Aug. 22, 2010— -- Supreme Court Justice Sonia Sotomayor, Homeland Security Secretary Janet Napolitano and former Secretary of State Condoleezza Rice -- what do these women have in common?
Despite their widely varying political and personal experiences, all three of these powerful women do not have children, and some experts think this fact may have contributed directly to their successes.
A new study from the University of Chicago claims that childless women become more successful in the workplace than women with children.
Men and women have nearly identical incomes and working hours once graduating from college, but 15 years later the men's incomes soar to 75 percent more than incomes earned by women, according to the study.
The only exception to the rule is the small group of women who have never had children and whose pay equals that of their male peers.
Kiki Peppard spent a decade working as a successful bookkeeper before taking leave to spend more time with her children. When she decided to re-enter the workforce following a divorce, she found herself as a mother on the outside of the professional world.
"The very first question I was asked was, are you married? The second was do you have children?" she told "Good Morning America." "I went on 18 interviews and was asked if I was married or had kids, on the 19th one I finally wasn't asked about my kids or husband and got the job."
It's often assumed that women make less than men because they have more career disruptions such as pregnancy and raising children, but the pay disparity between men and women also pits mothers against non-mothers.
Mothers are 44 percent less likely to be hired than women without children, and they are paid $11,000 less, according to a 2005 study from Cornell University.
That bias in this uncertain economy can be devastating to many families and can mean the difference between paying monthly bills on time and going further into debt.