spend 22-52 percent more time in food acquisition than reproductive-age women (depending on the season), and 90-275 percent more time than unmarried girls (Hawkes et al., 1989: figure 2 and table 1). Among the !Kung, while work effort appears to decline with age during the adult years, people over 60 work almost as many hours as younger adults (Lee, 1979: table 9.5).
Quantitative data on food production and food consumption through the life course (measured in units of calories per day) are available for three different traditional groups: Piro, Machiguenga and Aché (see Figures 10-3a - 10-3c: and Kaplan. 1994, for details). The Piro and Machiguenga practice a mixed economy of swidden horticulture, hunting, fishing, and gathering. There is considerable similarity in the age profiles of the three groups. First, children produce much less than they consume, and production does not exceed consumption until 18-20 years of age. Childhood and even adolescence are characterized by very low rates of food production. Second, production exceeds consumption well past the reproductive period into old age. This is particularly evident among the Piro and Machiguenga. Unfortunately, sample sizes for older Aché men and women are extremely low, due to high rates of death associated with disease at first contact. However, data on Aché men show that they produce about twice as much as they consume in their fifties, but in their sixties they produce about a third of what they consume.
This pattern contrasts markedly with age profiles of production among non