Understanding the Heavy Tailed Dynamics in Human Behavior

TL;DR

This paper investigates the origins of heavy tailed inter-event times in human communication, testing competing hypotheses with social media data, and proposes a new model that better explains the underlying mechanisms.

Contribution

It provides evidence that residual heavy tails are not fully explained by circadian and burstiness effects, introducing a novel model for human interaction dynamics.

Findings

Models with circadian rhythms and burstiness explain part of the heavy tails.

Residual heavy tail behavior suggests a more fundamental cause.

The new model improves understanding of human interaction mechanisms.

Abstract

The recent availability of electronic datasets containing large volumes of communication data has made it possible to study human behavior on a larger scale than ever before. From this, it has been discovered that across a diverse range of data sets, the inter-event times between consecutive communication events obey heavy tailed power law dynamics. Explaining this has proved controversial, and two distinct hypotheses have emerged. The first holds that these power laws are fundamental, and arise from the mechanisms such as priority queuing that humans use to schedule tasks. The second holds that they are a statistical artifact which only occur in aggregated data when features such as circadian rhythms and burstiness are ignored. We use a large social media data set to test these hypotheses, and find that although models that incorporate circadian rhythms and burstiness do explain part of the observed heavy tails, there is residual unexplained heavy tail behavior which suggests a more fundamental cause. Based on this, we develop a new quantitative model of human behavior which improves on existing approaches, and gives insight into the mechanisms underlying human interactions.