Masters Theses

Date of Award

8-1990

Degree Type

Thesis

Degree Name

Master of Arts

Major

Anthropology

Major Professor

Michael H. Logan

Committee Members

Benita J. Howell, Richard L. Jantz

Abstract

The purpose of this study is to assess the utility of the Trivers-Willard hypothesis, which predicts that societies of low socioeconomic level will favor female offspring due to their potential ability to marry "up" in the socioeconomic hierarchy. Consequently, these societies should be characterized by a gender-biased sex ratio and low male reproductive success. The materials utilized in this study were collected by Franz Boas in 1891-93. Data sets for the Micmac and the Pacific Northwest tribes were chosen, primarily due to their large sample sizes. Marriage patterns were determined by admixture. Those listed as above one-half Indian were considered to be the same as full-bloods. Those listed as one-half or below were considered to be the same as non-Indians. The number of children by gender were divided according to the marriage patterns. The sex ratio at birth was determined from the survivorship and mortality figures and submitted to a chi-square analysis. Final results showed a gender-bias in the l-I marriages of both tribal groups. More specifically, the Micmac exhibited a greater ratio of males to females than would be expected, while the Pacific Northwest tribes exhibited just the opposite. Mortality rates were utilized to determine if one gender would exhibit higher death rates among the tribal groups. The resulting data were submitted to a chi-square analysis. All tests failed to meet the significance level of .05. A subanalysis of the Pacific Northwest tribes was also undertaken. The first test contrasted the Coastal vs. Interior groups. The second compared the Tsimshian, a matrilineal society, with the other tribal groups having bilateral or patrilineal descent. Both comparisons failed to meet the significance level of .05. Final analysis of all the data showed a possible male bias among the Micmac and a female bias among the Pacific Northwest tribes. The results, however, were inconclusive. Possible explanations of this phenomenon are relative acculturation or Divale and Harris' male supremacy complex. In summary, it can be said that data for the Pacific Northwest tribes appear to support the Trivers-Willard hypothesis. Data for the Micmac, however, do not support the predictions of this hypothesis. Further research is necessary, both with contemporary societies and with other types of historical data, before the Trivers-Willard hypothesis can be accepted as a valid statement about variance in human reproductive behavior.

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