It is far easier for them to be disciplined when they are kids, than after they become adults and the police and courts have to do it.
I know a group that figure that out the hard way. As a kid growing up the boy was allowed to do whatever he wanted and there were no consequences for words or actions. When he was 19 or so he got drunk and got rough with his mom and his dad decided that he was just going to show him how it was. The dad took a trip through the front door, screen door, off the porch and the ass whopping that followed got dad a reconstructed shoulder and the boy was none the worse for wear.
