Explaining Cross-National Differences in Polygyny Intensity

Possible adaptive functions of polygyny include resource-defense, scarcity of men, and countering a high pathogen load, and cultural determinists posit religion and gender discrimination as factors. Using a sample of 32 polygynous countries broken down by urban and rural location, each of these explanations of polygyny was tested in regression analysis. Polygyny increased in tropical countries having plenty of arable land and unequal distribution of wealth (Gini coefficient), supporting the resource-defense explanation. Polygyny also increased in female-biased populations and in countries with a high burden of infectious diseases. In contrast, there was little evidence for cultural determination of polygyny (favorable religion, approval of wife beating, exposure to mass media), although female literacy was a negative predictor. Results thus support the three main functional theories (resource-defense, scarcity of men, pathogen defense) and reject cultural determinist accounts of polygyny.