[datavirtue]

My vote as well. Proximity and "stickiness" to the mother. Likely not a thing if the father moves on to the next region/town after sireing a child. I think back to the isolated humans encountered by the British when working on their rocket programs. Basically groups of women that men moved between, impregnating. Move into a group, kill a child or two and/or fight other males, impregnate someone and move on. I overlay this behavior whenever I try to figure people out.