Drawing on concepts and data from psychoanalysis, group analysis and sociology, this volume develops Earl Hopper’s theory of the fourth basic assumption in the unconscious life of groups and group-like social systems. Earl Hopper applies his theory of Incohesion to the treatment of difficult patients in group analysis. Illustrated with detailed clinical vignettes from groups including drug addicts, victims of incest and sexual abuse, and child survivors of the Shoah and concluding with critical commentaries by senior British and American group analysts and psychoanalysts.