The development approach of the World Bank and the IMF has been changing over the last decade, culminating In the formulation of the so-called post-Washington consensus in the late 1990s. The leading research questions of this thesis then are: How, when, and why do lOs change their policies? Conventional IR approaches do not provide a sufficient answer. For these primarily explain the creation, purpose and influence of lOs in the context of systemic factors of member-states’ interests and the distribution of power among them. By doing so, they not only neglect the fact that lOs, in particular the World Bank and the IMF, are, to a certain extent, autonomous, but they also ignore the internal processes of these organizations as well as the aspect of organizational culture that might function as a lens through which external pressure is refracted and which in turn shapes how these organizations change their policies. Drawing from organizational sociology, I have developed my own approach to examining the multiple determinants of lO behavior by means of the empirical case of the Bank’s and the Fund’s social (development) policies and their evolution over the last 30 years, employing document analysis and conducting interviews with staff In Washington, DC. The analysis resulted in two major outcomes, one theoretical and one empirical: First of all, the comparatively designed investigation allowed for the concept of an organization’s personality to be derived. This concept was shown to determine the way an organization is perceived by, but also handles, its outside world. Thus, it is a decisive factor, which influences the mechanisms of policy change, or learning within the organization. It was possible to extract four conditions of change in lOs, whose impact vary according to the organization’s personality. Secondly, through studying the developments of one particular policy area over such an extensive time span, it was possible to comprehensively grasp the content of the social policies of the World Bank and the IMF. Consequently, the analysis was able to fill the term post-Washington consensus with meaning and summarize its main aspects.