Re-visting the Ultimatum Game: Understanding Responses to Robotic Opponents

Robots rarely (if ever) consider properties of fairness in their decision-making despite tangible research in adjacent fields. In psychology and human-computer interaction, the ultimatum game has been used to examine how people respond to perceptions of fairness and unfairness when making decisions by splitting a hypothetical pot of money. In the current study, it is used to examine how human decision-makers interact with intelligent agents, in an effort to see whether human opponents are treated the same or differently compared to artificial opponents. We conducted a mixed-design online study where participants played the Ultimatum game against three different opponents: humans, a random number generator, and one of two embodiments of an intelligent agent. The results of the N=108 participant study indicated that the embodiment of an intelligent agent has no effect on human responses to the Ultimatum game and suggests intelligent computer systems may be treated the same as humans.