The Physics of Friendship: Do we make friendships no differently than a bunch of particles bouncing around?

Here's an interesting article that I came across that surveyed 90,000 high school students to reconstruct friendship networks and then created a model of the results using knowledge of how particles in physical systems collide and interact. Haven't read the article in depth so I'm not really doing much of a job in terms of useful commentary on its merits. Just pointing it out. (The lead author on the paper though is Marta Gonzales who worked with Albert Laszlo Barabasi who wrote Linked that I posted on earlier).

The Physics of Friendship (This is an easy to read writeup on the actual paper)
By comparing people to mobile particles randomly bouncing off each other, scientists have developed a new model for social networks. The model fits with empirical data to naturally reproduce the community structure, clustering and evolution of general acquaintances and even sexual contacts.

The paper is also an example of how you can use surveys to reconstruct networks and dynamics, relevant to my previous post 'Where does the money go?' and the discussion around it. It would be interesting to see how such social networks in small villages differ from those in large cities particularly with respect to trade (as opposed to friendships). Could be quite telling about how our microentrepreneurs do business since how they bump into each other would be totally different from the way we technology enabled urban folk do.