Table 1. Mean age at death
at selected ages:

Mesoamerican precontact populations and others
at various economic-technological levels
mean age at death in years

Birth (age 0)
Age 15
Age 50
Tlatilco, 2930-3250 BPa323754
La Ventanilla, 350-950a364054
Cholula, 850-1560a293554
Copán rural, 700-1000a254460
Copán urban, 700-1000a364157
Teotihuacán, early classicb2442 58
Teotihuacán, late classicb163466
Teotihuacán, 1580-1620b132852
Cholula, 1325-1520c253451
North American Indiansd223555
Primitive agriculturalistsd264568
Model life table, South level 1e204965
Mexico, 1939-41f405870
Sources: aHealth and Nutrition in the Western Hemisphere Database, October 12, 1995;
bStorey Life and Death, pp. 184-5;
cHayward, Demographic study, pp. 221-2 (Table 7.5);
dJohansson, "Demographic History," p. 136;
eCoale and Demeny, Regional Model Life Tables, p. 384;
fCamposortega Cruz, Análisis, p. 321.
Note: Calculations are based on conventional paleodemographic assumptions: skeletal remains are a random sample of deaths for the population studied; the population is closed (migration is nil) and static (crude birth and death rates are equal; therefore the rate of population change is zero). Under these conditions, the mean age at death from age x is equivalent to life expectancy at that age.
Recently paleodemographers have begun to accept the fact that fertility, not mortality, is the principal determinant of the age structure of a population, and hence, of the age structure of deaths (Johansson and Horowitz 1986). The practical significance of this change in thinking is nil. As long as the assumption of a static system is retained, whether one first computes fertility and then derives mortality or the reverse has no practical effect. Both approaches yield the same answer. Problems of bias remain (see also note 19).