Polygyny and the Rate of Population Growth

Polygyny is relatively frequent in the second half of the twentieth century among populations in Africa, a continent with high rates of population growth. It varies from about 37 per cent in Guinea, against about 20 per cent on average in West Africa as a whole, to around three percent in North African countries like Egypt, Libya, or Algeria. 1 It should be borne in mind, however, that the incidence of polygyny measured as a percentage of husbands with two or more wives, is only a direct indicator. The demographic consequences of polygyny, although usually practised only by a fraction of a population, are more pervasive, since they affect the proportion of married women and their age at first marriage in the whole community. Accordingly, a transition from polygynous to monogamous type of unions may have significant effects upon the nuptiality pattern of a country and in turn upon its rate of population increase.

Our considerations are confined to three questions: (1) What are the roots of and motives for the practice of polygyny in African societies? (2) How is it feasible to practice polygyny in societies characterised by a more or less balanced sex ratio? (3) How and to what degree does polygyny affect the age pattern of fertility and the rate of population growth?