  This research explores the dynamics of emergency evacuations in the presence
of social groups. The investigation was carried out in the context of the basic
Social Force Model (SFM). We included attractive feelings between people
belonging to the same social group, as proposed in Int. J. Mod. Phys. C
27(6),1-16. We focused on the escaping dynamics through an emergency exit and
through a corridor. We confirmed the results appearing in Int. J. Mod. Phys. C
27(6),1-16 for a desired velocity of 4 m/s, but further extended the analysis
on the emergency exit to the range 1-8 m/s. We noticed that the presence of
groups worsens the evacuation performance. However, very strong feelings can
improve the escaping time with respect to moderate feelings. We call this
phenomenon "Closer-Is-Faster", in analogy to the "Faster-Is-Slower" effect. The
presence of social groups also affects the dynamic within a corridor by
introducing an additional slow-down in the moving crowd.
