"if it's inborn it should be universal" Yeah -- just like lactose tolerance. Right. This is genetic, and it's one of those things that differs by genetic ance

"if it's inborn it should be universal" Yeah -- just like lactose tolerance. Right. This is genetic, and it's one of those things that differs by genetic ancestry. As Sir Richard Burton once said (paraphrasing here), polygamy versus monogamy is pretty much an affair of climate (and what climate your ancestors contended with).