"But when they were told about [the gap], they were more upset about it than the older men, with 37 per cent upset that it was still happening in Australia in 2016," she said.

"Notwithstanding this recognition that there is a pay gap, and that gender bias is the reason for it, 81 per cent of men think that they earn the same as women," Ms van Onselen said.

She said it suggests men aren't necessarily ignoring available information, rather that there is a broader "not in my backyard" mentality about the issue.

A report commissioned by the bank in March showed women's starting pay is nearly 12 per cent less than men for full-time work, and the gap remains for the entirety of their career.

It is estimated the difference is worth nearly $123.4 billion annually, assuming women had the same rate of employment as men, and were paid equally in like for like jobs.

The findings of this latest research, produced in conjunction with The Australian Financial Review/Westpac 100 Women of Influence Awards should help inform the next steps for closing the pay gap because it proves that gender bias – conscious or otherwise – is responsible for the difference, Ms van Onselen said.

"It's why pay audits are really important. When Westpac started pay audits [in 2015], we realised there was some differential. We've now closed the gap on that.


"Transparency of pay and promotion processes is important to women [and] that recognition of pay equality and having a pay audit is really key to that."

The data also showed that women aren't necessarily correct in thinking most men are ambivalent on the issue of gender equality, with responses of men and women showing there is a perception gap between the sexes. Women mistakenly assume men either don't care about gender bias and the pay gap, think it's irrelevant and not their fight, or that it's just too difficult to change.

Such misconceptions show the importance of involving men in the debate and problem-solving on gender equality, Ms van Onselen said.

"That's taking a humanist first, women second, approach to the question of gender diversity."