The Chief Justice says a large increase in the prison population during the past decade seems to have been more about fear of offenders than punishment.
Dame Sian Elias made the comment to a conference of psychiatrists and psychologists in Wellington on Thursday.
Dame Sian says it's staggering that the prison muster has risen by 46% since 2001, to reach more than 8700 inmates in March this year.
She says, especially in relation to violent offending, the increase seems to have been less a result of punitiveness than a strategy of containment born of fear.
Dame Sian says societies are more fearful and less willing to risk tolerating those who cannot be trusted to conform to minimum standards of behaviour.
However, she says if that fear is out of proportion, mental health experts are the ones who need to tell the public.
Howard League backs views
The Howard League for Penal Reform is backing Dame Sian's remarks.
Spokesperson Jarrod Gilbert says the Chief Justice is saying the perception of crime is out of kilter with the reality and that should be evident to anybody who cares to consider the situation logically.
"Clearly if you take away the emotion and look at things more logically then that is just an incorrect or poor way of looking at things."