A US study has found that men with disagreeable personalities out-earn men with agreeable personalities by about 18 percent where disagreeable women, on the other hand, earn only about five percent more than those who are caring and sweet, LiveScience reported.

So, for women planning on climbing the corporate ladder, playing nice does have its benefits, with disagreeable women being scorned a lot more than men and offered less promotion opportunities.

The study included more than 3500 people across the workforce from those who had recently left school to those in their late seventies.

Men who were disagreeable earned 18.31 percent more than agreeable men, a difference of around $9772 a year more of those surveyed.

Disagreeable women also out-earned agreeable women by 5.47 percent, an average difference of just $1828 per year.

Study researcher Timothy Judge of the University of Notre Dames' Mendoza College of Business said people may judge no-nonsense women more harshly than no-nonsense men.

"Women who appear to be tough or disagreeable get a special kind of scorn directed toward them," he said.

"That sort of neutralises the benefit that they might otherwise receive."

The new research, which will be published in the Journal of Personality and Social Psychology, found that disagreeable women were less likely to be recommended for a promotion than disagreeable men, with men also being seen as strong leaders.

Judge pointed out that disagreeable behavior doesn't necessarily mean beaing rude or nasty, it means being more aggressive at setting goals and negotiating harder than agreeable types.

For women, this "toughness" doesn't win them as many admirers as it does for men, he said.

"Can one become firm and assertive in what one wants but not be seen as aggressive?" Judge asked.

"Women probably have to attend more to not just what they ask for but how they ask for it."

Judge next plans to research what women can do to escape this trap.