Some theoretical-methodological problems connected with the study of social stereotypes in psychology are considered. The necessity to distinguish between social and psychological functions, regularities, and determinants of social stereotypes is argued. Regularities of the very process of stereotypification are assumed to be the specifically psychological subject-matter. The process is understood as a universal mechanism of inter-group perception which occurs at every level of group interaction and performs an objectively necessary function of promoting the inter-group differentiation. The assumptions are illustrated by the data obtained in two empirical studies where in particular some content, structural, and dynamic aspects of the stereotypification have been dealt with. "Negative initial self-assessment", a new phenomenon first registered in the above studies, which characterize the beginning of the stereotypification process is described.