ABSTRACT
The overarching challenge we face is to understand the developmental emergence of knowledge. This chapter aim is to characterize joint actions as performed by children in the first years of life. If the Joint Action Conjecture is right, this will be a step towards understanding the developmental emergence of knowledge. But first, what are joint actions? A slightly better way to introduce joint action is by using contrast cases. Contrast cases are pairs of events which are as similar as possible except that one is a joint action while the other is not. Many philosophers and some psychologists hold that all joint actions involve shared intention. They tend to assume that characterizing joint action is fundamentally a matter of characterizing shared intention. It is important to acknowledge that we have not yet said anything very informative about what shared intention is.
