This from the NZ Herald
As many as 77 per cent of parents aged 25 in a study said they had smacked children, with 12 per cent admitting they severely assaulted a child in the past year.
The data was gathered as part of a Christchurch Health and Development Study and reported in the latest New Zealand Medical Journal. "The use of physical punishment and more severe forms of physical assault/abuse are relatively common among contemporary young parents," the study found.
A separate study in the journal also found smacking was widespread in the Pacific Island community, and hitting children with objects was common.