Say the word 'negotiation' and the images that pop up in our minds might be that of a beefy trade unionist, or a confident male executive, or even a slick car salesman.

What is less likely to come to mind, apparently, is the image of a confident woman twisting her adversaries into knots and emerging triumphant with a done deal. In her book on gender and negotiation, "Women Don't Ask", Linda Babcock, an Economics professor at the H. John Heinz III School of Public Policy and Management at Carnegie Mellon, says that most women, on hearing the word 'negotiation', want to cringe.

In her research, Babcok noted that when men were asked to pick a metaphor to describe the negotiating process, they tended towards activities such as "winning a ballgame" or a "wrestling match". Women, on the other hand, tended to lump negotiating in the same category as, say, "going to the dentist."

Now, while most women negotiate successfully countless times every day (it's no easy matter persuading a teenager not to wear clothes that will shame you in public or returning an expensive outfit to a shop that has no desire to take it back!) there is something about the idea of negotiating in our working environment that seems to have many women looking longingly for the exit.

The evidence of this gender divide, says Babcock, starts early, citing her time as director of the Ph.D. program at Carnegie Mellon when she noticed women students were less inclined to ask for things.

"Male graduate students asked for all sorts of things — travel money to go to conferences, exemptions from course requirements, opportunities to teach courses of their own — that the female students rarely asked for," Babcock says. "Looking at the repercussions down the road, it became clear that, as a result, the female students were missing out on a lot of resources and opportunities from which the men were benefiting."

It might spur us on to become better at this if we really appreciated how much it costs us as women to be poor negotiators in the workplace.

According to a Harvard study, "When Does Gender Matter in Negotiation?" by professors Hannah Riley and Kathleen L. McGinn, their research showed that "women tend to enter salary negotiations with lower pay expectations, which are then ultimately fulfilled." In their field study of MBA salary negotiations, they found that "males negotiated significantly higher increases on initial salary offers than did female peers."

In fact, according to Babcock, "Women are more pessimistic about how much is available when they do negotiate and so they typically ask for and get less when they do negotiate—on average, 30% less than men."

It is crucial that women negotiate from the very start of their careers, she says. "We calculated that just by not negotiating her first job offer — simply accepting what she's offered rather than negotiating for more — a woman sacrifices more half a million dollars over the course of her career. This is a massive loss for a one-time negotiation; for avoiding what is usually no more than five minutes of discomfort."

So, if by avoiding or dreading negotiating – in surveys, 2.5 times more women than men say they feel "a great deal of apprehension" about negotiating and women will pay as much as $1,353 to avoid negotiating the price of a car – women are selling themselves short, what’s the solution?

Traits such as empathy and caring are usually more closely associated with women than men and some studies suggest that women, having built relationships with colleagues, often regard their fellow employees as family and take their personal needs into account. This can sometimes lead to situations where women can find themselves being taken advantage of or taken for granted.

But, while satisfying, blaming Mother Nature for our predisposition to caring rather than competing, still doesn't solve the problem.

The answer may lie in women learning to adapt their mindsets and by expecting more, empathizing less and taking a more assertive view of their self-worth. Because, according to Babcock's study, women are more pessimistic about how much is available when they do negotiate and so they typically ask for and get less when they do negotiate — on average, 30% less than men.

Through training, mentoring and modeling successful negotiators, women can successfully learn techniques and adopt strategies that will break them out of their caring comfort zone and enable them to recognize and demand what they are due.

Whether it's to get a discount on a car or a seat on the Board, negotiation is the name of the game. Failing to do so, as these studies show, can prove to be extremely costly.