Public and private beliefs under disinformation in social networks

TL;DR

This paper models how social network agents form beliefs about the truth, highlighting the impact of disinformation and conspiracy spread on consensus and dissonance, and explores mitigation strategies.

Contribution

It introduces a novel opinion dynamics model incorporating disinformation agents and analyzes their effects on belief convergence and cognitive dissonance.

Findings

Disinformation agents cause peak dissonance at small minority levels.

Presence of debunkers reduces dissonance but does not eliminate it.

Model explains phenomena similar to cognitive dissonance in social networks.

Abstract

We develop a model of opinion dynamics where agents in a social network seek to learn a ground truth among a set of competing hypotheses. Agents in the network form private beliefs about such hypotheses by aggregating their neighbors' publicly stated beliefs, in an iterative fashion. This process allows us to keep track of scenarios where private and public beliefs align, leading to population-wide consensus on the ground truth, as well as scenarios where the two sets of beliefs fail to converge. The latter scenario - which is reminiscent of the phenomenon of cognitive dissonance - is induced by injecting 'conspirators' in the network, i.e., agents who actively spread disinformation by not communicating accurately their private beliefs. We show that the agents' cognitive dissonance non-trivially reaches its peak when conspirators are a relatively small minority of the population, and that such an effect can be mitigated - although not erased - by the presence of 'debunker' agents in the network.