Founded on an analysis of biographies and carriers of top-rank officials and members of the European Commission, this paper suggest that a lot of recent polemic within the EU Institutions (such as Verheugen controversy, Kinnock reform, etc.) are the expressions of the tensions originating from socio-morphological transformations. To put it simply, the gap between the members and the officials of the Commission has never been so wide on this score. Commissioners seem to be gaining in political capitals to the detriment of a professional commitment in European politics, which implies for example a minimum degree of attendance in the political space of the EU or the accumulation of capitals relating to this space. Conversely, the top-level officials increasingly appear to owe their positions to long-term investment in institutions involving the production and, simultaneously, the accumulation of European capitals, a general tendency whereof the meaning is precisely questioned within the conjuncture of the Kinnock reform and more widely that of the political issues which characterised the mid 2000s. Beyond the conventional issue of the differentiation or de-differentiation processes of the political and administrative elites, this approach enables to underline the unique relationship between these staff categories in the case of the EU and to point out, to a greater extent, an opposition between temporary and intermittent EU elites and staff which seems to be a correct indicator of the specific and inequal objectivation process of the European institutions.