[The role of gender in intersexual experiments in the second half of the 20th century].

This paper shows the formation of the psychological concept of gender from the testing of a new intersex treatment in the 1950s. By analyzing the initial refusal and final success of the new concept and guidelines in the German speaking medical community, it points to the decisive role of treating intersexuals as "experiments of nature" for the clinical research in psychosexual development. This new technology brought the divergent problematizations of "ambiguous sex" in line thus bridging the gap between scientific and clinical approaches and providing the material basis for turning gender into a scientific and practical entity.