Another kind of marriage, although uncommon, is the "polygynous marriage".In a family where all the children were female, sisterly polygynous marriage represented the most common choice.
Bigenerational polygamy was present as an application of the mono-marital principle.
Let us consider a family in which the mother died before the son was married.
Bi-fraternal polyandrous marriages were more common than tri-fraternal or quadri-fraternal polyandry, because the latter forms of marriage were often characterized by severe familial tensions (reference missing).
Different mechanisms were employed to reduce the number of sons within a household, such as making one son a celibate monk, or sending away a son to become an adoptive bridegroom to a family without male children.
Polyandry is a marital arrangement in which a woman has several husbands.
In Tibet, those husbands are often brothers; "fraternal polyandry".Studies have attempted to explain the existence of polyandry in Tibet.One reason put forward in traditional literature is that by not allowing land to be split between brothers, Tibetan families retained farms sufficiently large to continue supporting their family.Historically the social system compelled marriage within a social class.When the People's Republic of China annexed Tibet, political systems in many regions of Tibet remained unchanged until, between 19, political reforms changed the land ownership and taxation systems.However, as part of its population control measures, the Chinese government later forbade polyandrous marriage altogether under family law.