Validation of Dunbar's number in Twitter conversations

TL;DR

This study analyzes Twitter conversations over six months involving 1.7 million users to empirically validate Dunbar's number, confirming a cognitive limit of 100-200 stable relationships online.

Contribution

The paper provides large-scale empirical evidence supporting Dunbar's number in online social interactions and introduces a simple dynamical model explaining this limit.

Findings

Users maintain 100-200 stable relationships on Twitter.

The online attention economy is constrained by cognitive limits.

A dynamical model reproduces observed social behavior.

Abstract

Modern society's increasing dependency on online tools for both work and recreation opens up unique opportunities for the study of social interactions. A large survey of online exchanges or conversations on Twitter, collected across six months involving 1.7 million individuals is presented here. We test the theoretical cognitive limit on the number of stable social relationships known as Dunbar's number. We find that users can entertain a maximum of 100-200 stable relationships in support for Dunbar's prediction. The "economy of attention" is limited in the online world by cognitive and biological constraints as predicted by Dunbar's theory. Inspired by this empirical evidence we propose a simple dynamical mechanism, based on finite priority queuing and time resources, that reproduces the observed social behavior.