Klaus Holzkamp (November 30, 1927, Berlin – November 1, 1995) was a Germanpsychologist. He worked as a professor at the Free University of Berlin. He took a central role in defining critical psychology based on the works of Karl Marx. Holzkamp's main message is that mainstream psychology serves the interest of the power elite by disregarding the ability of humans to change their life circumstances. In a standard scientific study in the field of psychology the test setting is taken as a given, unchangeable fact, while in real life people may organize themselves and transform society.