Synchronising institutions and value systems: A model of opinion dynamics mediated by proportional representation

Abstract

Individuals increasingly participate in online platforms where they copy, share and form they opinions. Social interactions in these platforms are mediated by digital institutions, which dictate algorithms that in turn affect how users form and evolve their opinions. In this work, we examine the conditions under which convergence on shared opinions can be obtained in a social network where connected agents repeatedly update their normalised cardinal preferences (i.e. value systems) under the influence of a non-constant reflexive signal (i.e. institution) that aggregates populations’ information using a proportional representation rule. We analyse the impact of institutions that aggregate (i) expressed opinions (i.e. opinion-aggregation institutions), and (ii) cardinal preferences (i.e. value-aggregation institutions). We find that, in certain regions of the parameter space, moderate institutional influence can lead to moderate consensus and strong institutional influence can lead to polarisation. In our randomised network, local coordination alone in the total absence of institutions does not lead to convergence on shared opinions, but very low levels of institutional influence are sufficient to generate a feedback loop that favours global conventions. We also show that opinion-aggregation may act as a catalyst for value change and convergence. When applied to digital institutions, we show that the best mechanism to avoid extremism is to increase the initial diversity of the value systems in the population.

Cultural evolution: A review of theoretical challenges

“…Recent formal developments enabling the combination of micro- and macro-models are allowing modellers to meet this need and, consequently, they will stimulate high-quality research in CES and assist in overcoming challenge (C3). Micro- and macro-models can be combined by building adaptive dynamics models or with multilevel selection models where both events at the individual level generate effects at the group level and events at the group level affect the individual properties of the system (Mullon & Lehmann, 2017 ; Fishwick, 1995 ; McElreath & Henrich, 2007 ; Waring et al, 2017 ; Segovia-Martin & Tamariz, 2021 ). This represents the future of modelling in cultural evolution, but it is not itself without challenges.…”

Modelling the dynamics of cross-border ideological competition

“…Existing models of ideology dynamics have focused on the transmission and evolution of political ideas within a single voting population [1,2,3,4,5,6,7]. In contrast, the model we describe here idealises ideologies as fixed and as competing with each other for supporters both within and across borders.…”

Cross-border political competition

“…More recently, opinion dynamics models have been used to explore the dynamics of competing opinions by taking into account the interactions between agents [24][25][26][27]. These models span from simplistic binary systems such as the voter model [24,28] to more complex multidimensional continuous frameworks [29].…”

“…These models span from simplistic binary systems such as the voter model [24,28] to more complex multidimensional continuous frameworks [29]. They predominantly simulate two primary sources of influence: peer influence, defined as the direct impact of social peers [30][31][32], and external influence [27,33], which encompasses broader societal pressures such as of institutions [25] propaganda [34], fashion [35,36], or the mass media [37][38][39]. Particularly relevant to the work we present here is the model of opinion dynamics proposed by Dan Braha and M de Aguilar [40], which suggests that social influence and contagion are likely to intensify as societies become increasingly interconnected through the widespread availability of digital communication and transportation networks.…”