Natural experimental models: The global search for biomedical paradigms among traditional, modernizing, and modern populations

Abstract

During the past four decades, biomedical scientists have slowly begun to recognize the unique opportunities for studying biomedical processes, disease etiology, and mechanisms of pathogenesis in populations with unusual genetic structures, physiological characteristics, focal endemic disease, or special circumstances. Such populations greatly extend our research capabilities and provide a natural laboratory for studying relationships among biobehavioral, genetic, and ecological processes that are involved in the development of disease. The models presented illustrate three different types of natural experiments: those occurring in traditionally living, modernizing, and modern populations. The examples are drawn from current research that involves population mechanisms of adaptation among East African Turkana pastoralists; a search for etiology and mechanisms of pathogenesis of an emerging disease among the Yakut people of Siberia; and psychosocial stress, hypertension, and cardiovascular disease in women working outside the home in New York City and among subpopulations in Hawaii. The models in general, and the examples in specific, represent natural laboratories in which relatively small intrapopulation differences and large interpopulation differences can be used to evaluate health and disease outcomes.

Behavioral changes associated with economic development in the South Pacific: Health transition in Vanuatu

“…Countries in the early phases of health transition represent natural experimental models (Garruto et al, 1999) in which the contributions of behavioral, biological, and environmental variables on chronic disease risk can be examined before chronic diseases have become widespread. Such studies often benefit from relatively high degrees of genetic and cultural homogeneity, which provide natural internal controls.…”

Cattle Raiding, Cultural Survival, and Adaptability of East African Pastoralists

“…Given the availability of comparative data for closely related pastoralists in Turkana, where at that time economic development had been limited, we were presented with a natural laboratory in which to quantify effects of economic development and modernization on human health, adaptability, and fltness in a traditional society (Garruto et al 1999). …”

Unfolding epidemiological stories: How the WHO made frozen blood into a flexible resource for the future

“…Garruto, Little, James, & Brown, 1999). For example, when Albert Damon undertook the Harvard Solomon Islands Project, he had to first figure out where people lived and how they were related to each other.…”