Incest
I've looked around, and I've heard a lot of people as well as apparent experts saying incest causes crazy shit to happen to offspring, but has there ever even been a case?
I've never seen a case of it happening, I've searched google, but not found such a story or even the origin of this myth.
Does anyone know a case or can refer me to something that shows ****ing your sibling will result in children with three eyes and down syndrome?