Factors Underlying Endogamous Group Size11Editor's note: This paper was originally given at the Ninth International Congress of Anthropological and Ethnological Sciences in Chicago in 1973 and is published in Population and Social Organization, edited by Moni Nag (The Hague: Mouton, 1975). It is reprinted here in its original form except that the tables and figures have been redone. (The authors would like to thank Darby Erd of the Institute of Archaeology and Ethnology, University of South Carolina, for redrawing the figures.) The following paper, “Central-Place Theory and Endogamy in China” (Chapter 7), relates this paper to studies that have utilized central-place theory in China.