Visualizing pathogens: Disfluent shapes of pathogens increase their perceived complexity and danger while realism and disfluency boost the credibility of visualizations.

During the COVID-19 pandemic, the public was regularly presented with visualizations of the viral pathogen causing this disease. Since there are several ways of visually communicating information, we investigate whether different types of visualizations affect how viewers judge the credibility of information as well as the complexity and potential harm of pathogens. A first experiment was conducted to assess whether a round, fluent shape elicits a different response than pathogens featuring disfluent components such as thread-like appendages. Visualizations of disfluent bacteria were rated as more credible than those of fluent bacteria. In Experiment 2, bacteria were either presented as realistic renderings or as cartoon-like line drawings (varied between-subjects). Furthermore, half of the six bacteria had fluent shapes, while the other half featured disfluent shapes, resulting in the within-subjects factor of fluency. Participants were asked to rate the credibility, complexity, and risk of serious illness associated with these bacteria. We found that disfluent bacteria were perceived as having a more complex metabolism and as holding a higher risk for serious illness. Furthermore, realism and disfluent shapes increase the credibility of visualizations, but not the credibility of additional information. These results have important implications for the field of science communication.