In comparison, men employees in their mid to late 20s have high life and job satisfaction and good work-life balance, but those don't pick up for women until they hit 36 years old.
HR executive founder and director Angeline Long said it wasn't a surprise young women -
and men - were unhappy in the workplace.
"If you look at it from management top-down, I don't think a lot of the managers out there know or understand how to manage millennials coming through, and therefore don't understand what motivates and challenges them in the workplace," Long said.
"People's expectations have changed. We have a lot of young, 20-plus people who don't want to be stuck in an office for eight hours of a day... They're looking at flexibility of workplace and not having to fight the traffic, to work at home for a few hours or maybe if they're going overseas, work remotely."
Company managements needed training on how to engage millennials, Long said.
"The way we used to engage staff in the past isn't going to work anymore. We've got to be open to looking at other ways of operating to get the best out of them.
"Expectations of what they want to do in the work environment is not being met."
There were also extra pressures on young women who wanted to start a family earlier in life, Long said.
Research findings show prospects for women progress as they get older, but are still negative, until the 36 to 45 age group when they start reporting positive satisfaction and work-life balance, Haar said.
Women aged 56 years and over were found to be the happiest workers in the workforce, which likely reflected a good career and comfortable home life, he said.
"For women across all ages, we might consider the effects like a Nike swoosh – it dips down deeply at the start, slowly starts rising, and then the trajectory is strong and upwards," Haar said.
"If across time women are like the Nike swoosh, then men are like the Loch Ness monster. A serpent curve of ups and downs until they finally see the light, like Nessie's raised head, at 56-plus years."
Human Resources Institute of New Zealand (HRINZ) president Julia Stones said women aged between 20 and 25 were often in their first job, therefore it was not surprising they were feeling the least satisfied.
"Over 95 per cent of people never plan their career and so when we're talking about that demographic of women, very often they're in their first job - if they've gone to university, and very often they fall into their first job with no really clear idea about why they are doing it or really why they accepted it," Stones said.
It was not surprising that women aged over 55 were at the peak of their job satisfaction, she said.
"In a talent-short market and by that age they would be very comfortable about themselves, identities, what they enjoy doing and what they don't enjoy doing."
