Public Scientific Testimony I

Abstract Chapter 5 concerns scientific expert testimony—i.e., testimony from scientific experts to laypersons. It surveys empirical research on social and psychological challenges for the public’s uptake of public scientific testimony. On this basis, it articulates a novel norm for scientific expert testifiers: Justification Expert Testimony (JET). According to JET, scientific expert testifiers should, whenever feasible, include appropriate aspects of the nature and strength of the relevant scientific justification, or lack thereof, in their testimony. JET is deployed in motivating a guideline concerning scientific expert trespassing testimony, which occurs when a scientific expert testifies on matters in a domain of epistemic expertise other than her own. According to this Expert Trespassing Guideline, a scientific expert who provides expert trespassing testimony should, in some contexts, qualify her testimony to indicate that it does not amount to expert testimony. So, Chapter 5 exemplifies the gradual movement from foundational research to applied research.