首先修正一个术语，我想还是用等级多妻（hierarchical polygyny）代替等级多偶（hierarchical polygamy），以便容纳两个我原本就暗示了的含义：1）它是关于人类的；2）它是男性单方面多偶的。
According to the Ethnographic Atlas Codebook, of the 1231 societies noted, 186 were monogamous. 453 had occasional polygyny, 588 had more frequent polygyny, and 4 had polyandry. At the same time, even within societies which allow polygyny, the actual practice of polygyny occurs relatively rarely. There are exceptions: in Senegal, for example, nearly 47 percent of marriages are multiple. To take on more than one wife often requires considerable resources: this may put polygamy beyond the means of the vast majority of people within those societies.
Polygamy existed all over Africa as an aspect of culture or/and religion (mainly Islam). Plural marriages have been more common than not in the history of Africa. Many African societies saw children as a form of wealth thus the more children a family had the more powerful it was. Thus polygamy was part of empire building. It was only during the colonial era that plural marriage was perceived as taboo. Esther Stanford, an African-focused lawyer, states that this decline was encouraged because the issues of property ownership conflicted with European colonial interest. It is very common in West Africa (Muslim and traditionalist).
Polygamy has always been a feature of the world. In Africa pologamy expressed itself in the Jewish, Islamic and other native traditions. In all systems there were strict laws which protected the womens position in this traditional African system.
Polygamy became taboo with Colonialism due to the conflict with inheritance in large families, the social-economic threat caused by increased African populations and the Eurocentric Christian values.
However today polygamy is still a reality and is becoming an option in the African Diaspora in response to a social dilemma. Polygamy within the framework of law and balance is a viable aspect of African family systems which is exited from Kemet to Sokoto.
Although most men had only one wife at a time, polygyny was considered both legitimate and good. The average number of wives in polygynous unions was 2 or 3. The maximum in the Great Sandy Desert was 5 or 6; among the Tiwi, 29; among the Yolngu, 20 to 25, with many men having 10 to 12. In such circumstances, women had a scarcity value. Having more than one wife was usually a matter of personal inclination, but economic considerations were important; so were prestige and political advantage. Some women pressed their husbands to take an additional wife (or wives), since this meant more food coming into the family circle and more help with child care.