[Why do so many arts and social scientists have huge difficulties accepting (evolutionary)biologically based opinions for gender differences].
The contribution deals with the wide-spread rejection of (evolutionary) biological founded statements concerning sex differences by social sciences and arts, which are not based on objective objections, but are ideologically justified. The starting point therefore is to be seen in the justified critique of the biological legitimized racism and sexism in the sixties and seventies of the last century. The continuation of this rejecting position, though the modern biology has changed itself essentially, can be explained psychologically by Festinger's "Theory of Cognitive Dissonance".