Why Every State Should Ban First-Cousin Marriage

Delaware’s legislature is debating a bill to recognize first-cousin marriages performed outside the state. The bill’s sponsor is Rep. Madinah Wilson-Anton, a Muslim progressive. A quarter of the people in her district were born overseas. “It’s an issue for my community,” Rep. Wilson-Anton told an interviewer, “and I was elected to be the voice for my community.” She applies the love-is-love language (“I don’t feel like the government should be in the business of telling people who they should marry”) to promote her bill. 

Delaware represents a leading edge as American mores about family form and affinity meet the reality of mass immigration. Consanguinity, which is “marriage or a reproductive relationship between two closely related individuals,” is more common in Muslim and Arab countries than in the West. More than 50% of marriages in Saudi Arabia, Pakistan, and Burkina Faso involve first cousins. In Britain, 2021 estimates suggest that more than 50% of British Pakistanis are married to first cousins—and about 3% of those living in Britain practice consanguinity.

This presents a special problem for American conservatives.

Conservatives rightly think family values are cornerstones to civil society. Among those values is loyalty—husbands and wives stick it out through hard times, just as parents love their own children come what may. However, family loyalty, if taken too far, can compromise public justice, undermine civic virtue, and undermine loyalty to the broader political community. First-cousin marriage is a form of excessive family loyalty that threatens the future of republican self-government. 

Great art depicts how the family and the political community conflict over the loyalty of citizens. The Greek poet Sophocles depicted the conflict between Antigone, who insisted that her traitorous brother receive an honorable burial, and Creon, her uncle and future father-in-law, who erased the importance of family loyalty by demanding that traitors remain unburied with souls left to wander the earth. Creon kept ruling the city and his life ended tragically. His wife and son killed themselves after Antigone committed suicide. The “God Father” trilogy, the great American epic, depicts the tragedy of loyalty as Michael Corleone demands absolute allegiance from those around him and ends up alone as everyone falls short of his standard. 

Western peoples uniquely treated family loyalty as a challenge to republican government; Christianity presented a solution. Joseph Henrich’s book, The WEIRDest People in the World, credits the exogamous Christian marriage and family program, built on monogamy, for making space for community institutions like the Church, the division of labor and its attendant innovations, and, ultimately, for representative government. Mores and laws against first-cousin marriages are, for Henrich, among the pillars of the Christian family program.

While America tolerated first-cousin marriage in law during colonial and founding times, it was never the norm here that it was in the Islamic and Arab world: 23 states banned the practice between 1858 and 1940. Texas banned it in 2005, and Tennessee did so in 2024. Some states today either allow it (e.g., Alabama, Alaska, Colorado and California) or recognize first-cousin marriages when the couple moves into their jurisdiction (Arkansas, Louisiana, and Kentucky). Even though it is still allowed in many jurisdictions, only .2% of American marriages are between first cousins, according to a 2015 study. 

As people from countries practicing consanguinity have been moving to America with increasing frequency, the pressure to legalize first cousin-marriage is increasing. The states with the highest Muslim populations like New York, New Jersey, Virginia, and Massachusetts allow consanguinity. American policy in this area has been a free rider, of sorts. Tolerated in law, first-cousin marriage is stigmatized in practice. But that time may be coming to an end.

Many states ban first-cousin marriage (and also incest) for good eugenic reasons. Malign recessive genes that hardly ever express themselves in children born from unrelated spouses are more likely to manifest in marriages between close relatives. In pursuit of this interest, Illinois and Minnesota only allow consanguinity between infertile cousins.

Yet states ban consanguinity for much deeper reasons of policy traceable to the Christian West’s distinctives. Generally, consanguinity arises in, and causes, an atmosphere of public distrust. When folks around are untrustworthy, a father can at least depend on his family to provide spouses for his children. Trusting more in one’s family makes people outside the family seem untrustworthy. As a result, as Francis Fukuyama argues in his book Trust: The Social Virtues and the Creation of Prosperity, consanguinity encourages nepotism—something that human beings seem hard-wired to practice.

Countries where consanguinity is common have weaker public institutions amidst low trust societies, as Ladislav Holy’s Kinship, Honor and Solidarity and Frank Salter’s Risky Transactions show. It is difficult to establish banking systems in lands that practice first cousin marriage. Loan criteria are not based on ability to pay but on blood—and such practices make banks unstable. Other large economic enterprises are compromised as well. Militaries, dependent on trust, have a difficult time coordinating actions as people shirk away from danger expecting the people from other families to do the brunt of the fighting. The rule of law is compromised and due process becomes a luxury good for those that transcend tribalism. Laws are more likely to become bludgeons in the hands of a tribal mob under conditions of consanguineous nepotism. 

Art, science, and reason agree that excessive family loyalty poses profound economic and political problems. Prohibiting first-cousin marriage may not be welcoming in the current sense put forward by Rep. Wilson-Anton, but it is a ban that makes a society open to justice and prosperity more possible. Delaware should reject this backdoor embrace of first-cousin marriage, and other states should change their laws to ban it.

Scott Yenor is Senior Director of State Coalitions at the Claremont Institute’s Center for the American Way of Life and a professor of political science at Boise State University.

Editor's Note: The opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or views of the Institute for Family Studies.