Grant points out that the common belief is that the key to success is motivation, ability, and opportunity. But Grant believes there is a fourth key which is how people interact and communicate. When interacting at work we make a choice to give as much as we can or take as much as we can from the interaction. Grant believes that a person’s preference for reciprocity is integral to how successful they are. He defines three specific preferences for reciprocity – Takers, Givers, and Matchers.