Women are less likely than men in high-status jobs to be given flexible work schedules to pursue career development and opportunities, according to a recent Yale University study.

The study, published in the July issue of the Journal of Social Issues, found that managers were more likely to grant men flexible working schedules.

Researchers asked managers how they would act if men and women of varying ranks asked for different schedules. The workers represented employees in high-status managerial positions or lower-status hourly positions, researchers said.

Managers were also told the reason for the schedule change request was either for child care or to take professional development courses.

The results were clear: Employers favored giving men more ‘flex time’ in scheduling.

Workers most in need of flexible scheduling and women in low-status jobs with child care needs are among the least likely to receive accommodations from their managers, said the study’s author, Victoria Brescoll, an assistant professor of organizational behavior at the Yale School of Management.

The study also asked employees about whether they thought their requests would be approved or not.

Women in high-status jobs asking for time off for professional development thought frequently that their request would be approved. Men in similar positions asking for flexibility for the same reason were least likely to believe the request would be granted, the study said.

Women may be underestimating the negative consequences of asking and overestimating their true probability of success Brescoll said.

Women’s advancement in the workplace has been a hot issue. Sheryl Sandberg, Facebook chief operating officer, sparked a national debate when she published “Lean In,” which urges women to be more assertive in their professional aspirations.

Billionaire investor Warren Buffett wrote in a May essay for Forbes that women are the key to America’s economic prosperity. Buffett said companies should strive to develop women to boost their profitability.