Our adult brains retain a preference for perpetuating good, fair behavior. Simply perceiving ourselves as people who do good deeds and behaving accordingly motivates us to do greater good in the future. In one paid study of one hundred college students, subjects who wrote down a list of past good deeds and were then asked to donate money to a charity gave, on average, over half the earnings they'd made from the study ─ almost twice as much as those who had been instructed to recall previous bad deeds. In addition, subjects who'd taken pains to describe not only how they'd been nice to others but how people responded were likely to donate significantly less than those who focused purely on the actions themselves. In other words, people who seemed concerned about appearances (e.g., the impact of their good deed, as much as the deed itself) were less generous than those who cared more about doing good for its own sake. According to the study, the motivation to do good deeds was more evident in those who recalled their past virtues and those who focused purely on their good deeds than those who recalled their previous bad deeds and those who seemed highly conscious of the appearances of their deeds.