When starting and running a business, confidence is often a quality that separates the thinkers from the doers.

In their book The Confidence Code, TV journalists Katy Kay and Claire Shipman dissect the topic of confidence and women. One of their main findings is that women tend to underestimate their capabilities--in contrast to men, who are often quick to jump at an opportunity irrespective of their qualifications, inherently believing that they can always "figure it out." When seeking out new opportunities, women are more likely to hold back unless they feel they are qualified for the job at hand.

This difference has many implications for success, in business and beyond. Most importantly, women aren't taking as many risks and therefore cautiously opt out, while men are quicker to opt in. With that in mind, I recently interviewed three powerful, successful women--Donna Morris, chief people officer at Adobe; China Gorman, CEO of Great Place to Work; and Amy Chowdry, CEO of AnswerLab--to identify the source of their confidence and how the gender difference postulated in The Confidence Code didn't stop them from getting what they want.

Where did you get your confidence?

Morris: It's the way I was raised. I started having part-time jobs when I was 13. When I was 13, I worked at a dry cleaners. At 14, I got a job at a pharmacy. Why I bring those part-time work experiences up is because I had to be responsible for interacting with people much older than myself. I grew up quicker and I had to have confidence. I got promoted early in my career. When I was 30, I was a director, and at 32, I became a VP. I looked younger, and had to be overprepared for things because I was trying to make up for the fact that I was a young woman.

Gorman: From my family--they made all kinds of things possible for me. The second is from a professional perspective. I tried to manage my career. While I was looking for advancement and bigger jobs, I always made sure that I was exceeding expectations of where I was. I am 58, and when I was coming up, I was either the youngest leader or the only female or one of two. But mostly, I was always young. I didn't feel any gender discrimination until later in my career; the discrimination was more because of my young age. Whether I was selling or leading, I always knew they thought, "Who is this kid?" I would work quickly to overcome that by being competent and talking about past experience and being productive and effective.

Chowdry: I had a family of very strong women. I had a great, great aunt who sent herself to college at a time where women were not going to college. She taught herself how to play the stock market. She was frugal and saved aluminum foil, but created a great amount of wealth to help her family go to school. She learned how to fly when she was 70 years old. I think she set a great example for my mother and allowed my mother to go from a social worker to a CEO running her own company. I always had a foundation that anything could be possible.

What is the biggest professional challenge you have overcome?

Morris: On the work side, I would say the opportunity to make considerable changes at Adobe with Check-in. Check-in is Adobe's new unique solution to performance evaluation. I say that because it required taking a risk and making a bold move. The manner of which we measured and monitored was through our annual performance review. I am very proud at not only abolishing the old review process, but because we did it quickly. There was no time to backtrack. I had a clear vision in what we had to do to move toward it and had to be focused on executing that vision.

Gorman: I have led big turnarounds. Somehow, I knew how to do that instinctively. I had a particular perspective on how to turn companies around through people. There are hard challenges with that. I would parachute in and have a team there and do a quick assessment--do we have the right team or people involved? That is easier to work through. You can change that trajectory more easily if you are a transparent, trustworthy leader.

Chowdry: I negotiated a business deal that had a lot of emotion tied to it--the challenge was trying to balance emotions and objectivity when the outcome had implications for me personally and professionally. It was difficult to negotiate on behalf of myself and the company when I knew the other side wouldn't get what they wanted. Empathy can cause you to overthink or be too sympathetic to the other party's needs. I learned first and foremost that if I would do it again, I would leave the negotiation strategy to the attorneys. I would step out of the day-to-day.

In The Confidence Code, the authors say that women tend to underestimate their abilities and men overestimate their abilities. This underestimation holds women back. What's your reaction to their thesis?

Morris: I would not disagree. Sometimes we can be our own worst enemy. Often, I sit down with the emerging talent within Adobe. For example, when a job is posted, if there are 10 requirements, a man will put his hat in the ring if he has less than five. If women don't have them all, they won't go after it. Why are we holding back? Put your hat in the ring.

Gorman: That is where the role of leaders is so important--to encourage everyone to step up and be their complete, whole self. Part of that is culture. You need to focus on development and to identify the rising talent. Not just women, but women in particular need a bit of encouragement. Role models matter a lot. Seeing people similar to you in powerful positions is important.

Chowdry: I don't know if it's overestimating and underestimating as opposed to women wanting to be authentic and honest about capabilities and experience. And with men, it's seeing that there is a "sell." Not that they are being dishonest--they know how to market themselves more effectively. In interviews I have with women, they'll be careful that they understand where their strengths lie and what their capabilities are. When I interview men, they'll say, "Oh yeah, I can do that" and position themselves and market themselves as strong in all the areas. One is not better than the other; there is just a difference.