Cousin Marriages: Legal Or Not?

Cousin marriage laws are the laws that regulate whether cousins are permitted to marry. The term 'cousin' usually refers to first cousins, but laws may also refer to other terms, such as first cousins once removed or second cousins. These laws are closely related to incest laws, family laws, and sex crime laws. The legal status of first cousin marriage varies across the world and within countries, with some jurisdictions prohibiting cousin marriage, while others allow it. In the US, several states prohibit cousin marriage, with 24 states banning marriages between first cousins, while 19 allow it. In some cultures, cousin marriages are considered ideal and are encouraged, while in others, they are seen as incestuous and are subject to social stigma.

Cousin marriage laws in the US

The legal status of cousin marriage in the US varies from state to state. Marriage between first cousins is illegal or largely illegal in 32 states, and legal or largely legal in 18. Some states only allow certain types of cousin marriages, such as between half-cousins or double cousins. In some states, cousin marriages are only permitted if one of the spouses is infertile, or if the couple agrees to undergo genetic counselling.

The laws surrounding cousin marriage in the US are complex and constantly evolving. Before the Civil War, cousin marriage was legal in all states. However, in the 1840s, a commission appointed by Massachusetts Governor George N. Briggs studied the mentally handicapped and implicated cousin marriage as a cause of "idiocy". This led to a wave of prohibitions, with 13 states and territories passing cousin marriage bans by the 1880s. By the 1920s, the number of states banning cousin marriage had doubled. Despite calls for these laws to be repealed, the trend towards prohibition has continued in recent years, with Kentucky, Texas, and Tennessee all imposing bans since 1943.

The main argument against cousin marriage is the risk of genetic disorders in the offspring. Critics point to studies showing that children of first cousins have a higher risk of developing genetic diseases. However, some individuals have opposed efforts to make cousin marriage illegal, arguing that the increased risk is not as significant as some claim and that it is wrong to arbitrarily restrict the choices of consenting adults.

The impact of cousin marriage laws goes beyond the potential health risks to the children of first cousins. The laws can also affect social order, religious morality, and cultural traditions. Additionally, the enforcement of cousin marriage bans can be challenging and may carry societal costs, such as requiring genetic testing for all couples wishing to marry.

While the debate around cousin marriage laws in the US continues, it is essential to note that even in states where cousin marriage is legal, the practice is not widespread.

Cousin marriage laws in China

In China, cousin marriage has been the subject of changing laws and cultural attitudes over time. Currently, according to the Marriage Law of the People's Republic of China (Article 7), marriages between "lineal relatives by blood, or collateral relatives by blood up to the third degree of kinship" are prohibited. This law came into effect on January 1, 1981, as part of the 1980 PRC Marriage Law, banning marriages between first cousins to prevent birth defects and due to the one-child policy. The ban was maintained in the revised Marriage Law in 2001 and is also encompassed in the Civil Code, effective in 2021. Notably, Hong Kong and Macau, the two special administrative regions of China, do not place restrictions on marriage between cousins.

Historically, cousin marriage in China has had varying levels of acceptance. During the Ming dynasty (1368–1644), all cousin marriage was legally prohibited, but enforcement proved challenging. The subsequent Qing dynasty (1644–1912) saw a restoration of the previous laws, and first cousin marriage became common, especially in rural regions. During this period, cousin marriage was sometimes preferable as it strengthened ties between families. The novel Hong Lou Meng (Dream of the Red Chamber), written during the Qing dynasty, centres on a male heir of a wealthy family and his relationships with his two female cousins, one of whom he eventually marries.

Anthropologists have studied and debated the significance of cousin marriage in China. Francis Hsu, an anthropologist, described the mother's brother's daughter (MBD) as the most preferred type of Chinese cousin marriage, followed by the mother's sister's daughter (MSD), while the father's brother's daughter (FBD) was disfavoured, almost considered incestuous. The patrilineal ties in Chinese culture are crucial in determining the closeness of a relation, and the MBD marriage may be more common due to the greater emotional warmth on the mother's side of the family.

Cousin marriage has been associated with various cultural and economic benefits. In some cases, two clans in ancient China had longstanding arrangements to marry only members of the other clan. Cousin marriage can help preserve family wealth, maintain geographic proximity, keep traditions alive, strengthen family ties, and maintain family structure. However, in the early to mid-20th century, anthropologists described cross-cousin marriage in China as "permissible but not encouraged," indicating a shift in attitudes.

