But we can get mixed results without beating them. Most kids don't like being beaten. This question isn't just for effect. The answer, I think, is that we want our kids to obey. Adults in jobs which demand mindless obedience tend to beat their children more than people who get to think for themselves.
Kids learn from beatings, no question.
That's why people beat kids, not because parents are sadists. Beating teaches children that, if you're in the right, it's okay to humiliate and hurt weaker people. The problem is that most people most of the time think they're in the right. So the lesson is just that it's okay to hurt people weaker than you. That's what kids say, often, especially after the memory of the pain and humiliation has faded.