Humans enjoy categorical perception of speech, colours, faces, and more from the early months of life. In this talk I first offer an account of what categorical perception is and then propose that categorical perception also provides a model for understanding claims about the early developing perception (or cognition) of causal interactions, agents and goal-directed behaviours.

Categorical perception is held to play a role in the acquisition of concepts and in grounding beliefs: early-developing perception (or cognition) of causes, agents and goals is held to provide “building blocks” for the acquisition of concepts and to justify us in believing that such things exist. Does it play these roles? I argue that categorical perception is not essentially a way of being aware of things. From the point of view of a perceiver, all categorical perception typically provides is a signal of sameness or difference. It does not generally provide awareness of in which respect objects of perception are the same or different. If this is right, claims about the role of categorical perception in acquiring concepts and in justifying beliefs fail. The role of categorical perception in development is not to provide building blocks or justify beliefs: it is to make us pause in situations suitable for rediscovering principles our perceptual systems already depend on.