Identifying and modeling patterns of human activity has important ramifications in applications ranging from predicting disease spread to optimizing resource allocation. Because of its relevance and availability, written correspondence provides a powerful proxy for studying human activity. One school of thought is that human correspondence is driven by responses to received correspondence, a view that requires distinct response mechanism to explain e-mail and letter correspondence observations. Here, we demonstrate that, like e-mail correspondence, the letter correspondence patterns of 16 writers, performers, politicians, and scientists are well-described by the circadian cycle, task repetition and changing communication needs. We confirm the universality of these mechanisms by properly rescaling letter and e-mail correspondence statistics to reveal their underlying similarity.
@article{arxiv.0909.4724,
title = {On Universality in Human Correspondence Activity},
author = {R. Dean Malmgren and Daniel B. Stouffer and Andriana S. L. O. Campanharo and Luis A. Nunes Amaral},
journal= {arXiv preprint arXiv:0909.4724},
year = {2009}
}