We all know people who are takers. Takers are self-serving: they love to get more than they give and use others for personal gain. Luckily, most people don’t approach their interactions this way. After studying these dynamics for a decade, it turns out that the vast majority of people operate like matchers, striving to keep an even balance of giving and receiving. Matchers follow the norm of reciprocity, trading favors quid pro quo.