Aging and efficacy of work: a methodological discussion.

Based on a comparison of various human work systems in different cultures, the relationship between efficacy of work and aging is highlighted as a basic component. Age-dependent and age-independent individual variations in labor efficiency in subsistence or nonindustrial societies, which were disclosed in the author's field investigations, are compared with those in industrial societies. Human ergological implications for industrial workers' retirements because of their contracts are also discussed in relation to the behaviorally similar but freely organized work patterns in subsistence societies.