Proceedings of the Annual Meeting of the Cognitive Science Society

This study investigates the formation of reciprocal altruism in human-agent interactions using the ultimatum game, focusing on how people infer others' action-generation principles. We examine the effects of different agent strategies on human rejection behavior and agent impression. An experiment is conducted where two factors are manipulated in the agent's strategy: the presence of a selfish, egocentric strategy based on the agent's internal policy; and an altruistic, exocentric strategy that adjusts to the participant's feedback. The results show that participants rejected proposals less frequently when the agent adopted exocentric/non-egocentric strategies. Furthermore, the exocentric strategy increased the perception of safety toward the agent, whereas the egocentric strategy decreased the perception of intelligence. These findings suggest that cooperative behavior and social impressions are shaped not only by outcome distributions but also by inferences about latent policy parameters, such as responsiveness to social signals and rigidity of internal dynamics.