Abstract
This paper proposes a method for an artificial agent to behave socially by controlling it by active inference with an empathy mechanism. Active inference is a Bayesian hypothesis for understanding the mechanism of a biological agent’s cognitive activities and is basically defined for single-agent cases. We extended active inference to the case of an agent surrounded by other agents. These other agents are not only objects of recognition but also sources of social perceptions and actions. An agent controlled with the proposed method infers the others’ expectations toward itself on the basis of an empathy mechanism and tries to act in response to the expectations. Although defining proper sociality for a given situation is difficult since it differs by situation, we define sociality as an agent behaving as others expect. Accordingly, the others surrounding the agent are teachers for the agent to learn proper sociality; thus, an agent controlled with the proposed method can learn proper sociality in a variety of situations in a unified manner. We evaluated the proposed method regarding the controlling of autonomous mobile robots (AMRs) and evaluated sociality from the trajectory of the AMRs. From the evaluation results, an agent controlled with the proposed method could behave more socially than an agent controlled by standard active inference. In two agents case, the agent controlled with the proposed method behaved in a social way that decreased travel distance of another by 13.7% and increased margin between the agents by 25.8%, even if it increased travel distance of the agent by 8.2%. They also indicate that an agent controlled with the proposed method behaves more socially when it is surrounded by altruistic others but less socially when surrounded by selfish others.