People tend to communicate with each other in bursts, exchanging clusters of messages over short time periods, and following these up with longer gaps in communication. But are these patterns simply the result of a tendency to talk more during the day and the working week?

Hang-Hyun Jo of Aalto University in Finland and his colleagues found that these temporal cycles are not sufficient to explain the bursts. They analysed 322 million mobile-phone calls between more than 5 million users over 119 days in 2007. After removing the effects of the day–night and working-week cycles, the bursts remained.

The authors suggest that the patterns reflect something fundamental in the way that people communicate.

N. J. Phys. 14, 013055 (2012)