For their research, Timothy Judge and his colleagues pulled data of about 3,500 people from three large American studies the National Longitudinal Surveys of Youth, the National Survey of Midlife Development and the Wisconsin Longitudinal Survey. The researchers controlled for factors such as education and job complexity that could skew the results. In all the studies, people who scored high in disagreeableness were found to have earned more than agreeable types. Men who were disagreeable earned 18.31 percent more than agreeable men, a difference that translated to an average of $9,772 a year more for the people in the surveys.