Sorry, I wasn't clear. Close geographically meant close genetically for all of human history, until the advent of global travel. If you were a woman living in some village in England, all of your potential mates would be somewhat similar genetically, meaning they would have similar features, body types, but also behavior. Stepping out on a husband would be less risky than today, where geographic closeness no longer corresponds with genetic closeness. This is most obvious with mixed race children, but can also be noticed in same race children if the woman cheated with a white person of a distant ethnic group. That's one of the reasons why not having sex until marriage, and adultery, was so socially unacceptable back in the day. It was the only way to be sure, as a man, that your children were actually yours.