Revisiting Hohokam Paleodemography

Abstract

Archaeological evidence documents apparent depopulation of the Hohokam region of Southern Arizona at the end of the Classic period (A.D. 1150-1450). Major population centers were no longer occupied, and many distinctive material culture traits associated with the Hohokam tradition seem to disappear. Proposed explanations include migration, dispersion of the population into less archaeologically visible settlements, and wholesale population decline. The latter hypothesis is attractive partly because of a seminal study of paleodemography and health at the Classic-period site of Pueblo Grande in the Phoenix Basin. That study suggested that the population was not sustainable due to very low life expectancy, a very high dependency ratio of juveniles to adults, and other indicators of biological stress. A hazards analysis of the published demographic data reveals life expectancy at birth in the expected range for prehistoric populations with no evidence of a dependency crisis. Population decline at the end of the Classic period is more likely explained by reduced fertility than by increased mortality. Birth rates are sensitive to cultural and economic forces, and we should look beyond health factors in trying to account for the disappearance of Hohokam traditions.