Persistence

I recently heard an interview with Paul Tough, author of How Children Succeed: Grit, Curiosity and the Hidden Power of Character. The upshot of this book is that success in college in beyond depends less on IQ or however it is you decide to measure academic intelligence, but more on character traits like persistence and optimism. This is in line with studies of delayed gratification, where researchers found that pre-schoolers who were able to resist eating a marshmallow were more successful later in life.
I've certainly seen my share of anecdotal evidence of the importance of persistence in achieving success. The kids who were at the top of class in elementary school getting to high school and deciding that honors geometry was too hard. The students who entered college as pre-med majors graduating with English degrees. They all had been used to getting by pretty easily, but at some point they hit a wall, and decided that rather than trying to scale it, they would turn aside. But many of the students that were behind those leaders, who were used to things being hard for them, would come to that wall, see it as just another wall, and surpass the students who had coasted along up to that point.
I'd also say that the analogy applies to success in astronomy. Especially in these tough economic times, the people who end up getting permanent positions are the ones who just keep on applying for jobs year after year after year, not necessarily the ones who do the best science.
Now, suppose you are a girl interested in pursuing science, and you encounter a wall. And suppose someone tells you that you can't climb that wall, because you're a girl. Or that if you climb that wall, the boys won't like you. Or you see that none of your friends are climbing it. There are lots of easier paths for you away from the wall.
Suppose you are a woman applying for postdocs in astronomy. Your wall is just a bit higher than your male peers, because of unconscious bias. You get a little less support for climbing that wall, because your graduate mentor seems more interested in grooming his male students than yourself. You have troubling syncing your wall-climbing with your spouse. You don't see many other women climbing the wall. The paths away from your wall are well-trodden, not to mention that it's especially difficult to climb the wall with a baby.
I guess my point is that persistence is a huge factor in success in any endeavor, and women have to persist harder to succeed in science. I'd like to see both a more level playing field, and more support for women in climbing over the barriers to success.