Plural relationship dating
It is most common in societies marked by high male mortality.
It is associated with partible paternity, the cultural belief that a child can have more than one father.
Polygyny offers husbands the benefit of allowing them to have more children, may provide them with a larger number of productive workers (where workers are family), and allows them to establish politically useful ties with a greater number of kin groups.
Senior wives can benefit as well when the addition of junior wives to the family lightens their workload.
Anthropologist Jack Goody's comparative study of marriage around the world utilizing the Ethnographic Atlas demonstrated an historical correlation between the practice of extensive shifting horticulture and polygamy in the majority of sub-Saharan African societies.
Drawing on the work of Ester Boserup, Goody notes that the sexual division of labour varies between the male-dominated intensive plough-agriculture common in Eurasia and the extensive shifting horticulture found in sub-Saharan Africa.
In Europe, this outcome was avoided through the social practice of impartible inheritance, under which most siblings would be disinherited.
Fraternal polyandry was traditionally practiced among nomadic Tibetans in Nepal, parts of China and part of northern India, in which two or more brothers would marry the same woman.
A similar form of matrilineal, de facto polyandry can be found in the institution of walking marriage among the Mosuo tribe of China.
Polygyny is legally accepted in many Muslim majority countries and some countries with a sizeable Muslim minority; it is also accepted in some secular countries to varying degrees.
Polygyny is more widespread in Africa than in any other continent, especially in West Africa, and some scholars see the slave trade's impact on the male-to-female sex ratio as a key factor in the emergence and fortification of polygynous practices in regions of Africa.
Marriage is the moment at which a new household is formed, but different arrangements may occur depending upon the type of marriage and some polygamous marriages do not result in the formation of a single household.
In many polygynous marriages the husband's wives may live in separate households Polyandry, the practice of a woman having more than one husband at the one time, is much less prevalent than polygyny and is now illegal in virtually every country in the world. If every brother married separately and had children, family land would be split into unsustainable small plots.