Cousins In Love: Us Law's Complications

Falling in love with your cousin is a controversial topic, with some communities allowing marriages between cousins and others considering it taboo. In the United States, the validity of cousin marriages varies by state law, with some states prohibiting first-cousin marriages and others allowing them with certain restrictions, such as mandatory genetic counseling. The topic of cousins falling in love is not just a legal issue but also raises cultural, religious, and medical considerations, making it a complex and multifaceted subject.

Characteristics of cousin marriage law in the United States

The history of cousin marriage laws in the US

In the US context, cousin marriage was legal in all states before the Civil War. During the mid-19th century, writers and ministers like Noah Webster, Philip Milledoler, and Joshua McIlvaine laid the groundwork for opposing cousin marriages. They were followed by Lewis Henry Morgan, who wrote about the benefits of marriages between unrelated persons and the drawbacks of consanguineous marriages.

The first legal ban on cousin marriage in the US was enacted by Kansas in 1858, and by the 1860s, several other states followed suit, including Nevada, North Dakota, South Dakota, Washington, New Hampshire, Ohio, and Wyoming. This period also saw the passing of anti-miscegenation laws and the expansion of medical and mental-capacity restrictions in marriage laws. These laws reflected prejudices about immigrants and the rural poor, and they contributed to the stigmatization of cousin marriages.

By the 1920s, the number of states banning cousin marriage had doubled. Since then, a few additional states have implemented bans, including Kentucky (1943 or 1946, according to different sources), Texas (2005), and Tennessee (2024). In 1985, Maine mandated genetic counseling for marrying cousins to minimize the risk of serious health defects in their children.

While the laws vary across states, as of February 2025, 24 US states prohibit marriages between first cousins, 18 states allow them, and eight states permit them only under certain conditions, such as age or infertility. Cousin marriage laws in the US continue to be a subject of debate, with some arguing for their repeal based on changing social and scientific assumptions.

The legality of cousin marriage in specific US states

In the United States, cousin marriage was legal in all states before the Civil War. However, by the 1870s, writers and ministers had begun to advocate for "the advantages of marriages between unrelated persons" and the necessity of avoiding "the evils of consanguineous marriage". This shift in perspective was influenced by studies that suggested cousin marriages resulted in physical and mental deprivation in the offspring. As a result, 13 states and territories passed cousin marriage prohibitions by the 1880s.

Today, the legality of cousin marriage varies across different US states. Some states, such as Kentucky, Texas, and Tennessee, have banned first-cousin marriage. Kentucky and Nevada are the only two states that prohibit marriages between second cousins. In contrast, other states like Alabama, California, Colorado, Connecticut, Florida, Georgia, and Maryland allow first-cousin marriage without any restrictions.

Some states have specific requirements for cousins to marry. For example, Maine mandates genetic counseling for marrying cousins to minimize the risk of serious health defects in their children. North Carolina permits first-cousin marriage as long as the applicants are not rare double first cousins, meaning cousins through both parental lines. New York is the only state that allows avunculate marriage, while Rhode Island permits it only between Jews.

While the exact number of Americans married to their first cousins is unclear, a 2015 estimate suggests that 0.2% of Americans are in such relationships. This percentage includes marriages between second cousins, based on studies from 1941 to 1981, as more recent data is unavailable. Despite the existence of laws prohibiting cousin marriage in some states, it remains a rare occurrence in the United States.

Religious beliefs and cousin marriage

The topic of cousin marriage is a controversial issue, with varying religious beliefs and laws around the world. In the US, several states prohibit cousin marriage, with 24 states banning marriages between first cousins. However, some states, like Maine, allow first-cousin marriage if the couple agrees to undergo genetic counselling.

In the past, cousin marriage was legal in all US states before the Civil War. Anthropologist Martin Ottenheimer suggests that marriage prohibitions were introduced to maintain social order, uphold religious morality, and prevent birth defects in offspring. This shift in perspective led to a focus on the potential negative consequences of consanguineous unions, with notable figures like Lewis Henry Morgan advocating for marriages between unrelated persons to avoid the "evils of consanguineous marriage".

