Explaining Sympathetic Actions of Rational Agents

Typically, humans do not act purely rationally in the sense of classic economic theory. Different patterns of human actions have been identified that are not aligned with the traditional view of human actors as rational agents that act to maximize their own utility function. For instance, humans often act sympathetically – i.e., they choose actions that serve others in disregard of their egoistic preferences. Even if there is no immediate benefit resulting from a sympathetic action, it can be beneficial for the executing individual in the long run. This paper builds upon the premise that it can be beneficial to design autonomous agents that employ sympathetic actions in a similar manner as humans do. We create a taxonomy of sympathetic actions, that reflects different goal types an agent can have to act sympathetically. To ensure that the sympathetic actions are recognized as such, we propose different explanation approaches autonomous agents may use. In this context, we focus on human-agent interaction scenarios. As a first step towards an empirical evaluation, we conduct a preliminary human-robot interaction study that investigates the effect of explanations of (somewhat) sympathetic robot actions on the human participants of human-robot ultimatum games. While the study does not provide statistically significant findings (but notable differences), it can inform future in-depth empirical evaluations.