The Ultimatum Game as Measurement Tool for Anthropomorphism in Human-Robot Interaction

Anthropomorphism is the tendency to attribute human characteristics to non-human entities. This paper presents exploratory work to evaluate how human responses during the ultimatum game vary according to the level of anthropomorphism of the opponent, which was either a human, a humanoid robot or a computer. Results from an on-line user study (N=138) show that rejection scores are higher in the case of a computer opponent than in the case of a human or robotic opponent. Participants also took significantly longer to reply to the offer of the computer rather than to the robot. This indicates that players might use similar ways to decide whether to accept or reject offers made by robotic or human opponents which are different in the case of a computer opponent.