When it comes to religious beliefs, different faiths have varying stances on cousin marriage:

• Christianity: The Bible does not explicitly prohibit first-cousin marriages, and it was a common practice in the ancient world, as seen in the story of Jacob, Rachel, and Leah in Genesis. However, age-old laws of the Roman Catholic and Eastern Orthodox churches reject cousin marriages. During the Reformation, the Church of England, following Protestant principles, returned to biblical law, which also aligns with traditional Jewish beliefs.
• Islam: While the Quran does not specifically mention cousins in its list of prohibited relatives for marriage, cousin marriage rates differ among Muslim communities. In Lebanon, first-cousin marriage rates are 30% for Muslims, while in Ethiopia, cross-cousin marriage is rare among Ethiopian Muslims. In Pakistan, cousin marriage is legal and common for economic, religious, and cultural reasons, with a reported rate of over 60% in 2014.
• Hinduism: In India, cousin marriages are prevalent in certain southern states, and Dravidian Hinduism allows consanguineous marriages.
• Other religions: Buddhism, Zoroastrianism, and the Confucian tradition also permit consanguineous marriages.

It is important to note that cultural and regional factors also play a significant role in the acceptance or rejection of cousin marriages within religious communities. For example, in Nigeria, the Hausa ethnic group, which is predominantly Muslim, practices cousin marriage, while the Igbo people, who are predominantly Christian, strictly avoid consanguineous marriages. Additionally, in the Middle East, cousin marriage rates vary, with higher rates in rural and traditional communities and a decline in urban areas.

Medical implications of cousin marriage

Marriage between cousins is a controversial topic, with cultural and legal implications. While it is encouraged and expected in some communities, it is considered incestuous and stigmatized in others. In the US, 30 or 31 out of 50 states prohibit cousin marriage, with eight of those states criminalizing it. The debate surrounding cousin marriage often revolves around the potential medical implications for the offspring of consanguineous couples.

Historically, cousin marriage was a common practice, especially among elites. However, in the late nineteenth century, it came to be viewed as reckless in both Europe and the US, leading to a sharp decline in its frequency. This shift in perception was influenced by reports implicating cousin marriage in various health issues, including deafness, blindness, and mental disabilities. For instance, in 1846, a commission appointed by Massachusetts Governor George N. Briggs to study mentally disabled people concluded that cousin inbreeding led to physical and mental deprivation in the offspring. As a result of such reports, thirteen states and territories passed cousin marriage prohibitions by the 1880s.

Today, the medical implications of cousin marriage remain a subject of debate. Some studies have suggested that the offspring of first cousins are at a higher risk of health problems, including severe genetic disorders and increased childhood mortality. For example, a study in Bradford, UK, found a higher prevalence of recessive disorders among children of consanguineous couples. Additionally, a report by the Dubai-based Centre for Arab Genomic Studies in 2009 linked the high rate of genetic disorders in the Arab world to the practice of cousin marriage. This has led to mandatory genetic screening for prospective married couples in all Arab countries in the Persian Gulf.

On the other hand, some studies have cast doubt on the significance of the health risks associated with cousin marriage. It has been argued that the risk of birth defects in the offspring of first cousins may be equivalent to that of women over 40 giving birth, which is not prohibited. Additionally, the increased risk of genetic disorders may be relatively small and comparable to the risk accepted in other contexts, such as certain medications. Furthermore, the frequency of cousin marriage and the associated health risks may be decreasing due to improved education and awareness, as seen in the example of Manningham, Bradford.

The medical implications of cousin marriage have important implications for public policy and genetic counseling. Some US states, such as Maine, require genetic counseling and screening for first cousins before marriage, while other countries, like Norway and Sweden, have moved to outlaw cousin marriage entirely. The balance between individual rights and public health considerations remains a complex issue in addressing the potential medical implications of cousin marriage.

Same-sex cousin marriage in the US

In the United States, same-sex marriage has been legal nationwide since 2015. However, federal law does not supersede state law regarding cousin marriage, which varies across the country.

Cousin marriage was legal in all US states before the Civil War. However, in the mid-19th century, cousin marriage began to be associated with mental and physical disabilities in offspring. This led to a gradual shift in public opinion and, by the 1870s, concerns were being raised about the "evils of consanguineous marriage". As a result, 13 states and territories had passed cousin marriage prohibitions by the 1880s. By the 1920s, the number of states banning cousin marriage had doubled.

Currently, 30 out of 50 US states prohibit first-cousin marriage, and it is considered a felony in eight states. Kentucky and Nevada are the only two states that prohibit marriages between second cousins. Some states that prohibit 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.

Some factors that states consider when creating laws regarding cousin marriage include whether the parties to the marriage are half-cousins, double cousins, infertile, over 65, or whether it is a tradition prevalent in a native or ancestry culture. For example, Maine allows first-cousin marriage if the couple agrees to undergo genetic counselling, while North Carolina permits it as long as the applicants are not double first cousins, meaning cousins through both parental lines.

While same-sex cousin marriage is not explicitly addressed in US law, it would likely be subject to the same regulations as opposite-sex cousin marriage, depending on the state.

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