Effects of Competing Statistical and Testimonial Evidence in Debates About Science

Communication technologies have expanded the range of actors who participate in public debates about science. When experts communicate with the public, scientifically-derived statistical evidence competes with the testimony of non-experts. This study investigates how competing statistical and testimonial evidence affect attitudes toward an issue and the debating speakers. Our findings suggest an advantage to asserting statistical evidence in competitive debates about science; a dissenting lay person is considered more credible when asserting statistical evidence in response to an expert’s testimony than when they assert testimonial evidence. Additionally, prior support for the issue affects evaluations of speakers and issue attitudes.