It's interesting how this all comes about. After all, we all came out of Africa, albeit at different times. Things our culture today have developed as mores have changed drastically over the last few millennia. I've not heard of harems like Solomon had, although Brigham Young had his hands full. Incest. Think of King Mausolus and his bride, who was also his sister.
People today are horrified at hearing about the child brides in Muslim nations, but if you look through records of old Europe, you'll see that the first stages of puberty in a girl, which one author wrote half-jokingly, coincided with her first pubic hair, was a readiness for marriage. Those changes can be as early as 10. The men that married these young girls weren't considered pervs. They had spent much of their teen years building a life to take a bride, so this 10 year old marrying an old man more than twice her age was more common than you think. A married woman in the 1400s would barely be high school age. That holdover could be seen through Appalachia, especially in the first half of the last century. I recall one girl from Tennessee in my Freshman art class that, while only 14, was dropping out to get married. It was an arranged marriage, no less. They may have had to throw puffed rice at the wedding to make it legal, but she got hitched and I never saw,her again.
Speaking of Appalachia, besides marrying young, the close kin courtships were common also due to the remoteness of the mountain region. Unless a boy went to the city, he ended up marrying a cousin more often than not. It got worse if the parents of one were siblings to the parents of the other. Double first cousins.