Rumor propagation meets skepticism: A parallel with zombies

¹ Instituto de Física, Universidade Federal do Rio Grande do Sul - CP 15051 91501-970, Porto Alegre, RS, Brazil
² Universidade Federal do Sul da Bahia - 45988, Praça Joana Angélica 58 São José, Teixeira de Freitas, BA, Brazil

^(a) marcoantonio.amaral@gmail.com
^(b) arenzon@if.ufrgs.br

Received: 4 August 2018
Accepted: 5 October 2018

Abstract

We propose a model of rumor spreading in which susceptible, but skeptically oriented individuals may oppose the rumor. Resistance may be implemented either by skeptical activists trying to convince spreaders to stop their activity, becoming stiflers or, passively (non-reactive) as a consequence, for example, of fact-checking. Interestingly, these two mechanisms, when combined, are similar to the (assumed) spreading of a fictitious zombie outbreak, where survivors actively target infected people. We analyse the well-mixed (mean-field) description and obtain the conditions for rumors (zombies) to spread through the whole population. The results show that when the skepticism is strong enough, the model predicts the coexistence of two fixed points (such bistability may be related to polarized situations), with the fate of rumors depending on the initial exposure to it.