Degree distributions of the empirical datasets.

<p>In panels A–D, we plot the probability density <i>p</i> as a function of degree <i>k</i>. We plot results both for the accumulated network of all contacts and averages of three networks of ongoing contacts (defined by all edges that, at a certain time <i>t′</i>, a contact over all edges have happened and will happen again). We choose <i>t′</i> as when a quarter, half and three quarter have happened. In panel E, we show the values of two types of temporal statistics of the datasets—the persistence (which separates the e-mail data from the rest) and burstiness.