Truth Bias

Abstract

We conduct experiments of a cheap-talk game with incomplete information in which one sender type has an incentive to misrepresent her type. Although that Sender type mostly lies in the experiments, the Receiver tends to believe the Sender’s messages. This confirms “truth bias” reported in communication theory in a one-shot, anonymous environment without nonverbal cues. These results cannot be explained by existing refinement theories, while a bounded rationality model explains them under certain conditions. We claim that the theory for the evolution of language should address why truthful communication survives in the environment in which lying succeeds.

1 Introduction

Verbal communication can occur even between senders and receivers with conflicting interests, and is often accompanied by lying and suspicion. Some communication-theoretic literature reports that, even in such situations, although senders usually lie, most receivers believe senders’ messages; this is called “truth bias,” the receiver’s intrinsic presumption that the senders are telling the truth (McCornack and Parks, 1986). The purpose of this paper is to...