Tamsin Saxton in Aeon:
There are also individual differences in partner choice. Your ideal partner is vanishingly unlikely to be my ideal partner, even if we are matched for gender, age and sexual orientation. To an extent, beauty is indeed in the eye of the beholder. But even these differences between people’s preferences are somewhat predictable: a person’s family influences the partner he or she chooses. Several studies have found that, on average, there’s some physical similarity between one’s parent and one’s partner. That is, your girlfriend might well look a little bit like your mother. This physical similarity is apparent whether you ask strangers to compare facial photos of partners and parents, or whether you assess things such as parent and partner height, hair or eye colour, ethnicity, or even body hair.