A new study from the University of Colorado-Boulder has shown that spouses tend to have DNA that is more similar to one another than to a different randomly selected person.

The researchers utilized 825 couples. Each participant’s genome was compared to their spouse and then to two other people who were randomly selected. Couples were more likely to be similar to one another than to the people with whom they were randomly paired.

The researchers have noted that based on this study, this “genetic assortative mating” explains about 10% of educational assortative mating. While genetics appear to be a factor in mate choice, it is a small one.

Benjamin W. Dominguea, Jason Fletcherb, Dalton Conleye, and Jason D. Boardmana in the Proceedings of the National Academy of Sciences via IFL Science.