Authors' academic but not personal expertise or gender affect message credibility in science communication.

Evaluating message credibility is critical for understanding scientific information and informed decision making. People's ability to assess the credibility of science communication texts is influenced by several factors. In three experiments, we examined the impact of authors' gender as well as different types of expertise on readers' credibility perceptions. In Experiment 1 (n = 203), we varied authors' alleged gender and expertise. We found that a text allegedly written by a high-expertise author was rated as more credible than the same text by a low-expertise author. There was no effect of authors' gender. Experiment 2 (n = 182) was a replication of the first study with a different sample. We did not find any effects of gender or expertise on perceived message credibility. In Experiment 3 (n = 206), we differentiated between academic and personal expertise and manipulated these types of expertise independently. The data indicated that academic expertise was a significant positive predictor of perceived message credibility, while personal expertise was not. We discuss these findings in terms of their significance for the trustworthiness of science communication and examine the relevance of differentiating the concept of expertise in this context.