Strategies in crowd and crowd structure
  In an emergency situation, imitation of strategies of neighbours can lead to an order-disorder phase transition, where spatial clusters of pedestrians adopt the same strategy. We assume that there are two strategies, cooperating and competitive, which correspond to a smaller or larger desired velocity. The results of our simulations within the Social Force Model indicate that the ordered phase can be detected as an increase of spatial order of positions of the pedestrians in the crowd. 
P. Gawronski, K. Malarz, M. J. Krawczyk, J. Malinowski, A. Kupczak, W.   Sikora, K. Kulakowski, J. Was and J. Kantelhardt
physics.soc-ph cs.SI nlin.CD