[MUSIC] Now, when I talk of interdependent behavior, I always give you examples. Like the case of the restaurant or the case of the traffic. Coordinating on traffic the kind of example I gave you, I always presume that the interdependence is not with everybody in the world or with the everybody in America. But it is with people that matter to me in that particular situation, and I call it more technically a reference network. So a reference network is a set of individuals who matter to me when I have to make a particular decision. And of course the reference network will vary from a situation to another. So think of traffic, I'm driving in Philadelphia where my reference network is the people who bike, walk or drive in Philadelphia. I couldn't care less what happens in New York or Baltimore so my reference network is usually local. And the interdependence means that what I expect people in the reference network to do. And what I think they believe I should do or what they think is appropriate or inappropriate to do matters to me a great deal. Let me give you a few examples of reference networks. Well, the first I just gave you, my reference network in Philadelphia is all the other pedestrians, drivers, bikers, whatever on the road. But you are a student, what is your reference network, well, typically, will be your parents who pay the bill. And your friends at school, your group, your gang, and your teachers will also be part of your reference network. And in a restaurant what's a reference network? Well the waiters and the other customers. If you think of child marriage let's say, who is the reference network? Well other families in the area where you live who married their girls very early, and possibly expect you to behave in a similar way. >> The parents also do married their young child because they are compelled to, they belong to a community where it is norm. So they ought to do it because the network in the community do the same thing. The traditional rulers, the religious rulers, all the parents in the same community do marry their young children, especially the young girl very, very early. >> As I said the reference network is usually close to you but not necessarily. There was an interesting case of families of Somali origin some they were immigrated to Minneapolis which is a US City. And that they send their young daughters back in Africa, in their own countries to get genital cutting. Who are the reference networks of the Somali people in Minneapolis who send the girls back to Somalia to be cut? Well the reference network is the people back in their own countries. So the reference network just means the people that you care about when you make a particular decision. These people may not be sitting there with you, or nearby you they may be a continent apart, but they still matter. What they do matter and what they think you should do matter a lot. Having defined reference networks, I want to point out that in all the following lectures. When I talk of social expectations, empirical and normative, I'm always referring to expectations relative to a reference network. The social expectation that matter, those that have an influence on behavior are always expectations about a specific reference network.