New activity pattern in human interactive dynamics

TL;DR

This paper uncovers a universal heavy-tailed response time distribution pattern in human email correspondence, showing exponential growth of response times with contact rank, and demonstrates its robustness through a prioritization model.

Contribution

It reveals a universal response time distribution pattern in human communication and shows its emergence from a basic prioritization model, advancing understanding of reactive dynamics.

Findings

Response times follow heavy-tailed distributions across contacts.

Characteristic response times grow exponentially with contact rank.

The pattern is robust under a priority-based response model.

Abstract

We investigate the response function of human agents as demonstrated by written correspondence, uncovering a new universal pattern for how the reactive dynamics of individuals is distributed across the set of each agent's contacts. In long-term empirical data on email, we find that the set of response times considered separately for the messages to each different correspondent of a given writer, generate a family of heavy-tailed distributions, which have largely the same features for all agents, and whose characteristic times grow exponentially with the rank of each correspondent. We furthermore show that this universal behavioral pattern emerges robustly by considering weighted moving averages of the priority-conditioned response-time probabilities generated by a basic prioritization model. Our findings clarify how the range of priorities in the inputs from one's environment underpin and shape the dynamics of agents embedded in a net of reactive relations. These newly revealed activity patterns might be present in other general interactive environments, and constrain future models of communication and interaction networks, affecting their architecture and evolution.