The motivation, planning, production, comprehension, coordination, and evaluation of human social life may be based largely on combinations of 4 psychological models. In communal sharing, people treat all members of a category as equivalent. In authority ranking, people attend to their positions in a linear ordering. In equality matching, people keep track of the imbalances among them. In market pricing, people orient to ratio values. Cultures use different rules to implement the 4 models. In addition to an array of inductive evidence from many cultures and approaches, the theory has been supported by ethnographic field work and 19 experimental studies using 7 different methods testing 6 different cognitive predictions on a wide range of subjects from 5 cultures.