People hit children because they enjoy it. Any other reason is a lie.Spanking is most effective when a child is very young and needs a swat on the butt to convince them that they really do have to obey mom and dad. If you haven't got that bluff in by age five, you might as well give it up.
It needs to be done with calculation, not emotion. Kids will pick up quick if you spank out of anger and they will likely grow up and do the same to their kids.