  We analyze the dynamics of room evacuation for mixed populations that include
both competitive and cooperative individuals through numerical simulations
using the social force model. Cooperative agents represent well-trained
individuals who know how to behave in order to reduce risks within high-density
crowds. We consider that competitive agents can imitate cooperative behavior
when they are in close proximity to cooperators. We study the effects of the
imitation of cooperative behavior on the duration and safety of evacuations,
analyzing evacuation time and other quantities of interest for varying
parameters such as the proportions of mixing, the aspect ratio of the room, and
the parameters characterizing individual behaviors. Our main findings reveal
that the addition of a relatively small number of cooperative agents into a
crowd can reduce evacuation time and the density near the exit door, making the
evacuation faster and safer despite an increase in the total number of agents.
In particular, for long spaces such as corridors, a small number of added
cooperative agents can significantly facilitate the evacuation process. We
compare our results with those of systems without imitation and also study the
general role of cooperation, providing further analysis for homogeneous
populations. Our main conclusions emphasize the potential relevance of training
people how to behave in high-density crowds
