small communities

I was just thinking about small communities that usually stick to themselves. Gypsies are one of them but I'd really know much about them. The one that I was thinking of was born vampires. Which although it is a fake community I know a lot more about. First it's small because it's nearly extinct. They have a hard time conserving and can only have kids with other born vampires. So dating isn't really about love and neither is marriage it's about getting preggers. So the more kids you can have the better the relationship is deemed to be. I can't imagine how ick that is. I mean I love my honey and plan to be with him for forever. I'd hate to think that a decision like that could be made for me by fertility. On another hand I understand not wanting to put people together that wouldn't be fertile. It would be a crappy way to decide love.