The strength of a message can affect whether or not an individual tells the truth; Stronger messages are found to increase truth-telling by 30 percentage points

Language and Lies. Glynis Gawn, Robert Innes. Journal of Behavioral and Experimental Economics, https://doi.org/10.1016/j.socec.2018.04.007

Highlights
•    The strength of a message can affect whether or not an individual tells the truth.
•    An experiment measures how message type affects a sender’s intrinsic lie aversion.
•    “Strong” vs. “weak” messages significantly promote truthfulness in the experiment.
•    Stronger messages are found to increase truth-telling by 30 percentage points.
•    Differential aversion to “weak” vs. “strong” lies can be socially advantageous.

Abstract: Does an individual’s aversion to a lie depend upon the language used to communicate the lie? We adapt the Lopez-Perez and Spiegelman (2013) dot experiment to measure how a “weak” vs. “strong” message affects individuals’ propensities for truthfulness when there is a monetary incentive to lie and no other person is affected by the communication. Weak messages state a fact, whereas strong statements “solemnly swear” to the fact. In our first (between-subject) experiment, strong (vs. weak) statements increase the percentage of subjects choosing to tell the truth by approximately 30 percentage points in each of three different payoff scenarios that favor lying to a different extent. Because lies increase payoffs in the experiment, the weaker aversion to weaker lies is socially advantageous. In a second (within-subject) experiment participants choose between messages of different strength and we find (1) a preference for lying with weak (vs. strong) language, and (2) a significant fraction of subjects who are willing to pay a positive amount to avoid a strong vs. weak lie. From both experiments, we conclude that our subjects tend to be intrinsically less averse to dishonesty when a lie is conveyed with weak vs. strong language.

Keywords: Deception; Language; Communication; Lying Aversion