This article aims to account for the relationships between the development of the children's political knowledge and the social practices in which they participate. In order to achieve this objective, the following paper examines a series of psychogenetic studies carried out since the end of the 80's in Buenos Aires in school environment, on the political ideas that children and adolescents construct about the national government and the presidential function. This analysis is elaborated in the light of another very recent research, of anthropological orientation and ethnographic perspective, where it is studied the political knowledge elaborated by children and young people who participate in community practices and inhabit houses as illegal tenants in the same city. In this way, a critical comparison is established between these investigations, which centrally includes the methodological aspects, as well as the scope of the results, for a conceptual re-elaboration around the study of the processes of knowledge construction in the political field. [ABSTRACT FROM AUTHOR]