People who are driven by rewards tend to be the ones who win at games—even when the reward has been removed. Neuroscientists at Washington University tested 31 randomly selected subjects with word games, some of which had monetary rewards of either 25 or 75 cents per correct answer, others of which had no money attached. Researchers believed they would find that the performance of reward-driven subjects would slacken when the reward was removed, but the opposite was true.