the very creation of races itself is because of sexual selection which is assortative.
a perfect correlation is 1, and a perfect non-correlation is -1, e.g., tallest man in the world only marries tallest woman or shortest woman. highest correlations are for religion, ethnicity, race, economic status, age, and politics. this is like correlation of 0.9. next is personality stuff, which is around 0.5 correlation, e.g, slobs marry slobs. and while other physical attributes are not as strong, there is an average correlation of 0.2, but for their middle finger length is 0.61
and while propinquity is a contributing factor, sexual preference is obviously one as well. and our sexual image of ideal partners is created from childhood... so you end up looking for someone who reminds you of your parents or siblings.
similarly they have studied quails to determine mating of individuals they have never met before and they preferred first cousins. or the other study with rats who were raised with perfume scented mothers -- they mounted and finished faster when paired with rats who were scented the same than with those who were not once they were adults. we don't prefer our own mother or own siblings, but we want something almost like them. a study of jewish kibbutzes (settlements where children live together in an intimate (non-sexual) setting, like one big giant family) found that only children introduced to a said kibbutz after the age of 6 married another individual within the kibbutz. from a young age these people are "off limits" to you because it's natural behavior, with animals and humans, to not be in an incestous relationship. but you want something LIKE them. so if your family included adopted brothers and sisters of different races you might actually prefer different races, but if not, it's highly unlikely