The uneven ratio of men and women in top jobs at American companies may not necessarily mean discrimination prevails in the workplace. It could mean that men are just more confident than women, says a Columbia Business School study.

When it comes to self-assessment, men tend to put more weight to their performance while women tend to underestimate their performance, the study suggests.

The fact that men tend to work better in leading roles due to their "honest" overconfidence spells the difference in getting leadership roles in firms, the study further finds out.

The researchers set aside discrimination and instead examined how the differences in the way men and women perceive themselves and their performance affect their climbing up the corporate ladder.

Columbia Business School Professor Ernesto Reuben, who led the study, said, "It's not just a matter of telling men not to lie - because they honestly believe their performance is 30 percent better than it really is. Similarly, it's not as if you can simply tell women they should inflate their own sense of overconfidence to be on par with that of men."

Men are naturally overconfident while women tend to second-guess themselves, and this process cannot be altered by mere counseling. It takes a serious amount of self-belief for women to bag corporate leadership roles.

The researchers conducted two studies which both showed that men were more likely to overestimate their performance and to a higher degree than women.

This conclusion advises human resource persons to take with a grain of salt men's account of their previous performance at work. Employers should be aware of the tendency for men to unconsciously inflate their performance, and women's tendency to be modest about theirs.

The study, published by BusinessDaily, also suggests that recruiters should delve deeper into the past achievements of female candidates as confidence during interviews could not yield exact desired results in actual responsibilities for the positions being filled.

In the same manner, confidence of men and women at work will show up differently, which means employers should learn to look past confidence and bearing and really examine results of jobs done.