Resolving serious cases of bullying in nurses is just about impossible, according to research.

A culture of picking on young nurses is not being dealt with effectively, according to a Massey University researcher.

The idea that nursing is a profession that "eats its young" may be correct, Dr Kate Blackwood said.

Her research was conducted over four years and she found just one out of 34 cases of bullying in three different hospitals across the country were completely resolved. Interventions were not effective.

While sometimes perceived as petty in isolation, the impact of those incidents built up over time. Blackwood said many managerial and senior staff were not fully equipped to deal with those cases.

The idea that nurses "eat their young" came up in her interviews, because first-year nurses were "put through a test", she said.

"It's almost like you have to be subjected to these behaviours."

Massey University nursing professor Dr Jenny Carryer said there were a number of problems that could cause bullying in the profession.

"It comes down to 'he said, she said'.

"It's a very pernicious kind of ... behaviour that is really difficult to address."

While some nursing students did experience "grim times", there were also those who were supportive and caring, she said.

Carryer said it would be wrong to "tar everybody with the same brush".

Blackwood spoke with nurses from three hospitals of different sizes. Due to confidentiality, she could not say which hospitals they were.

The behaviours were often subtle, such as excessive criticism or sly comments.

"A lot of managers see it as a personality difference, not a power difference."

Many nurses did not report bullying, and nearly half of those who did found no action was taken to address the issue.

"At the moment our interventions are not working for us.

"My research isn't alone in saying that ... [resolution] in escalated cases of bullying is almost impossible."

Carryer said a range of issues might lead to the behaviour, including increasing workloads and stress.

"While bullying is a totally counter-productive response, because it simply increases stress, it's really the bad behaviour of people who are feeling pretty desperate," Carryer said.

Nursing leadership had diminished while there was an increasing number of non-clinical managers.

She said most clinical leaders were given a sense of "powerlessness", because they were only able to give advice. She said they could not necessarily create change.

"When you create a sense of powerlessness, some people behave badly."

Blackwood said strong leadership was important, which was sometimes lacking. Many nursing managers had excellent clinical management skills, but their personnel management was lacking.

However, DHBs did not have the resources to address the issue, she said.

There had been some recent change in culture in years past, but there was still a way to go.

"About 10 years ago, you wouldn't even say the word bully," Blackwood said.