The Physics of Friendship
Fascinating! While I imagine that this approach may not appeal to some "idealist" students of human interaction, I think it's an interesting model. Obviously it doesn't say much about the individual "particle's" motivation and such, but as long as you look at clusters of particles, motivation is not really that important, unless it shows in a class of behaviour that can be generalised. A case in point might be the alleged differences in sexual and social contact networks.