Kipsigis women's preferences for wealthy men: evidence for female choice in mammals?

Summary

In contrast to studies of birds, in mammals there is no clear evidence that polygyny evolved through female choice for males with high quality resources. Among the Kipsigis people of Kenya, polygyny may be a consequence of women's preferences for wealthy men, because strong correlations exist between land ownership and the number of a man's wives (Borgerhoff Mulder 1987 a), and the resources men hold are primary determinants of women's reproductive success (Borgerhoff Mulder 1987b). This paper has two aims: first, to test whether Kipsigis women prefer wealthy men by examining the sequence of marriages among a group of pioneers (Table 1) who established a settlement in the territory of their enemies (1930–1949); second, to determine whether women suffer reproductively as a result of polygynous marriage. Data show that Kipsigis women, or their parents on their behalf, preferentially chose men offering high quality breeding opportunities, with respect to the number of acres available on which to settle (Fig. 2) ; controlling for quality of breeding opportunity there is a preference for bachelors over monogamists over polygynists. Analyses of the full demographic sample show that there are reproductive costs associated with having a large number of cowives (Table 2), costs which women attempt to minimize through judicous marital choices. These results are discussed in relation to resource defence polgyny, female choice and, specifically, the polygyny threshold model.