I think a lot of the normal people's incestuous results is often mislabeled iodine deficiencies amongst others, example Appalachian folk. Depleted soils and confined to it. It fits a nice , 'racist hillbilly kissin cousin rednecks' persona to make you disgusted at a simple deficiency in normal, not as often inbred as told by people. In other words, demonization of those without the need of federal help and health gets squeezed as a result.