A professor says she thinks that the gender wage gap can partially be due to assumptions managers may have about what kinds of rewards male and female employees may value. - 

Women still lag behind men when it comes to earnings and promotions. Some attribute this to factors like poorer negotiating skills. But this new study offers something else: Ammunition, for women who want to break that cycle. Professor Maura Belliveau of Long Island University in New York set out to learn why men land more significant raises and promotions than men.

Belliveau's study found that two-thirds of available money for raises went to men. She posits that this gap occurs because managers believe that women are more willing to accept "symbollic rewards," such as more respect over pay. The attitude, she says, is more "I get to do something nice for her."

"When they're looking at men and deliberating about a pay raise for men, it's not that they think that men don't value status or respectful treatment," she said in an interview. "But they in no sense think of that as substitutable for a better outcome."

But several surveys show that women value higher pay just as much as men. Take a listen to the interivew above to learn more about Belliveau's findings and how she thinks managers can hedge against potential unconscious biases they may have.

Follow Tess Vigeland at @tessvigeland