Final answer:
Polyandry refers to a form of marriage where one woman is married to more than one man at the same time and is mostly found in societies with scarce resources and specific cultural practices, such as some areas in Nepal.
Step-by-step explanation:
Polyandry is defined as a form of marriage where one woman is married to more than one man at the same time. This marital practice is considerably less common than polygyny, where one man is married to multiple women. Polyandry is often seen in societies with scarce resources, like certain rural areas in Nepal, where brothers may share a wife, thus sharing resources and inheritance, and minimizing population growth.
The reasons for its rarity compared to polygyny include the higher prevalence of patriarchal social structures and the fact that it occurs in only about 1 percent of the world's cultures. Polyandry, much like other forms of polygamy, can be shaped by cultural, economic, and social factors, and might be practiced due to scarcity of females, an excess of males, or other demographic imbalances. However, contemporary global norms tend to favor monogamous relationships, with polyandrous marriages being an exception.