How Do You Get Clustering and Small Degrees of Separation?

We know that's not the way human society is organized. How do you get clustering and small degrees of separation simultaneously? We showed that an easy mechanism is to just have people have a very few far-flung connections. That is enough to suddenly make the world small, not just the world of people but the world of neurons in the brain or the world of power plants in the power grid. It would now take a checkerboard that's as big as eight billion people.