Abstract

This thesis examines if traditional accounts of shared intention can explain how it works when there's doubt about partner intentions to contribute. Can I plan an activity with you and rely on you in ways required to share intentions when I cannot take for granted that you’re predisposed to cooperate? This question, which reflects some everyday instances of social interaction, raises issues about whether and how shared intention can be possible when there is uncertainty about partner motivations and intentions. I address two potential objections to the idea. First, that the lack of common knowledge precludes sharing intentions. I propose a role for common knowledge in settling matters in shared intention and argue that despite its absence it’s still possible that this function is fulfilled. Second, that this overly weakens a belief requirement on shared intention. I draw on research on individual agency to argue that uncertainty about joint action success needn’t undermine shared intention. Neither challenge therefore precludes shared intention under motivational uncertainty. I address a new concern that under this uncertainty a joint settling condition is not met. I use two authors’ accounts of shared intention to highlight the importance of this requirement, and show that, despite very different methodological approaches, both rely on similar background assumptions to explain how the requirement is met. However, I argue that the presence of attractive alternatives means there’s no prima facie reason why these assumptions hold, presenting a theoretical problem. To solve it, I propose using the notion of mutual, social commitment—a popular tool to reduce motivational uncertainty between agents in joint activity—to ground reliance on others and explain how agents jointly settle matters in these contexts. This would, though, impact how we conceptualise the general connection between intentions and commitments. Despite this potential, I argue that social commitments lack credibility in traditional accounts of shared intention, a particularly acute problem in situations with motivational uncertainty. Finally, I outline a view of interpersonal commitment which responds to certain of the issues faced by traditional theories of commitment. I present a framework for a minimal psychological sense of commitment which arises in joint activities and explain how it allows individuals to settle matters in shared activity when there is uncertainty about intentions. I provide empirical support for the theory and address two concerns it faces. I conclude by showing how the sense of commitment can be a basis for solving the problem of how agents can jointly settle matters under conditions of substantial motivational uncertainty.