A formal analysis of trust and distrust relationships in Shakespeare’s Othello

In settings where agents can be exploited, trust and reputation are key issues. As a consequence, within the multi-agent systems community, considerable research has gone into the development of computationally viable models of these concepts. In this paper, we present an abstract framework that allows agents to form coalitions with agents that they believe to be trustworthy. In contrast to many other models, we take the notion of distrust to be our key social concept. We use a graph theoretic model to capture the distrust relations within a society, and use this model to formulate several notions of mutually trusting coalitions. We investigate principled techniques for how the information present in our distrust model can be aggregated to produce individual measures of how trustworthy an agent is considered to be by a society. We extend the framework with trust relationships and introduce the notion of Trust-Coalitions (T-Coalitions). We finally provide an analysis of the Shakespeare’s tragedy, Othello, using our abstract framework.