The origin of polygamy

If women act on these stated preferences we would expect wealthy men
to have more mates, and there is ample cross-cultural evidence that they do. The importance of resources to women is apparent even in egalitarian societies such as the Ache and the Sharanahua, where the best hunters are able to attract the most sexual partners.

The relationship between wealth and male mating success is consistent with female choice for wealthy males, but it could also indicate differences in competitive ability among men, since a wealthy high-status man is more likely to out-compete his rivals for control over women.16 It is difficult to disentangle these causes of polygyny, and a discussion of this problem is beyond the scope of this paper.

It seems likely, however, that female choice for wealthy, high-status males (or the choice of her kinsmen on her behalf) is an important factor in many polygynous societies. Borgerhoff-Mulder’s fieldwork among the agro-pastoral Kipsigis provides some of the best evidence that polygyny is a consequence of women’s preferences for wealthy men. In a longitudinal study that followed the marriage histories of pioneers over a 17-year period, Borgerhoff-Mulder showed that women new to the area were more likely to choose as husbands men who could offer them more land (i.e., land available to the prospective wife after division among existing wives). Total wealth (i.e., before division) was unrelated to a man’s chances of getting a mate, which indicates that female choice rather than direct male competition is the key to polygyny in this society.