Limited communication capacity unveils strategies for human interaction

TL;DR

This study reveals that humans have a finite communication capacity influencing social tie dynamics, with differences across gender and age, and demonstrates how interaction strategies affect information spread in social networks.

Contribution

Developed a method to detect tie activation/deactivation, revealing finite communication capacity and diverse interaction strategies in large-scale human communication data.

Findings

Individuals have a limited communication capacity.

Men generally have higher capacity than women.

Exploratory strategies delay information spread.

Abstract

Social connectivity is the key process that characterizes the structural properties of social networks and in turn processes such as navigation, influence or information diffusion. Since time, attention and cognition are inelastic resources, humans should have a predefined strategy to manage their social interactions over time. However, the limited observational length of existing human interaction datasets, together with the bursty nature of dyadic communications have hampered the observation of tie dynamics in social networks. Here we develop a method for the detection of tie activation/deactivation, and apply it to a large longitudinal, cross-sectional communication dataset ($\approx$ 19 months, $\approx$ 20 million people). Contrary to the perception of ever-growing connectivity, we observe that individuals exhibit a finite communication capacity, which limits the number of ties they can maintain active. In particular we find that men have an overall higher communication capacity than women and that this capacity decreases gradually for both sexes over the lifespan of individuals (16-70 years). We are then able to separate communication capacity from communication activity, revealing a diverse range of tie activation patterns, from stable to exploratory. We find that, in simulation, individuals exhibiting exploratory strategies display longer time to receive information spreading in the network those individuals with stable strategies. Our principled method to determine the communication capacity of an individual allows us to quantify how strategies for human interaction shape the dynamical evolution of social networks.