According to Wharton professor Katherine Milkman's new study, released on Tuesday, professors are less likely to want to mentor female and minority students. Especially in fields that lead to the most lucrative careers.

Milkman explained her research on NPR's Morning Edition. To determine how professors respond to different students looking for mentoring, Milkman and her colleagues Modupe Akinola and Dolly Chough created fake student emails with names that are representative of different genders and racial groups. These "students" emailed professors at top universities to see if they could meet about their work. Professors were more likely to respond, and respond positively, to white men. Even female and minority faculty are more likely to help the white guys. Milkman explains,

There's absolutely no benefit seen when women reach out to female faculty, nor do we see benefits from black students reaching out to black faculty or Hispanic students reaching out to Hispanic faculty.

Faculty bias is particularly entrenched in areas of study that lead to the best-paying jobs, like the natural sciences and business. "The very worst in terms of bias is business academia," Milkman says. "We see a 25-percentage-point gap in the response rate to caucasian males versus women and minorities." 

It's this kind of bias that explains why women excel in college but still reach a glass ceiling in their careers, especially in business. Women currently hold 60 percent of bachelor's degrees in the U.S., but that achievement isn't reflected in the number of women excelling at Fortune 500 companies. Next fall, more Latinos will be enrolled as freshmen in the University of California system than whites for the first time. But white students, especially males, will still have an easier time finding a professor to help them transition from college to career. 

In her now-legendary advice book on women and careers, Lean In, Sheryl Sandberg has an entire chapter titled "Don’t Ask Anyone to be Your Mentor." She advises that women seek answers to questions from a variety of people in the office, instead of focusing on finding one mentor. But college is a time when it would be great to have one professor dedicated to helping you with your academic and career development. When female and minority students put themselves out there, ask for help, and get no response or a negative response, it's got to be frustrating. No wonder women tend to have less confidence once they get out into the workforce.