We argue that the notion of "mental institutions"-discussed in recent debates about extended cognition-can help better understand the origin and character of social impairments in autism, and also help illuminate the extent to which some mechanisms of autistic dysfunction extend across both internal and external factors (i.e., they do not just reside within an individual's head). After providing some conceptual background, we discuss the connection between mental institutions and embodied habits of mind. We then discuss the significance of our view (...) for understanding autistic habits of mind and consider why these embodied habits are sometimes a poor fit with neurotypical mental institutions. We conclude by considering how these insights highlight the two-way, extended nature of social impairments in autism, and how this extended picture might assist in constructing more inclusive mental institutions and intervention strategies. (shrink)