Studying U.S.-based real estate agents over a nine-month period, we found that those who scored higher on the questionnaire measure of proactive behavior sold more houses, earned higher commissions, and generated more listing agreements than those with lower scores. This was true even after measuring and controlling for other important factors. Specifically, people with high general intelligence and years of experience tend to be successful sales agents. So we measured these and other dimensions of personality related to sales success: conscientiousness (hardworking, focused, dependable) and extraversion (outgoing, gregarious). Scores on the proactive measure predicted sales success even above and beyond these other variables