When the author began writing the present study in 1947, it was in the belief that she had discerned a pattern of social structure not hitherto fully recognized or described. Completion of the manuscript was delayed, however, and in the intervening years other anthropologists have come to recognize the type. Dr. Paul Kirchhoff, in an unpublished paper entitled "The Principles of Clanship in Human Society," distinguished between the "unilateral-exogamous" clan of traditional anthropological literature and the "conical clan," which is essentially the obok structure to be described and analyzed in the present work. Dr. E. E. Evans- Pritchard, in The Nuer, described segmented lineage structure in a Negro African society and so pointed the way to investigations of the segmented pattern in other societies. Following the publication of The Nuer, British Africanists have come to recognize the existence of a "segmented lineage" structure which is comparable to the obok structure described here.
Although the present study has lost some of its novelty because of delay in publication, the author hopes that it will still contribute to an understanding of social structure and its dynamic processes. Over half the present work is devoted to Central Asia, where historical documents have been utilized to discover the outlines of tribal social structure in the thirteenth century and to trace changes which occurred both in time and in space among several Central Asian tribes through the vicissitudes of the ensuing centuries. From Central Asia the author was led outward in several directions, lured by structural similarities in Southwest Asia, early Europe, and China. The sections devoted to these areas are brief--that on Europe is cursory-- but this extension of the study outside Central Asia has, it is hoped, yielded a broader understanding of the range of variation possible within the type and also of the processes of change in social structure.
Twenty-five years ago, when the author first began her studies of Central Asian peoples, she encountered a confusing number of terms employed in the literature to describe social units among the Turko-Mongol Kazaks. There was no established usage; each author devised his own combination of terms. "Clan," "sept," and "phratry" were interspersed with words derived from the Russian, Turkic, Mongol, or Arabic languages. Most writers were agreed, however, in accepting the existence of clan structure. Brief field work among the Kazaks in 1934 did not produce data which would permit identification of the clan unit; informants employed a single term, djuz, to denote a number of disparate groups, and no one djuz appeared to stand out from any other djuz as a clan.
In 1938/39 the author made a field study of the Hazara Mongols of Afghanistan . . .