There is a theory, and it's called sadistic child abuse. Maybe optimistically only 20% of people who had wicked and abusive parents grow up to take that sadism out on others. But they have a draw on their peers, as sociopaths, enticing them to indulge in or excuse sadistic acts. And of course they perpetuate it through violence on their own children. Once they reach a critical mass in a society, you have Russia.

If they do it but they're not quite aware of it, and think they're teaching children a lesson, then you have Germany.

And if they do it because they're saving their children's souls, you have red state America.

Of course, it's abuse, a psychotic perversion dressed up as a social norm. But the point is it's contagious.