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?