Effects of observed counterfactual on prosocial lying: A preliminary report

  • Ryo Oda Nagoya Institute of Technology
  • Motoki Kato Nagoya Institute of Technology
  • Kai Hiraishi Keio University
Keywords: prosocial lie counterfactual justification lying morality


Prosocial lie is an interesting subject in evolutionary psychology because generosity toward others is sometimes inconsistent with adherence to norms. People use justification to tell a lie without threatening the positive self-concept. Previous studies have demonstrated that observing desired counterfactuals encourages justified lying. For example, in the ‘die-under-the-cup’ experimental paradigm, where no one except the participant knew the number of a rolled die, participants who rolled the die once lied less than those who rolled multiple times. This suggests that participants in the multiple-roll condition reported the highest value they observed on all rolls. However, the effects of counterfactuals were only assessed indirectly. In this study, the number that was actually rolled in the ‘die-under-the-cup’ paradigm was determined using a mechanical die. Participants were given an incentive of a donation to charity. Only seven of 133 participants (5.2%) were prosocial liars (i.e., reported a larger number than their actual first roll). Six of the seven liars were female. Honesty decreased when the first roll was a lower number (1, 2 or 3). Not all prosocial liars reported the largest number they had rolled.    
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