The exploration of the mechanisms of cultural heredity has often been regarded as the key to explicating human uniqueness. Particularly early imitative learning, which is explained as a kind of simulation that rests on the infant’s identification with other persons as intentional agents, has been stressed as the foundation of cumulative cultural transmission. But the question of what are the objects of this mechanism has not been given much attention. Although this is a pivotal point, it still remains obscure. I (...) will characterize the notion of action-types and show why they are the genuine objects of cultural heredity. However, this answer is in conflict with the concept of imitation, and the problem arises that, if imitation is conceptualized as simulation and explained in terms of the cognition of infants, the objects of cultural transmission seemingly cannot be passed on by imitation. In order to solve this problem, I propose reconsidering the concept of imitation and to conceptualize imitation as a cooperative activity of infants and adults. (shrink)