Commitment to honesty oaths decreases dishonesty, but commitment to another individual does not affect dishonesty.

Social commitment influences our behavior in various ways. Recent studies suggest that social commitment to other individuals or groups can increase dishonest behavior while feeling commitment to moral norms might decrease it. Here we show in a pre-registered series of 7 studies investigating the influence of social commitment on dishonest behavior by sampling 7566 participants across three countries (the UK, the US, and Mexico) that commitment to moral norms via honesty oaths might decrease dishonesty (OR = 0.79 [0.72, 0.88]). To the contrary, we found no credible evidence that social commitment to other individuals increases dishonesty (OR = 1.08 [0.97, 1.20]). Finally, we observed that commitment to moral norms was less effective if participants were committed to another individual at the same time (OR = 0.95 [0.86, 1.06]). Our findings point at the potential effectiveness of honesty oaths, while the observed effect sizes were small compared to previous studies.