Connecticut to ban first cousin marriages, which are still legal in at least 16 states

Connecticut is moving forward with a total prohibition on marriages between first cousins, a decision that reflects a rare bipartisan consensus in this predominantly Democratic state, set to take effect at the beginning of October.

The new law explicitly declares that “no person may knowingly marry such person’s first cousin,” as stated in the bill approved by legislators during the recent session of the General Assembly.

Current state regulations already forbid marriages among immediate family members, encompassing everything from a biological parent to a stepchild. All possible avenues for incestuous relationships have been closed off in the past—except for marriages between cousins.

The initiative was sparked by State Rep. Devin Carney, a Republican from Old Saybrook, who proposed the bill not due to any specific need from his constituents but because he was inspired by recent legislation in another state.

Carney explained, “Someone sent me a news article about Tennessee enacting a ban. When I found out it wasn’t prohibited in Connecticut, I started researching and discovered that over 30 states have such bans, meaning Connecticut lagged behind,” he shared with the Connecticut Post.

His initiative prompted other legislators to review state law, revealing that there was indeed no solid regulation or penalties concerning marriages between first cousins.
“Upon review, we realized we were essentially an outlier among states that did not prohibit it. Scientific evidence indicates that offspring of first cousins face increased risks of genetic defects. Simultaneously, we didn’t want to penalize or affect existing marriages that were permissible under previous laws,” stated State Rep. Steve Stafstrom, a Bridgeport Democrat and co-sponsor of the bill.

With this legislation, Connecticut will join 25 other states in enforcing an outright ban on first-cousin marriages. Several states have implemented their own limitations regarding such unions instead of fully disallowing them.

In New England, Connecticut and New Hampshire stand out as the only states banning this type of marriage entirely. Meanwhile, in Maine, such unions are permitted under specific circumstances, such as for same-sex couples or those able to provide evidence of genetic counseling, according to the Maine state legislature.

Other states in the region typically allow cousin marriages without restrictions.

Additionally, states like Arizona, Illinois, and Indiana may permit marriages between first cousins under conditions related to age or infertility.

As Stafstrom emphasized, inter-family procreation is linked to a variety of birth defects, which can include limb malformations, cardiac issues, premature births, and increased neonatal mortality, according to findings from the National Library of Medicine.

In Minnesota, marriages between first cousins are only permissible if they align with the traditions of indigenous cultures, as outlined in the 2024 statutes.

In North Carolina, only double first cousins—children of two sisters who married two brothers—are able to legally wed, as indicated by the state’s judicial information.

During the Civil War, cousin marriage was legally recognized in all 34 states. Presently, such marriages are allowed in approximately 16 states across the country.

In a notable case from 2021, a New York parent sought to overturn an incest prohibition that blocked them from marrying their own adult child shortly after the state officially banned child marriages.