PsychSim: Agent-based modeling of social interactions and influence

Agent-based modeling of human social behavior is an increasingly important research area. For example, it is critical to designing virtual humans, human-like autonomous agents that interact with people in virtual worlds. A key factor in human social interaction is our beliefs about others, in particular a theory of mind. Whether we believe a message depends not only on its content but also on our model of the communicator. The actions we take are influenced by how we believe others will react. However, theory of mind is usually ignored in computational models of social interaction. In this paper, we present PsychSim, an implemented multiagent-based simulation tool for modeling interactions and influence among groups or individuals. Each agent has its own decision-theoretic model of the world, including beliefs about its environment and recursive models of other agents. Having thus given the agents a theory of mind, PsychSim also provides them with a psychologically motivated mechanism for updating their beliefs in response to actions and messages of other agents. We discuss PsychSim and present an example of its operation.