There are often future consequences for your current behavior. You can't just do whatever you want because if you are selfish now, it'll come back to bite you. In order for any of that to work, though, it relies on people caring about you being cooperative. There has to be a norm of cooperation. The important question then, in terms of trying to understand how we get people to cooperate and how we increase social welfare, is this: Where do these norms come from and how can they be changed? And since I spend all my time thinking about how to maximize social welfare, it also makes me stop and ask, "To what extent is the way that I am acting consistent with trying to maximize social welfare?"

DAVID RAND is Assistant Professor of Psychology, Economics, and Management at Yale University, and Director of Yale University’s Human Cooperation Laboratory. David Rand's Edge Bio page [2]