The evolution of testimony: Receiver vigilance, speaker honesty and the reliability of communication

Drawing on both empirical evidence and evolutionary considerations, Sperber et al. argue that humans have a suite of evolved mechanisms for ‘epistemic vigilance’. On their view, vigilance plays a crucial role in ensuring the reliability and hence the evolutionary stability of communication. This article responds to their argument for vigilance, drawing on additional empirical evidence (from deception detection research) and evolutionary considerations (from animal signalling research) to defend a more optimistic, quasi-Reidian view of communication. On this alternative view, the lion’s share of the responsibility for explaining the reliability of testimony falls not to the vigilance of receivers but rather to the honesty of communicators, implying that vigilance does not play a major role in explaining the evolutionary stability of communication.