This is Volume XIII of eighteen in a collection of the Sociology of Behaviour and Psychology. Imitation has long been an important concept, as well in social theory as in social practices. In their endeavour to explain how societies are organized and held together, allow cultures are transmitted from one generation to the next, social scientists have made wide use of the concept of imitation. As a key idea in theory and practice it has been the subject of much systematic discussion. Originally published in 1945, In this volume the authors have made a fresh attack upon the problem with a set of concepts which seem peculiarly relevant to it. If imitative tendencies are not instinctive they must be learned, the argument runs. discussion of how such learning takes place.