One question should be asked of the people who run heavily male-dominated businesses: "Are you sure - really sure - that the overwhelmingly male leadership in your company is entirely down to merit? That only one or two women were good enough to come through?"
These are tough questions because most people sincerely believe they are open-minded. That they - rigorously and fairly - choose the right person for the job. That they have no bias. In fact, what they have is unconscious bias.
One of the best examples of unconscious bias surfaced, not in business, but in music. People running orchestras believed they just wanted to pick the best players for those orchestras. They were - they believed - gender blind. However, 30 years ago out of the, on average, 100 players in a full orchestra, only three or four might be women. Today, it's 30 or 40 - and rising.
This changed because someone decided to take 'gender blindness' literally. They decided to set up 'blind auditions', where the musicians play their instrument on stage behind a screen. Nobody can tell whether the player is male or female. Women even take off their shoes before crossing the stage so the sound of heels doesn't reveal gender.
Blind auditions proved to be the best way to prevent unconscious bias. It's an approach that doesn't blame anybody. It just changes reality. Of course, it's difficult to apply the 'blind audition' principle in business. But it serves as a reminder of how pernicious unconscious bias is and how rigorously it must be guarded against.
When I got my first banking job, there was a theory that if you wanted to get to the top in business, you needed to be 'one of the lads'. Playing golf, acting macho, living the 'work hard, play hard' culture. That was tough to challenge - especially when you're new in the door. But as I settled into my career, I had the confidence and the perspective to really think about this. And I thought, no: that's not for me.
I wasn't going to imitate a certain type of behaviour to make progress in my career. I wasn't going to ape a man to evolve my career. That approach doesn't work.
No one should have to be something that they are not, and no woman should have to be one of the lads. Being great at your job should be enough.
But we also have to be clear-eyed about the challenge, and open to trying new things. Creating an equal -opportunities workplace is a task for all of us - individuals and managers. It's also one of the toughest tasks we face today.
Last year I announced that we in Bank of Ireland would have 50pc female representation in senior management and leadership appointments by 2021. I set out this target because despite half the population being female, this is not reflected in our management teams. This challenge is not unique to Bank of Ireland, but we have to take steps ourselves to fix it, and for good reasons.
More diversity means more diverse thinking and opinion, more challenge, and less groupthink - ultimately leading to better decision-making. And, we in the bank serve a diverse society. We should, I strongly believe, reflect the diversity of the communities we live and work in.
Since announcing that target, our senior management appointments have been made along a 42 to 58 female-to-male ratio. So, while we have more to do, what we have done so far has improved things in our company. And this leads me to be even more confident that we are on the right track: that we can achieve the gender-balance target we have set ourselves.
We continue to challenge ourselves to do more. We have made inclusion and diversity central to our sourcing and procurement processes, ensuring suppliers have active policies in place. Tomorrow we will launch a new Code of Supplier Responsibility that clearly states the expectations we have of our suppliers in respect of inclusion, diversity, and broader human rights.
Whilst I strongly believe they help - and are required - targets are just one aspect of how we approach workplace diversity. At a higher level, we need to build a corporate culture that responds to the constantly changing realities of women's lives, and that adapts to these. We need corporate people-policies that reflect the variety of women's life experience. And we need to be imaginative, creative and flexible so that - in the workplace - each and every one of our colleagues can reach their real potential, and all can thrive.
Francesca McDonagh is Group CEO of Bank of Ireland