Gaslike model of social motility
  We propose a model to represent the motility of social elements. The model is completely deterministic, possesses a small number of parameters, and exhibits a series of properties that are reminiscent of the behavior of comunities in social-ecological competition; these are: (i) similar individuals attract each other; (ii) individuals can form stable groups; (iii) a group of similar individuals breaks into subgroups if it reaches a critical size; (iv) interaction between groups can modify the distribution of the elements as a result of fusion, fission, or pursuit; (v) individuals can change their internal state by interaction with their neighbors. The simplicity of the model and its richness of emergent behaviors, such as, for example, pursuit between groups, make it a useful toy model to explore a diversity of situations by changing the rule by which the internal state of individuals is modified by the interactions with the environment. 
A. Parravano and L. M. Reyes