INTERSECTION OF ECONOMICS, HISTORY, AND HUMAN BIOLOGY - SECULAR TRENDS IN STATURE IN 19TH-CENTURY SIOUX INDIANS

An unusual confluence of historical factors may be responsible for nin eteenth-century Sioux being able to sustain high statures despite endu ring adverse conditions during the early reservation experience, An ex ceptionally long span of Dakota Sioux history was examined for secular trends using a cross-sectional design. Two primary sources were used: One anthropometric data set was collected in the late nineteenth cent ury under the direction of Franz Boas, and another set was collected b y James R. Walker in the early twentieth century. Collectively, the da ta represent the birch years between 1820 and 1880 for adult individua ls 20 years old or older. Adult heights (n = 1197) were adjusted for a ging effects and regressed on age, with each data set and each sex ana lyzed separately. Tests for differences between the adult means of age cohorts by decade of birth (1820-1880) were also carried out, Only on e sample of adults showed any convincing secular trend (p < 0.05): sur prisingly, a positive linear trend for Walker's sample of adult males. This sample was also the one sample of adults that showed significant differences between age cohorts. The failure to find any negative sec ular trend in this population of Amerindians is remarkable, given the drastic socioeconomic changes that occurred with the coming of the res ervation period (ca. 1868). Comparisons with contemporary white Americ ans show that the Sioux remained consistently taller than whites well into the reservation period and that Sioux children (Prince 1989) cont inued to grow at highly favorable rates during this time of severe con ditions, A possible explanation for these findings involves the relati vely favorable level of subsistence support received by most of the Si oux from the US government, as stipulated by various treaties. Conserv ative estimates suggest that the Sioux may have been able to sustain n et levels of per capita annual meat consumption that exceeded the US a verage for several years before 1893.