Metaphors for vaccination and defeasible reasoning

The project considers metaphor as a reasoning and a communicative device in health communication, to let people understand an abstract concept, vaccination, in terms of a concrete one, the beehive. The use of metaphors in vaccine communication might be crucial to let people understand vaccination as an important collective health phenomenon. We conducted a study to investigate whether and when a novel metaphor (“the beehive”), extended via the relevant property for vaccination (“cooperative”), can be an effective reasoning and communicative device. We proposed to participants three scenarios, described in both literal vs. metaphorical terms, comparing a safe scenario vs. a “free rider” scenario (undercutting defeater) and a “non-vaccinated community” scenario (rebutting defeater). Indeed, different premises in defeasible reasoning about vaccination could show that uncertain situations, depending on the proportion of unvaccinated people, could make a relevant difference for the conclusion on the need for being cooperative in vaccination. We hypothesized that metaphors could improve the communicative effects of pro-vaccination texts, especially in uncertain reasoning scenarios, in terms of persuasion, emotional impact, trust in experts/institutions, and vaccination intentions.