In this article I shall argue that the categories a subject employs to codify her perceptions are emergent elements of the social niche her community inhabits. Hence, I defend the claim that categories are primarily elements of the social ontology a certain subject experiences. I then claim that public representations shared in a social niche play a crucial regulative role for the members of that community: in fact, they offer a rule to conceive a certain type or a certain category, (...) e.g. ‘movement’, ‘time’ or ‘space’. In this sense, categories function as normative elements. (shrink)