All employees must "toot their own horn" if they want a promotion or payrise, but women are particularly timid about doing so, according to an expert in sales psychology.

US-based behavioral scientist Shannon L. Goodson says the fear of self promotion is holding back competent and deserving workers from being recognized for their contributions and prohibiting them from earning what they're worth.

She says "the fear of self-promotion can make you invisible in the workplace", and workers who believe they can advance their careers without self-promotion are "dreamers".

These people have "innocent expectations" and "romantic idealities" around their careers, she says.

Toot your own horn

"Recruiters (and their candidates) need to realize that the hardest-working, best producing and most deserving workers aren't necessarily the ones who rise to the top," Goodson says.

"Getting to the top of any organization requires a two-part approach: competent performance supported by assertive self-promotion."

"Competent performance without assertive self-promotion creates a recognition vacuum. If you don't take credit for who you are and the contributions you have made, someone else in the organization - probably less deserving - will."

She adds: "As an employee, you are responsible for yourself. If you don't talk it up, don't count on someone [else] doing it for you."

Women are their own worst enemies

Goodson's recent study of more than 28,000 employees identifies a clear difference between men and women with respect to self-promotion.

Women, overall, are more hesitant to network and less comfortable drawing attention to their skills, abilities and contributions than men.

"Men are more willing to draw attention to contributions they did (and sometimes did not) make and to participate in social and professional networking opportunities where they can direct attention to their skills and competencies," she says.

"Women are less comfortable promoting their competencies. Many still cling to the myth that all self-promotion is socially unacceptable, un-lady-like, and morally suspect. They believe hard work alone is sufficient to put them on salary and status par with their male counterparts."

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

Among women, however, differences emerge between countries and cultures.

"Professional women in the UK, US and China are among the least reluctant to promote their interests, whereas women in New Zealand and Sweden are the most timid, followed by Australian and Canadian women."

Goodson says her study found that Australian women specifically struggle with "stage fright" and sensitivities about appearing too forward, pushy or intrusive.

Women are unsupportive of their female colleagues

Goodson's study also aimed to explore whether women who had climbed to the top of the ladder tended to "pull the ladder up behind them", as an Australian study claimed a few years ago.

She says her latest research has found that women executives may not be as encouraging or supportive of other women as once thought. "There is a perception that successful women may sabotage the career hopes of aspiring women further down the ladder, and this has led many women in the study to prefer male to female managers," she says.

She notes that while women did not create the glass ceiling, "they help maintain it".