My research is a part of a collective research project entitled "Rockefeller Foundation Fellows in the Social Sciences (1920-1970): Transnational Networks, Construction of Disciplines and Policy Making in the Age of Globalization." (coordination: Ludovic Tournès, University of Geneva/Michael Werner, Ecole des hautes etudes en sciences sociales, Paris). This project analyzes the role of the Rockefeller Foundation (RF) in the shaping of the social sciences between the 1920s and 1970s, especially through its fellowship program. It is based on a study of fellows, the goal of which is to reconstruct their professional careers and trajectories in the long run, before, during, and after their fellowships. The worldwide geographical scope of the project gives us the opportunity to go beyond national borders and to draw a global map of the transnational networks of social scientists in the construction and development of which the RF played a prominent role. In following the fellows' careers, we also study the way social sciences were used, both at the national and international levels, as intellectual tools in the elaboration of public policies, especially through the channel of expertise.