Opinion dynamics and wisdom under out-group discrimination

TL;DR

This paper introduces a DeGroot-like opinion dynamics model incorporating opposition between agents, explaining persistent disagreement and polarization based on network structure and opposition modes, with implications for social influence and wisdom.

Contribution

It develops a novel opinion dynamics framework with opposition, deriving conditions for polarization and analyzing the impact of negative relations on collective wisdom.

Findings

Long-run polarization depends on network structure and opposition mode.

Certain opposition functions lead to persistent disagreement.

Strong negative relations hinder collective wisdom.

Abstract

We study a DeGroot-like opinion dynamics model in which agents may oppose other agents. As an underlying motivation, in our setup, agents want to adjust their opinions to match those of the agents of their 'in-group' and, in addition, they want to adjust their opinions to match the 'inverse' of those of the agents of their 'out-group'. Our paradigm can account for persistent disagreement in connected societies as well as bi- and multi-polarization. Outcomes depend upon network structure and the choice of deviation function modeling the mode of opposition between agents. For a particular choice of deviation function, which we call soft opposition, we derive necessary and sufficient conditions for long-run polarization. We also consider social influence (who are the opinion leaders in the network?) as well as the question of wisdom in our naive learning paradigm, finding that wisdom is difficult to attain when there exist sufficiently strong negative relations between agents.