Singapore - Women are their own workplace enemies when it comes to cracking the glass ceiling, with an international study finding they are less likely to promote themselves and network than their male counterparts.

The 2008 study, part of U.S. behavioral scientist Shannon L. Goodson's new book The Psychology of Sales Call Reluctance, compared almost 11,500 professional women with 16,700 men from 34 countries.

Goodson said professional women in Britain, the United States and China were more likely to promote their interests, whereas women in New Zealand and Sweden are the most timid, followed by Australian and Canadian women.

But overall, women were not doing enough to advance their own careers, she said in a statement.

"Women did not create the glass ceiling, the invisible barrier blamed for limiting their ability to earn what they're worth, but they help maintain it," Goodson said.

"Being able to draw attention to your contributions and competencies at work has become an important part of modern career management, and it is something most women are still unwilling or unable to do as consistently as their male counterparts," she added.

Goodson's research found that while most men had no qualms about touting their contributions, and even sometimes lying about them, women still cling to the myth that self-promotion is "socially unacceptable", "unlady-like" and "morally suspect".

"They believe hard work alone is sufficient to put them on salary and status par with their male counterparts," she said.

"Good work is important, but good work alone does not, as the myth says, speak for itself, you have to give it a voice."

Goodson's research also found that women who had managed to climb up the corporate ladder tended to "take the ladder with them", sometimes even sabotaging the chances of other female workers seeking promotion.

This part of the study, which was conducted mainly in the United States, revealed women executives may not be as encouraging or supportive of female staff.

"This led many women in the study to actually prefer male managers to female managers, claiming men are more consistent and fair-minded than women," Goodson added.

(Writing by Miral Fahmy, editing by Sanjeev Miglani)