Behavioral Studies Colloquium Spring 2015
April 21, 2015
Speaker:
Prof. Dr. Andreas Flache, Department of Sociology – ICS,
University of Groningen, The Netherlands (hosted by
Professor Dirk Helbing):
Title:
Negative social influence and the fragility of pluriformity in opinion formation.
Abstract: Opinion distributions in a group are often characterized by pluriformity, clustering in subgroups with consensus within and disagreement between the subgroups.
Stable pluriformity is difficult to explain for models of opinion formation building on social
influence, the empirically well-supported tendency of people to move closer to the
opinions of influential others. They typically predict a tendency towards global consensus.
In the present paper, it is analyzed whether and under what conditions pluriformity can
be explained by incorporating negative social influence, the tendency to increase opinion
differences with highly dissimilar others. Previous work mainly focused on how such a
model entails bi-polarization – a split into two extremely opposed factions. In this paper
it is shown how also pluriformity is possible, but only under highly restrictive conditions
and as a highly fragile state. For a simple case analytical results are presented. Then
more complex situations are analyzed with computational modelling, focusing on
complexities that arise from demographic differences between subgroups and their
spatial segregation. In contradiction with an intuition often echoed in the literature,
models imply that spatial segregation may reduce bi-polarization and foster pluriformity.