2026 Volume 33 Issue 3 Pages 546-563
In this paper, we define perceived social constraints as situations in which, during disagreements between humans and dialogue agents, individuals feel the need for consideration or consider adopting irrational opinions under structural constraints, such as maintaining future relationships with the speaker and social costs. Using video-based scenarios in which participants assumed the role of a moderator observing a discussion between a human and dialogue agent, we conducted three experiments. Experiment 1 (20 university students) showed that participants tended to adopt the human discussant’s incorrect opinion. Experiment 2 (234 crowdworkers) manipulated the agent’s modality (text, voice, robot) and replicated this pattern, again demonstrating that Perceived Social Constraints were particularly salient when the incorrect opinion was expressed by a human. No significant main effect of agent modality emerged, suggesting that Perceived Social Constraints are not tied to specific agent forms. Experiment 3 (144 crowdworkers) showed that the strength of interpersonal relationships can trigger irrational decision-making. These findings indicate that, even when dialogue agents possess high capabilities, interpersonal factors may hinder rational consensus formation in human–agent joint decision-making.
