Cranston, who visited New Zealand last month, said research carried out by consultants McKinsey found five characteristics of women reach the top echelons of business. They feel a job is meaningful, think optimistically, are good at prioritising and networking broadly and speak up and take risks.
Cranston said the last factor was most important otherwise women risked being put into the female stereotype.
New Zealand was the first country to give women the vote and at one point had a female Prime Minister, Governor-General and female boss of the country's biggest listed company.
But the number of women on boards and publicly listed companies remains stubbornly low.
Top women executives have spoken out in recent months of feeling shut out by an old boys network.
Cranston said the problem of low levels of women on boards was not just a New Zealand issue and would not be solved overnight.
She said the biggest issue in her mind was gender perception.
"We perceive women are less good at leadership than men."
Cranston said it had taken some time to recognise that there were hidden gender biases at play.
"The problem is most obvious when there is a man and woman both going for the same job; the male is perceived as having unlimited potential; while female seen as an expert in her area."
Cranston said instead those appointing a candidate need to assess what that person's potential was for leading.
She believes once there are more women in the top executive level it will get easier to get more women onto boards.
"The problem at the moment is that boards are looking for someone with CEO experience and there just aren't that many women there."
But she says there are plenty of women who have run major divisions of companies.
"It's a question of widening the thinking ... re-educating boards on what kinds of skill sets are needed for directors.
"There are corporate women who have spent time advising boards who could easily sit on boards."
Cranston reckons her drive to reach the top of the corporate ladder stemmed from her mother who she describes as a "frustrated genius".
Cranston says having a vision and goals really helped her and she just kept plugging away at them including overcoming her own personal mental barriers.
One of her initial goals was to become a well-known anti-trust lawyer.
Once she had accomplished that she saw herself as successful and then the drive to be famous in that way really went away.
A lot of that preparation helped her for the CEO role which she reckons she got because her firm couldn't choose between two male candidates so picked her instead.
"When I first took the job I felt like an imposter. Then I turned it around. Facing fears in business development helped me."
Mary Cranston
• Age: 66.
• What: Former chair and chief executive of international law firm Pillsbury Winthrop Shaw Pittman LLP.
• Education: Degree in political science from Stanford University, a Juris Doctor degree from Stanford Law School, and a Master of Arts degree in Educational Psychology from the University of California, Los Angeles.
On top
Women who make it to the top:
• Feel job is meaningful.
• Learn to be more optimistic.
• Prioritise.
• Network more broadly.
• Speak up and take risks.
