ABSTRACT
Prominent studies have attributed observed changes in aggregation, settlement organization, and exchange systems to changes in socio-political complexity and often to aspects of leadership. This chapter deals with questions of social complexity while attempting to document and explain changing patterns of social organization in one corner of the Mesa Verde region. More spectacular settlements and evidence of elaborate regional systems characterize the post-A.D. 900 archaeology of the region, similar institutions are present prior to A.D. 900, and their investigation is a necessary foundation for understanding later developments. Changes in social organization that appear to require considerable social and economic overhead can be identified in the archaeological record in a number of ways. The period from approximately AD. 720 to 800/810 encompasses definite population aggregation and marks the appearance of the first villages in the region. The available data point to strong periodicity in the formation of population aggregates in the Mesa Verde region.