Cousin marriage laws in India

In India, cousin marriage prevalence is 9.87%. The legality of cousin marriage in India depends on the religious and regional regulations of the individuals involved.

For Muslims, governed by uncodified personal law, it is acceptable and legal to marry a first cousin. Islamic law permits cousin marriages, and Muhammad himself performed them, especially between first cousins. All first cousins, including maternal and paternal, are exempt from the ban on certain marriage degrees under Muslim law.

However, cousin marriage may be illegal for Hindus under the 1955 Hindu Marriage Act. The Hindu Marriage Act forbids cousin weddings among Hindus unless local tradition permits it. Section 5 of this act, which regulates Hindu marriages, states that a marriage with one's first cousin is illegal because it falls under the category of forbidden relationships. Such marriages are punishable by up to one month in prison and a fine of up to one thousand rupees under Section 18 of the Hindu Marriage Act of 1955.

The civil marriage law, the Special Marriage Act of 1954, also has a separate list of forbidden marriage degrees for men and women.

Attitudes towards cousin marriage in India vary sharply by region and culture. In North India, Hindus view cousin marriage as illegal and unethical, and it may be considered improper to marry someone from the same community or village. In South India, cross-cousin and uncle-niece unions are preferential, accounting for about 30% of marriages in Andhra Pradesh in 1967, declining to 26% by 2015-2016. Cousin marriage is also more common among Christians in the southern states.

Cousin marriage laws in the UK

In the UK, cousin marriage is currently legal. However, there have been recent calls for its ban, with a bill proposed by Conservative MP Richard Holden in December 2024. The bill is currently under review, with its second reading planned for July 2025. The primary argument for the ban is the potential health risks for the offspring of first-cousin marriages, who are estimated to be twice as susceptible to birth defects and genetic disorders. A study in Bradford found that first-cousin marriages were linked to 30% of cases of birth defects in the studied population. Additionally, children of first cousins were found to have higher rates of learning and speech problems and more visits to hospitals and doctors.

However, opponents of the ban argue that it would be unenforceable and damaging, curbing fundamental freedoms and stigmatising minority communities. They suggest that education, genetic testing, and scientific approaches are more effective ways to address the potential health risks. Additionally, the rate of genetic or congenital problems among children of first cousins is 6%, compared to 3% for unrelated parents, indicating that most children of first cousins are healthy.

Cousin marriage is more prevalent within certain minority communities in the UK, particularly among British Pakistanis, where rates of consanguineous marriages are estimated to be between 40% and 60%. However, there is a declining trend, with a sharp decline observed between 2016 and 2020, and lower rates among UK-born mothers and those with tertiary education. While the majority of Britons disapprove of cousin marriage, younger adults are more supportive, and within the British Pakistani and Bangladeshi communities, 39% believe it should be legal.

Cousin marriage laws and immigration

Immigration laws in the United States are complex, and marriage-based immigration has several crucial factors to consider if you are applying for a visa based on this option. If you are in a first-cousin marriage, the USCIS officials will determine its validity based on the rules and policies of the jurisdiction where the marriage happened and where you intend to live.

For immigration purposes in the United States, a valid marriage is necessary to legalize unlawful presence or status, obtain a family-based visa or work authorization, or seek various waivers. It can also protect you against deportation. Marriages between cousins are considered valid when performed in the state where the couple lives or plans to live. A marriage between first cousins that doesn't meet these conditions will be deemed void by the immigration services.

The validity of first-cousin marriages depends on state law, not federal law. Several states in the United States prohibit cousin marriage. As of February 2014, 24 U.S. states prohibit marriages between first cousins, 19 U.S. states allow marriages between first cousins, and seven U.S. states allow only some marriages between first cousins. Some states prohibiting cousin marriage recognize cousin marriages performed in other states, but laws also exist that explicitly void all foreign cousin marriages or marriages conducted by state residents out of state.

In some jurisdictions, cousin marriage is legally prohibited, such as in China, North Korea, South Korea, the Philippines, some countries in the Balkans, and 30 out of 50 US states. It is criminalized in eight states in the US, the only jurisdictions in the world to do so. In the Middle East and South Asia, cousin marriage is still strongly favored, and has been allowed throughout the Middle East for all recorded history. In the United Kingdom, there has been a great deal of debate about whether to discourage cousin marriages through government public relations campaigns or ban them entirely.

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