  Mexican wave, or La Ola, first widely broadcasted during the 1986 World Cup
held in Mexico, is a human wave moving along the stands of stadiums as one
section of spectators stands up, arms lifting, then sits down as the next
section does the same. Here we use variants of models originally developed for
the description of excitable media to demonstrate that this collective human
behaviour can be quantitatively interpreted by methods of statistical physics.
Adequate modelling of reactions to triggering attempts provides a deeper
insight into the mechanisms by which a crowd can be stimulated to execute a
particular pattern of behaviour and represents a possible tool of control
during events involving excited groups of people.
