higher ratings for the scientist compared to the guru. The study involved a conceptual replication of previous research and increased the confidence in the robustness of source credibility effects and their interaction with people’s worldviews.