Why do some parents not show support or affection towards their children ? Is it because they grew up that way?

My mother believed there were chosen children and slave children. Either you were chosen for training by her cult group (a generational political cult located inside the old CPUSA), or you were to be subdued and fully controlled, mainly through the use of fear, and were to be an unknowing slave, serving the revolution though ignorant of your subservient role. Lack of affection was a standard part of raising a slave child.