The title of this chapter sets out a topic (the socialization of cognition) and asks a question (what is involved?). To introduce my answer, and to explain what I mean by the socialization of cognition, I start by differentiating between psychologists' approaches to the study of social development and to the study of cognitive development. From the beginning the study of social development reflected a strong interest in the acquisition of values or value-laden qualities: honesty, reponsibility, empathy, friendliness, healthy adjustment, prosocial behavior. It also pointed to the social environment as the main factor in the acquisition of these qualities. What came later was an interest in skills and strategies – the skills needed, for instance, to enter a social group, make friends, ask for help, or refuse a request without disastrous consequences. Often as an accompaniment to the interest in skills and strategies (although not dictated by it), there appeared as well an interest in the effect of internal factors, with a particular emphasis on the unfolding of cognitive capacity – the capacity, for instance, to take the perspective of another, to judge interactions, or to estimate the consequences of an action. In contrast, the study of cognitive development reflected from the start an interest in skills and strategies, and in capacities that unfolded with age. Interest in the impact of the social environment was slow to develop, as was the recognition that cognitive development is marked by the acquisition of values.