Contrast this with the Australian Aboriginal people in sparsely populated central Australia (though I think this is fairly universal among the Aboriginal people here.)
They’re not allowed to date, or marry, as far out as their fifth cousin. I was having dinner with a woman from that culture and she filled me in on the details.
“It was a nightmare! You’d go out with your friends to see a movie, or something, meet a boy. Then you’d come home and tell your mum, and she’s ask his name, his parents names, grandparents, where he’s from, then say, ‘Sorry darlin, you can’t date this one, he’s your fourth cousin twice removed’. And somewhere on the other side of town, he’s having the same conversation with his mother.”