The Master suppression techniques is a framework articulated in 1945 by the Norwegian psychologist and philosopher Ingjald Nissen. These techniques identified by Nissen are ways to indirectly suppress and humiliate opponents. In the late 1970s the framework was popularized by Norwegian social psychologist Berit Ås, who reduced Nissen's original nine means to five, and claimed this was a technique mostly used in the workplace by men against women.