According to conventional wisdom, highly successful people have three things in common: motivation, ability, and opportunity. If we want to succeed, we need a combination of hard work, talent, and luck. The story of Danny Shader and David Hornik highlights a fourth ingredient, one that’s critical but often neglected: success depends heavily on how we approach our interactions with other people. Every time we interact with another person at work, we have a choice to make: do we try to claim as much value as we can, or contribute value without worrying about what we receive in return? As an organizational psychologist and Wharton professor, I’ve dedicated more than ten years of my professional life to studying these choices at organizations ranging from Google to the U.S. Air Force, and it turns out that they have staggering consequences for success. Over the past three decades, in a series of groundbreaking studies, social scientists have discovered that people differ dramatically in their preferences for reciprocity—their desired mix of taking and giving. To shed some light on these preferences, let me introduce you to two kinds of people who fall at opposite ends of the reciprocity spectrum at work. I call them takers and givers. Takers have a distinctive signature: they like to get more than they give. They tilt reciprocity in their own favor, putting their own interests ahead of others’ needs. Takers believe that the world is a competitive, dog-eat-dog place. They feel that to succeed, they need to be better than others. To prove their competence, they self-promote and make sure they get plenty of credit for their efforts. Garden- variety takers aren’t cruel or cutthroat; they’re just cautious and self-protective. “If I don’t look out for myself first,” takers think, “no one will.” Had David Hornik been more of a taker, he would have given Danny Shader a deadline, putting his goal of landing the investment ahead of Shader’s desire for a flexible timeline. But Hornik is the opposite of a taker; he’s a giver. In the workplace, givers are a relatively rare breed. They tilt reciprocity in the other direction, preferring to give more than they get. Whereas takers tend to be self-focused, evaluating what other people can offer them, givers are other-focused, paying more attention to what other people need from them. These preferences aren’t about money: givers and takers aren’t distinguished by how much they donate to charity or the compensation that they command from their employers. Rather, givers and takers differ in their attitudes and actions toward other people. If you’re a taker, you help others strategically, when the benefits to you outweigh the personal costs. If you’re a giver, you might use a different cost-benefit analysis: you help whenever the benefits to others exceed the personal costs. Alternatively, you might not think about the personal costs at all, helping others without expecting anything in return. If you’re a giver at work, you simply strive to be generous in sharing your time, energy, knowledge, skills, ideas, and connections with other people who can benefit from them. It’s tempting to reserve the giver label for larger-than-life heroes such as Mother Teresa or Mahatma Gandhi, but being a giver doesn’t require extraordinary acts of sacrifice. It just involves a focus on acting in the interests of others, such as by giving help, providing mentoring, sharing credit, or making connections for others. Outside the workplace, this type of behavior is quite common.