Enactivists claim that social cognition is constituted by interactive processes and even more radically that there is 'no observation without interaction'. Nevertheless, the notion of interaction at the core of the account has not yet being characterized in a way that makes good the claim that interactions actually constitute social understanding rather than merely facilitating or causally contributing to it. This paper seeks to complement the enactivist approach by offering an account of basic joint action that involves and brings with it basic forms of mental understanding. The paper turns to theories of joint action rather than theories of perception as some enactivists have done (cfr. Gallagher in Conscious Cognit 17(2):535-543, 2008; Thompson in J Conscious Stud 8(5-7):1-32, 2001), to gain insight into the kind of interactions that underpin our understanding of other minds, and in that way, supplement the interactionist-enactive account. In line with Enactivism, the paper argues that this kind of social understanding is practical rather than theoretical and that it is cognitively more basic and developmentally prior when compared to other ways we come to understand other minds.