Deception Detection Research: Some Lessons for the Epistemology of Testimony

According to our folk theory, we can reliably detect when people are lying through observing behavioral cues. The cues occur because people are motivated to lie but afraid to get caught. Lying is also commonplace according to our folk theory, so it is a good thing that we have this capacity to tell when people are deceiving. Social epistemologists have agreed, elevating our folk theory into epistemological wisdom. Elizabeth Fricker's epistemology of testimony leads the field in transforming folk thoughts into philosophical theories. Extensive research in communication studies, however, shows that our folk theory is mistaken. The social epistemology of communication should understand and incorporate lessons from this research when explaining why we acquire knowledge and justification through conversation and when making recommendations for how to do better. Starting with the facts provides a surer foundation. This chapter elaborates this research, with special attention to its ecological validity, concluding with a detailed discussion of Fricker's argument for a monitoring requirement on justified testimony-based belief and her argument that we frequently possess a reliably true quasi-perceptual belief that our speakers are trustworthy.