  Understanding the social conditions that tend to increase or decrease
polarization is important for many reasons. We study a network-structured
agent-based model of opinion dynamics, extending a model previously introduced
by Flache and Macy (2011), who found that polarization appeared to increased
with the introduction of long-range ties but decrease with the number of
salient opinions, which they called the population's "cultural complexity." We
find the following. First, polarization is strongly path dependent and
sensitive to stochastic variation. Second, polarization depends strongly on the
initial distribution of opinions in the population. In the absence of
extremists, polarization may be mitigated. Third, noisy communication can drive
a population toward more extreme opinions and even cause acute polarization.
Finally, the apparent reduction in polarization under increased "cultural
complexity" arises via a particular property of the polarization measurement,
under which a population containing a wider diversity of extreme views is
deemed less polarized. This work has implications for understanding the
population dynamics of beliefs, opinions, and polarization, as well as broader
implications for the analysis of agent-based models of social phenomena.
