Explaining joint attention: Between epistemic justification and psychological processing

The ability to engage in joint attention, where two individuals attend to the same object or event together, provides an evidential basis for coordinated behaviours and interactions. To play this role, joint attention is often defined as a mutually open, or transparent relation between co-attenders. But how should this openness be characterised? Two broad theoretical views have been proposed. One view reductively accounts for the openness of joint attention in terms of individual mental states and properties. In contrast, according to non-reductive views, openness is based on some primitive intersubjective relation, irreducible to the individual states of each co-attender. I argue that tensions in these approaches arise from the methodological attempt to address normative and cognitive explananda simultaneously. Both approaches are primarily designed to tackle the normative epistemological concerns of joint attention, and their explanatory limitations arise when they conflate these concerns with psychological ones. I outline the case for a probabilistic account of joint attention based on a weaker notion of mutual awareness, and then assess its epistemic implications. The upshot is that the emphasis on a normatively justified state of joint attention may not be necessary for a psychological understanding of the phenomenon and its functional role.