An overview of prescientific medicine, evolution, and individual human development is presented in an attempt to discover the generic factors operating in all interpersonal therapies. We hypothesize that the placebo effect rests on the universal human need for a group and, by symbolic extension, a system.
Adler, MD, Herbert M. and Hammett. MD, Van B., "The doctor-patient relationship revisited. An analysis of the placebo effect." (1973). Department of Psychiatry and Human Behavior Faculty Papers. Paper 6.