Just to go on a tangent (your comment just feels the closest to this particular topic), Hitler was actually a product of incest. His dad/uncle had a habit of raping "marrying" underage girls, including nieces.
Also, there's plenty of records of Hitler being fucked up as a kid, even before WW1. By that point he was particularly anti-semitic, even by the standard of early 1900's Germany. He was also effectively "that kid" that was in everyone's high school that wrote fanfic where they go on a rape/murder spree.
Tbh, Hitler had 0 chance of growing up as a normal, well-adjusted person.