A Rational-Pragmatic Account of Communicative Demonstrations

Abstract

Theory of mind enables an observer to interpret others’ behavior in terms of unobservable beliefs, desires, intentions, feelings, and expectations about the world. This also empowers the person whose behavior is being observed: By intelligently modifying her actions, she can influence the mental representations that an observer ascribes to her, and by extension, what the observer comes to believe about the world. That is, she can engage in intentionally communicative demonstrations. Here, we develop a computational account of generating and interpreting communicative demonstrations by explicitly distinguishing between two interacting types of intentions. Object-directed intentions aim to control states of the physical environment, whereas belief-directed intentions aim to influence an observer’s mental representations. This formulation provides a number of theoretical insights. In particular, our framework (1) extends existing formal models of pragmatics and pedagogy to the setting of value-guided decision-making, (2) captures how people modify their intentional behavior to show what they know about the reward or causal structure of an environment, and (3) helps explain data on infant and child imitation in terms of differential attribution to adult demonstrators’ object-directed and belief-directed intentions. Additionally, our analysis of belief-directed intentionality and mentalizing helps shed light on the socio-cognitive mechanisms that underlie distinctly human forms of communication, culture, and sociality.