Nearly 60 per cent of New Zealand women were comfortable boosting cleavage to attract attention whereas fewer than half Australian women surveyed shared such confidence.
The finding has stunned Sydney socialite and former New Zealand broadcaster Charlotte Dawson.
"It's incredibly surprising," she told the Herald on Sunday. "I would have said it was the polar opposite. Having lived in Auckland, I would have found New Zealand women far more conservative than Australians in using their breasts."
Dawson said she is a D-cup but "tended not to put my bootie out there as much these days".
The Pleasure State My Fit Cleavagely Correct survey found nightclubs the top spot for flaunting as much cleavage as possible. This was followed by first dates and crossing paths with an ex-partner. It was even considered appropriate to turn up to a wedding or work Christmas party with plenty of bust exposed.
However, when it came to work or family get-togethers, the survey showed less was more.
This included meeting future parents-in-law for the first time, interviews and starting a new job.
Psychologist and social commentator Sara Chatwin said the survey found some unexpected results.
"I was interested to see how cleavagely confident we Kiwi sisters are."
Chatwin, who was born in Australia but raised in New Zealand, said a woman's looks often affected how she felt. If she was comfortable and in control, she would feel confident in any situation, Chatwin said.
The survey of 500 men and women in New Zealand and 1000 in Australia was commissioned by Bendon in conjunction with the release of a range of cleavage-enhancing bras.