Social Network Differences of Chronotypes Identified from Mobile Phone Data

TL;DR

This study investigates how individual circadian chronotypes, identified via mobile phone data, influence social network structures and interactions among students, revealing distinct social behaviors of owls and larks.

Contribution

It introduces a novel analysis linking chronotypes to social network properties using smartphone data, highlighting differences in network size, centrality, and homophily.

Findings

Owls have larger personal networks than larks.

Owls are more central in social networks.

Owls show strong homophily in social ties.

Abstract

Human activity follows an approximately 24-hour day-night cycle, but there is significant individual variation in awake and sleep times. Individuals with circadian rhythms at the extremes can be categorized into two chronotypes: "larks", those who wake up and go to sleep early, and "owls", those who stay up and wake up late. It is well established that a person's chronotype can affect their activities and health. However, less is known on the effects of chronotypes on the social behavior, even though it is evident that social interactions require coordinated timings. To study how chronotypes relate to social behavior, we use data collected using a smartphone app on a population of more than seven hundred volunteer students to simultaneously determine their chronotypes and social network structure. We find that owls maintain larger personal networks, albeit with less time spent per contact. On average, owls are more central in the social network of students than larks, frequently occupying the dense core of the network. Owls also display strong homophily, as seen in an unexpectedly large number of social ties connecting owls to owls.