[Someone]

https://en.wikipedia.org/wiki/Assortative_mating:

Assortative mating is a mating pattern and a form of sexual selection in which individuals with similar phenotypes mate with one another more frequently than would be expected under a random mating pattern. Some examples of similar phenotypes are body size, skin coloration/pigmentation, and age. Assortative mating, also referred to as positive assortative mating or homogamy, can increase genetic relatedness within the family.