The excavation of Tlajinga 33 (c. 300-650 A.D.), in Teotihuacan, yielded a skeletal population of 171 ageable individuals. This is the first population to be studied paleodemographically from Teotihuacan and the first from a pre-Columbian city in the New World. Various techniques were used to reconstruct the demographic profile of the residents. Life table analysis revealed a population with high juvenile mortality and a relatively short average lifespan, a common pattern in paleodemographic studies. Breakdown of this pattern into two chronological periods revealed that in the earlier period, juvenile mortality was lower, and the resident population probably increased slightly during a time of expansion of the city. During the Late Period, juvenile mortality was very high with the residents declining through a surplus of deaths over births. The life tables further revealed that the most dangerous point in the lifespan was around birth, a pattern not previously studied in the paleodemographic literature. Using paleopathological indicators to study populational patterns for the time of peak stresses in the lifespan, there was indeed evidence of a slowdown in late-term fetal growth and possible problems with maternal nutrition that might explain the loss of a significant proportion of newborns. Also, there was evidence of infections and probable nutritional stress during weaning which may have affected the overall morbidity of the population. Despite the small sample size from Tlajinga 33, the demographic profile clearly revealed a population under a nutritional stress with high mortality, a situation probably resulting from poor public sanitation, limited water supply and inadequate agricultural resources in the city. The patterns of high juvenile mortality and a population that is not reproductively self-sustaining, but declining, are typical of many established preindustrial cities in the Old World. It is informative that this pattern should also have characterized a residential group that is part of an established, densely populated city in the arid highlands of Mexico, where the lower epidemic disease load has been presumed to be less demaging to the pre-Columbian populations. The effects of preindustrial urban living appear to be uniform across environments and cultures.
