Stalin and Hitler suffered objectively shitty childhoods, especially from a modern perspective. However, compared to the majority of men at the time, what they experienced was typical and maybe even above average. Millions of young men, including some who reached positions of power, suffered childhood abuse without being responsible for the deaths of millions. Stalin and Hitler's basic lack of respect for the value of human life stem from much deeper issues than occasionally being beaten because they resisted the will of their parents. I know more about Stalin's background than Hitler's, and from what I understand he lived a pretty decent childhood for the time. His family was poor and his father was an abusive, absent drunk, but Stalin was always surrounded by wealthier family friends who gave enormous favors to Stalin and his mother because of his obvious talent. They paid to make sure he went to the best schools and gave him money for clothes, so Stalin wasn't exactly some supervillian chained to a radiator and beaten until he was evil. What sets Stalin apart was his early fascination with violence, a rigid us-vs-them mentality, an obsession with wielding power, and being an enormously gifted student.