Because I’m worth it! (more than others...): Cooperation, competition, and ownership bias in group decision-making

In group decision-making, people take insufficient account of the information coming from others. We hypothesize that this can be explained by an ownership bias that would especially occur in competition, rather than in cooperation. In a two-phase decision-making situation, people reached an initial decision and then evaluated the value of their own information and the consistent and inconsistent information of others under different conditions of goal interdependence (cooperation or competition). Finally, then had to reach a final decision regarding a road accident. Results showed an ownership bias in information value which is stronger in competition than in cooperation. Moreover, decision quality was lower in competition than in cooperation, an effect mediated by the ownership bias, beyond the preference effect.
Keywords: ownership bias, preference effect, information value, cooperation vs. competition, decision-making