Emergence of segregation in evolving social networks

Abstract

In many social networks, there is a high correlation between the similarity of actors and the existence of relationships between them. This paper introduces a model of network evolution where actors are assumed to have a small aversion from being connected to others who are dissimilar to themselves, and yet no actor strictly prefers a segregated network. This model is motivated by Schelling's [Schelling TC (1969) Models of segregation. Am Econ Rev 59:488-493] classic model of residential segregation, and we show that Schelling's results also apply to the structure of networks; namely, segregated networks always emerge regardless of the level of aversion. In addition, we prove analytically that attribute similarity among connected network actors always reaches a stationary distribution, and this distribution is independent of network topology and the level of aversion bias. This research provides a basis for more complex models of social interaction that are driven in part by the underlying attributes of network actors and helps advance our understanding of why dysfunctional social network structures may emerge. The Problem of Segregation in Social NetworksCooperation and conflict in social networks are central features of many contemporary social and policy issues, including commons governance, climate change policy, and economic development. Of particular importance is the well-known tendency for network linkages to concentrate between actors who are similar to one another in terms of certain key attributes-a phenomenon we refer to as "attribute closeness." Attribute closeness is one important indicator of segregation within a social network, as it signals tightly knit communities of homogenous actors and may reinforce divisions between disparate groups. These types of networks have been observed in a wide variety of contexts (1-3), including diverse examples such as race-and gender-oriented segregation in high school friendship networks and value-and belief-oriented segregation in environmental policy networks. Thus, the literature provides many empirical examples of segregation in terms of the structure of relationships, in addition to the geographically explicit residential segregation studied in Schelling's classic model of this phenomenon (4, 5).Network segregation is problematic when actors are faced with the need to collectively address complex social, environmental, or economic dilemmas. For example, social and policy networks are an important part of the machinery of collective action (6, 7). If the networks that form around social dilemmas are heavily fragmented, then it may be difficult for actors to develop the social capital necessary for the emergence of cooperative behavior (8). These fragmentations are observed in real-world policy networks, such as in regional planning networks where segregation is often observed between actors working in different functional domains (e.g., when transportation planners fail to coordinate with landuse planners), levels of government (e.g., when federal agencies ...

Bringing values and deliberation to science communication

“…That, in turn, makes it difficult to develop sound policy (53). We also know that in social networks, even relatively modest preferences to associate with similar people and avoid dissimilar people can have substantial effects on how network structure evolves (54).…”

Graph fission in an evolving voter model

“…Networks that exhibit such a feedback are called adaptive or coevolutionary networks (19,20). As in the case of static networks, significant attention has been paid to evolutionary games (21)(22)(23)(24) and to the spread of epidemics (25-29) and opinions (30-35), including the polarization of a network of opinions into two groups (36,37). In this paper, we examine two closely related variants of a simple, abstract model for coevolution of a network and the opinions of its members.…”

Role of social environment and social clustering in spread of opinions in coevolving networks

“…Several analytical and simulation results have been obtained following Schelling's model on networks as well as on coevolving networks but not in the context of modeling processes involved in collective opinion formation. [36][37][38] A visualization for these observations for N ¼ 1000 nodes with O ¼ 100 is shown in Fig. 2.…”