White people(especially middle class and up) in the US often resort to a hands off style of parenting when it comes to their babies.
After the first few months, they often leave their babies alone at night to, ‘cry it out’ with the rationale that child is ‘learning to be independent.’
However, children that young do not yet have any sort of emotional self-regulation: thus the child is simply learning early that if they are in need, no one will help them.
We can reason that any given culture by default preserves the child-rearing practices of those who survived and reproduced the best.
In this particular culture, did only the ruthless make it and then put their own kids through boot camp from day 1 in order to outcompete their fellows rivals.
On the other hand, I’m pretty sure ‘cry it out’ is a fairly recent development in Western culture.
Just another case of a hungry middle and upper middle class trying to imitate rich people who spent less time raising their own children?