Particle creation should probably have a tendency to occur near other particles.

(slightly) viscous medium makes sense though, maybe.

I'm not sure the model should have stable equilibriums. ie, I'm not sure the way people actually behave is such that a model with stable equilibriums would actually accurately reflect reality. In real life, attitudes change over time, no? So do we really want to select/reject models based on whether or not there are stable equilibria? We should probably expect states that are stable...ish. That is, chunks of the system that are slow to change.