Being a parent can be a very long and challenging learning curve.
But there are a few lessons you gradually pick up on - and one of the key ones is that children will do what you do; NOT what you say they should do.
They are there to mimic; you are there to model.
So if you hit them, the chances are that at some point they will hit also.
Which is just one reason why Sue Bradford's 2007 repeal of the defence of parental "reasonable force" in the Crimes Act when physical violence is used on a child - the so-called "anti-smacking" legislation - was so important.