Culturally institutionalised non-monogamy Polygyny is legally recognised and regulated in many Muslim-majority countries, where Islamic law permits a man to marry up to four wives under specific conditions. In some countries like
Saudi Arabia,
Iran,
Qatar,
Jordan,
Yemen,
Algeria, and
Mauritania polygyny is legal and regulated by a Family Law. In other countries like
Pakistan,
Egypt,
Iraq,
Syria,
Morocco,
Indonesia and
Malaysia polygyny is allowed only under conditions like first wife’s disability or infertility, requires the written consent of the first wife and sometimes of a judge. As part of
Mustafa Kemal Atatürk's secular reforms, Turkey banned polygyny in 1926, replacing Islamic family law with a Swiss-inspired civil code. In
Kazakhstan,
Uzbekistan,
Kyrgyzstan, and
Tajikistan polygyny was prohibited under
Soviet law and these bans were reaffirmed or codified into new national family laws in 1998 after these countries regained independence.
Polyandry is considered incompatible with Sharia law and is therefore not recognised in Muslim-majority countries. Polyandry persists informally in certain traditional societies, such as in the Himalayan regions of
Tibet and
Nepal, where fraternal polyandry helps preserve family property and manage limited agricultural land, and among communities like the
Toda tribe in South India and parts of Himachal Pradesh, though it is not legally recognised. In the United States, Canada, all European countries, and Russia, marriage is legally defined as a union between two individuals, and no form of polygamy is legally recognised. In the United States and Canada, polygamy is strictly prohibited, with violations resulting in criminal penalties such as fines or imprisonment. Across Europe, polygamous marriages are not recognised due to public policy conflicts, gender equality principles, and fundamental legal values. For example, in France and Germany, polygamy is not recognised under civil law, and attempts to enter into such unions can result in criminal charges, denial of marital benefits, or annulment of subsequent marriages. Polygamy is broadly unrecognised in European countries, posing challenges for asylum seekers with multiple spouses, as typically only one spouse is granted a residence permit and international protection. However, some countries may evaluate such cases individually, considering specific circumstances.
Consensual non-monogamy Unlike polygamy, CNM does not involve multiple legally recognised marriages but instead consists of consensual agreements between adults to engage in multiple romantic or sexual relationships. This distinction allows CNM to operate within the bounds of the law in jurisdictions where monogamy is the legal marital standard. At the same time, the lack of legal recognition for CNM relationships means they are excluded from many legal protections, such as inheritance rights, hospital visitation, spousal visas, and parental responsibilities, as existing legal frameworks typically do not accommodate multiple concurrent partnerships. Similarly, in June 2020, Somerville, Massachusetts, became the first U.S. city to adopt an ordinance permitting domestic partnerships involving more than two adults, thereby legally recognising CNM relationships. Consensually non-monogamous relationships have no legal recognition in Muslim-majority countries, and extramarital relationships, even consensual, are typically criminalised.
Secretive non-monogamy Secretive non-monogamy (non-consensual non-monogamy), commonly referred to as
infidelity or
adultery, is addressed differently across global legal frameworks, with variations based on cultural, religious, and societal norms. In most Western nations like the United States, Canada, and much of Europe, while viewed as a moral transgression, infidelity is not punishable under criminal law. Conversely, in several Muslim-majority countries and others with laws influenced by religious doctrine, infidelity is criminalised under
adultery laws. == Social attitudes toward non-monogamy ==