Modeling Echo Chambers and Polarization Dynamics in Social Networks

Abstract

Echo chambers and opinion polarization have been recently quantified in several sociopolitical contexts, across different social media, raising concerns for the potential impact on the spread of misinformation and the openness of debates. Despite increasing efforts, the dynamics leading to the emergence of these phenomena remain unclear. Here, we propose a model that introduces the phenomenon of radicalization, as a reinforcing mechanism driving the evolution to extreme opinions from moderate initial conditions. Empirically inspired by the dynamics of social interaction, we consider agents characterized by heterogeneous activities and homophily. We analytically characterize the transition between a global consensus and emerging radicalization dynamics in the population, as a function of social influence and the controversialness of the topic discussed. We contrast the model's behavior against empirical data of polarized debates on Twitter, qualitatively reproducing the observed relation between users' engagement and opinions, as well as opinion segregation based on the interaction network. Our findings shed light on the dynamics that may lie at the core of the emergence of echo chambers and polarization in social media.

Social influence and unfollowing accelerate the emergence of echo chambers

“…Network transitivity, which is also incorporated in our model, has been shown to lead to the formation of groups when combined with reciprocity [66] or with one-to-many communication [67]. Pressures toward stronger opinions [68] or more radical opinions [69] are not included in our model, nor are repulsion effects driving opinions farther apart [13,55]. Echo chambers can also emerge from cognitive mechanisms, such as confirmation bias, when information propagates through centralized channels reaching a large portion of the population [70].…”

How behavioural sciences can promote truth, autonomy and democratic discourse online

“…Super-sports @sportsbrand -Sep 9 Follow your dream and reach new goals with our products. network 88,89 can create the illusion of broad support 90 and reinforce opinions or even make them more extreme 91,92 . For instance, even if only a tiny fraction (for example, one in a million) of the more than two billion Facebook users believe that the Earth is flat, they could still form an online community of thousands, thereby creating a shield of like-minded people against corrective efforts [93][94][95][96] .…”

Dynamics of opinion expression

“…After having solved Eqs. (33) and (32) for Q 1 and Q 2 , we can assess the stability of the respective fixed points by calculating the eigenvalues of their Jacobian; two negative (real parts of the) eigenvalues indicate a stable attractor. In the following, we analyze the bifurcation structure of the system depending on the different types of parameters in the system.…”

“…We then arrive at a structure similar to "echo chambers," in which only the voices affirming one's own view are heard and the others are blocked out (see Ref. [33] for a contribution linking opinion dynamics to the emergence of echo chambers). If the additional connections are made between the opinion blocks, then both γ and δ decrease, which might make it more probable that the individuals have a more realistic picture of the overall opinion landscape.…”