Geographic constraints on social network groups

TL;DR

This study analyzes how geographic constraints influence social network group structures, revealing that small groups are geographically tight, but larger groups become more dispersed, with no correlation between social and geographic positions.

Contribution

It provides empirical evidence on the relationship between geography and social group structure using real-world social network data.

Findings

Small groups are geographically tight.

Groups larger than 30 members are more geographically dispersed.

No correlation between topological and geographic positions within groups.

Abstract

Social groups are fundamental building blocks of human societies. While our social interactions have always been constrained by geography, it has been impossible, due to practical difficulties, to evaluate the nature of this restriction on social group structure. We construct a social network of individuals whose most frequent geographical locations are also known. We also classify the individuals into groups according to a community detection algorithm. We study the variation of geographical span for social groups of varying sizes, and explore the relationship between topological positions and geographic positions of their members. We find that small social groups are geographically very tight, but become much more clumped when the group size exceeds about 30 members. Also, we find no correlation between the topological positions and geographic positions of individuals within network communities. These results suggest that spreading processes face distinct structural and spatial constraints.