Abstract
Despite the societal impact of inter-group dishonesty, the specific circumstances and moral dispositions that influence this (immoral) behavior remain elusive. In this study, we examined the effect of different levels of shared Sense of Agency (s-SoA) with own team members and the type of moral dispositions on the tendency to deceive outgroups. To this end, we developed an online version of the Tone Tapping Task (TTT) to modulate s-SoA through partner predictability. Next, we run a within-subject experiment where 72 participants experienced a weak or strong s-SoA with their partner and then played the Multi-player Temptation to Lie Card Game, a moral task we devised to capture participants' decisions to lie to increase their team's monetary reward. Participants were presented with either favorable (own team win) or unfavorable (other team win) scenarios leading to low, medium, or high reward levels. Our analyses did not show a modulation of deceptive behavior based on the objective partner's predictability. However, we found that lower s-SoA ratings with the partner and lower group-oriented "binding" morality were associated with an increased frequency of outgroup-favouring lies for lower rewards. Furthermore, participants with higher scores in dispositional "binding" morality showed a positive correlation between s-SoA levels and the likelihood of committing ingroup-favoring lies. These results contribute to existing frameworks by integrating Moral Foundations Theory with research on shared sense of agency, highlighting how subjective experiences of coordination can enhance the effect of group-centered moral tendencies. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12144-025-08026-0.