In this paper I articulate a notion of constituency orthogonal both to classical and connectionist approaches. I shall consider three structure-in-time connectionist networks (Simple Recurrent Networks, Long Short-Term Memory Models, and Non-classical Connectionist Parsers). I shall argue that explaining compositionality by means of any of these models drives us to an information-processing blind alley. In my view, human combinatorial behaviour must be grounded in sensori-motor activity and the parameter of time. A dynamical notion of constituency will thus be offered.