An important part of cognitive development is coming to think in culturally normative ways. Children learn the right names for objects, proper functions for tools, appropriate ways to categorize, and the rules for games. In each of these cases, what makes a given practice normative is not naturally given. There is not necessarily any objectively better or worse way to do any of these things. Instead, what makes them correct is that people agree on how they should be done, and each of these practices therefore has an important conventional basis.

The chapters in this volume highlight the...