I have read multiple times that we tend to marry one of our parents. Some even claim there is no way around it. I don't really see it. There are some aspects that are similar between my spouse and my parent, but since a character has very many facets, I could find some similar facets to any person.
Obviously, a person is influenced by their surrounding, especially their close relationships, like their parents. And also, obviously, we tend to stick with what we know - including people that are similar to us and what we know. But that basically just means we tend to marry someone who is similar to us and the milieu we grew up with. I don't see any need for arguing that we marry one of our parents.
What is the evidence and accompanying reasoning for the claim that we marry our parents?
Examples of such claims: