We here present a model of the dynamics of extremism based on opinion
dynamics in order to understand the circumstances which favour its emergence
and development in large fractions of the general public. Our model is based on
the bounded confidence hypothesis and on the evolution of initially
anti-conformist agents to extreme positions.
Numerical analyses demonstrate that a few anti-conformists are able to drag a
large fraction of conformists agents to their position provided that they
express their views more often than the conformists. The most influential
parameter controlling the outcome of the dynamics is the uncertainty of the
conformist agents; the higher their uncertainty, the higher is the influence of
anti-conformists. Systematic scans of the parameter space show the existence of
two regime transitions, one following the conformists uncertainty parameter and
the other one following the anti-conformism strength.Comment: 37 pages, 20 figures, fortran demo progra