I think the main gender bias is that a lot of the powers that be think women will be less decisive and worry about people's feelings too much. They want someone

I think the main gender bias is that a lot of the powers that be think women will be less decisive and worry about people's feelings too much. They want someone to drive the success the company needs. But this quickly falls to our natural tendency to trust the common denominator. So they hire and promote people that think, look and act like them because it's easy and (at worst) they feel they'll be able to easily make adjustments with someone so similar. Just look at sports and all the coaches who go around the carousel with minimal consistent success. One other thing people forget is that a lot of times, promotions are a reward for past behavior, not an endorsement of their abilities. A lot of high performing individuals make horrible managers but it is the only way to acknowledgement past value added. Additionally, these new managers feel like they deserve the promotion and now want to coast a little. Of course, they fall into the same trap as above and usually treat all the subordinates as they see their self and never learn how to manage or lead. As a manager, I see the job as helping your team create maximum business value. Of course, none of this is easy and why so many companies are so completely screwed up. You look around and you see so few CEOs who make a difference over random chance. Most who are this top 0.001% are extremely confident and decisive (but also manipulative aholes). This is also why there can be so much opportunity for disruption. The incumbents are stuck in a quicksand of their own making and everyone has embraced self preservation over value creation. Promoting more woman won't fix that. You need leaders that have the will and dedication to create a culture of ownership, transparency and autonomy.