A new study from the University of Notre Dames, finds that less agreeable men, meaning people who are less cooperative at work make about 18 percent more than men with agreeable personalities. However, on the other hand, disagreeable women or meaner women only make about 5 percent more than sweet and kind female coworkers. Experts are saying that people probably judge and perceive men's and women's behaviors differently. The research also found that "hard to get along" women are less likely to be recommended for a promotion compared to assertive men. Disagreeable men earned about $9,800 more than agreeable men a year, while disagreeable women take home about $1,800 more than agreeable women. But do keep in mind, that the term "disagreeable" doesn't necessarily mean rude, but instead, these individuals are probably just more aggressive and harder to negotiate.