An honesty oath leads to more truth telling; liars need more time to decide under oath

How the honesty oath works: Quick, intuitive truth telling under oath. Tobias Beck. Journal of Behavioral and Experimental Economics, May 29 2021, 101728. https://doi.org/10.1016/j.socec.2021.101728

Highlights

• An honesty oath leads to more truth telling

• The additional truth tellers under oath decide very fast

• Liars need more time to decide under oath

• The oath reduces the extent of strategic reasoning in the decision whether to tell the truth or not

• The honesty oath works by making the decision to tell the truth more intuitive and less deliberate

Abstract: This study analyzes the workings of oath-taking when the decision about lying requires strategic thinking. In a laboratory experiment, the oath leads to more truth telling, but it does not make liars reduce the sizes of their lies. While truth tellers decide faster due to the oath, liars need more time to decide under oath. By analyzing players’ beliefs about their co-players’ mistrust, I find that the oath reduces the extent of strategic reasoning in the decision whether to tell the truth or not. These findings are consistent with the conjecture that the honesty oath works by making the decision to tell the truth less deliberate and more intuitive.

Keywords: Honesty oathStrategic deceptionTruth tellingSize of the lieLaboratory experiment