The stories about incest, while of anecdotal interest, are simply not true in terms of a widespread problem. The incidence of consanguinity in West Virginia is very low at 0.2% — that means that practically no one in the state is married to a blood-related second cousins (or closer).
West Virginia’s consanguinity rates are indistinguishable from all the other states. In all of the US there are only 250,000 people estimated to be married to a blood-related second cousins.
If you want to see the real problem, all Muslim majority nations have extremely, alarming, deadly rates rates of consanguinity, which leads to low IQs and all sorts of diseases and deformities, not to much crazed behavior.
The consanguinity or inbreeding rate is 51-58% in Jordan, 54% in Kuwait, 58% in Saudi Arabia, 33% in Tunisia, 50% in the United Arab Emirates, 52% in Qatar, 50% in Oman and 68% in Alexandria, Egypt. Similar rates in Afghanistan, Bangladesh, Pakistan, Bahrain, Syria, Turkey and Yemen.
Islam is literally a plague and curse on any population that adopts it.
It’s more of an issue with endodgeny than actual incest. It’s common in isolated areas areas. When there’s a small population with few new people moving in, eventually you get several family groups that are connected several ways. It still can result in undesirable traits getting passed down that otherwise wouldn’t be expressed. Think the blue people of Kentucky. There’s many communities that experience endodgeny, not just Appalachia. Some are isolated geographically, like PEI in Canada, or socially, like the Ashkenazi