The analysis of social mobilizations as "new social movements", a category built in Europe, has been dominant in the approach of Latin-American movements. This article recalls in its first part the specificities of "base movements" born in Latin-America during the 1970's. Then it shows the debates and the different approaches of social mobilizations. While, in Latin-America, the emphasis was put on values, cultural changes and identities, in the United States it was put on the analysis of organizations, strategies and practices. Finally the third part shows the consequences of this scientific divergence on the observation of the institutionalization processes of social movements, as well as on the analysis of opposition in Latin-America in the years 2000.
social movements; theories of collective action; Latin America