Promises and Lies: An Experiment on Detecting Deception

Although economic and social relationships can involve deception (Gneezy 2005), such relationships are often governed by informal contracts that require trust (Berg et al. 1995). While important advances have been made concerning deception in economics, the research has focused little on written forms of communication. Are there certain systematic cues that signal written communications as dishonest? Are those signals accurately detected and used by message receivers? We fill this gap by studying messages written in a novel three-person trust game (we call it the “Mistress Game†). We find that: (i) messages that use encompassing terms, or a greater number of words, are significantly more likely to be viewed as promises; and (ii) promises that mention money are significantly more likely to be trusted. Notwithstanding the latter finding, we find senders who mention money within their promises to be significantly less likely to keep their word than those who do not. Length: 36