Marriage: Cousins

Does Judaic law prohibit cousins from marrying? Specifically, would Judaic law prohibit two sisters’ children from marrying?

Shalom!

Thank you for your question.

According to Jewish law, cousins are permitted to marry one another. Indeed, it is noted that the daughter’s Zelophchad married their cousins ( Numbers 36:11 ). Mordechai and Esther were also first cousins. (Esther 2:7)

In fact, the rabbis of the Talmud actually encouraged marriage between relatives. One example is the recommendation for an uncle to marry a niece. (Yevamot 62b).

Not only is marrying a cousin permitted, but it is believed that marriages between relatives makes for a stronger, closer marriage. It is also said to be a recipe for good relations with the in-laws!

Nevertheless, although marrying within the family is permitted, it is not for everyone. So too, the closer the relation, the more concern there are for genetic issues and complications. One who decides to marry a cousin should definitely be tested. This is especially true for Ashkenazim who are known to have a predisposition to genetic concerns.

Although, there is no confirmed rule, it is said cousins that bear resemblance might have more genetic complications than cousins who don’t resemble one another. In other words, when each cousin resembles the parent who is not blood related to the other cousin’s parent there is less likely to be genetic concerns.

It is interesting to note that some countries (and some states in some countries) do not allow cousins to marry! As such, Jewish law would not allow cousins to marry each other in such places even though it is inherently permitted! This is because Jewish law also requires us to follow the laws in the places we live.