Title: Twitter and the Press: an Ego-Centred Analysis,
Abstract: Ego networks have proved to be a valuable tool for understanding the
relationships that individuals establish with their peers, both in offline and
online social networks. Particularly interesting are the cognitive constraints
associated with the interactions between the ego and the members of their ego
network, whereby individuals cannot maintain meaningful interactions with more
than 150 people, on average. In this work, we focus on the ego networks of
journalists on Twitter, and we investigate whether they feature the same
characteristics observed for other relevant classes of Twitter users, like
politicians and generic users. Our findings are that journalists are generally
more active and interact with more people than generic users. Their ego network
structure is very aligned with reference models derived from the social brain
hypothesis and observed in general human ego networks. Remarkably, the
similarity is even higher than the one of politicians and generic users ego
networks. This may imply a greater cognitive involvement with Twitter than with
other social interaction means. Moreover, the ego networks of journalists are
much stabler than those of politicians and generic users, and the ego-alter
ties are often information-driven.