The fragility of opinion formation in a complex world

TL;DR

This paper investigates how complex networks of trust and distrust influence opinion formation, revealing that opinions tend to be inconsistent and unstable, especially as complexity increases, unless initial information is sufficiently expanded.

Contribution

It introduces a model of opinion formation on signed networks and analytically demonstrates the effects of network complexity on opinion stability and consistency.

Findings

Opinions are highly inconsistent and unstable in complex trust/distrust networks.

Increasing initial information reduces opinion inconsistency and instability.

Trust relations between credible and deceptive sources can lead to false beliefs.

Abstract

With vast amounts of high-quality information at our fingertips, how is it possible that many people believe that the Earth is flat and vaccination harmful? Motivated by this question, we quantify the implications of an opinion formation mechanism whereby an uninformed observer gradually forms opinions about a world composed of subjects interrelated by a signed network of mutual trust and distrust. We show numerically and analytically that the observer's resulting opinions are highly inconsistent (they tend to be independent of the observer's initial opinions) and unstable (they exhibit wide stochastic variations). Opinion inconsistency and instability increase with the world complexity represented by the number of subjects, which can be prevented by suitably expanding the observer's initial amount of information. Our findings imply that even an individual who initially trusts credible information sources may end up trusting the deceptive ones if at least a small number of trust relations exist between the credible and deceptive sources.