Oath, autonomy and lying in groups

Previous studies have shown that an oath can reduce lying in individual settings. Can it reduce lying in groups, a context where the prevalence of lying is typically higher? Results from a lab experiment reveal that the impact depends on incentive structures and the extent of autonomy. A mandatory oath reduces lying when group members’ payoffs are independent, but only has a marginal effect when payoffs are dependent. Giving autonomy strengthens this impact under both incentive structures by fostering intrinsic motivation to keep promises. The findings highlight the importance of peer effects on the effectiveness of an oath.