Oh my goodness! How do you expect to raise your children when you do not understand basics of his/her biology and brain functions. It's not that hard to read a little. 
People who let their children "cry-out" hurt them, period! Long stressful conditions damage brain cells. 
**Instead of training your children like animals try to understand their needs and meet them.** And then everything will look different. It is hard for us, who were brought up like that, but just break the "training" circle and understand your children.
For those who would like to know more, read books by Scandinavian author Juul Jesper - Your Competent Child, Family Life and other books.