Are people attracted to other people that look like them?

i heard this somewhere, though i can’t remember if it was from a credible source. apparently the explanation for this is that by picking a potential mate based on how similarly they resemble you, the better chance you have of passing on your defining genes, or something. i was wondering if there was any truth to this, especially because lately i’ve realized that many of the people i’m attracted to have similar general traits to myself (pale, light colored eyes, brown hair, etc). i have also been told that my ex and i looked like brother and sister, which is creepy but regardless. on the other hand, i am also attracted to a fair amount of people that look nothing like me, so what’s the deal?