probably on the order of 150 people in size. You wouldn’t have been connected to anybody in those early human groups by more than three degrees of separation. If there was this evolutionary process that favored groups that could be in synchrony when it came to, say, hunting large game, or when it came to fending off attacks from other groups, than there would be an advantage to being able to influence people in that group up to three degrees of separation.
X: It seems that through your research, you’re trying to get at an intangible question of what makes a social network in the real world work versus a social network in cyberspace?
JF: The online world is really important for the spread of information. We’re going to have all this work coming out that shows the role that Twitter played, for example, in the spreading of revolution in Tunisia and Egypt. I think you’re not going to find that someone in Egypt had a friend in Tunisia, and that friend got them to do something. In other words, you’re not going to find interpersonal influence. The reason it helped is because [Twitter] is a broadcast medium. All of a sudden, everyone in Egypt could see that the possibility, the probability of success had shifted. It changed because they were able to get exposure to what had happened in Tunisia. So everybody changes all at once—just through information, not through persuasion—their calculus of whether or not they should participate in the protest. The role that social media plays, I think, most of all, is in reinforcing the notion when all people are deciding whether or not to go out that this time we have a better chance at succeeding. Which is a different thing than when we’re looking at health behaviors, for example, that I’m going to start jogging because I heard that you started jogging and you feel great and you’re my friend.
X: How did you get connected with Nicholas?
JF: Our story is a social network story. You have to forgive me, because this story is long. I was in graduate school [at Harvard] and I was very interested in this question of participation. I had been a Peace Corps volunteer [in Ecuador] and I had seen some communities utterly succeed and I had seen some utterly fail and the two communities seemed to be identical in every respect and yet you get these very different outcomes. So when I came back to the United States I wanted to study how is it that communities can get their act together, how is it that you can get people to participate in the public good? A big question in political science that is very closely related to this is this question of why do people vote? When economists think of this question, it’s just another cost benefit calculation, [such as] Is a gallon of milk worth $3.50 to me? If so, then I’ll buy it, if not I won’t buy it.
If you think about voting this way, voting is a paradox. Here’s the reason: We actually pay non-trivial costs to vote. We take time to learn about candidates, we take time out of our day when we could be enjoying leisure time or going to work. We’ll pay for things to vote. We put gas in our cars. So there are these small costs to voting. Yet the benefits to voting are
