Questions are being raised this morning over whether the controversial anti-smacking bill is actually working.
The University of Auckland longitudinal study Growing Up in New Zealand shows a third of mothers used smacking as a form of discipline and regularly screamed at their kids.
Research Director Dr Susan Morton told Mike Hosking the trend has been going on for a while.
"I think what we're seeing with studies like this is actually what's going on in the home. We know that the law has changed but potentially behaviour at home hasn't, and that's what's concerning."
Dr Morton said we are seeing in the home potentially what's happening in the wider society.
"And the problem is that if violence is tolerated in the wider society and then at home, children are learning that physical punishment is okay and that's something that's likey to be perpetuated to them throughout their lives."
LISTEN ABOVE AS DR SUSAN MORTON SPEAKS TO MIKE HOSKING