This preprint interrogates the concept of “six degrees of separation,” which postulates that, within a social network, no one person is removed from any other by more than six steps. But is this the case? And if so, mathematically, why would this hold true? The authors propose that “six degrees of separation” constitutes the “equilibrium state of any network where individuals weigh between their aspiration to improve their centrality and the costs incurred in forming and maintaining connections.”

See the full list of authors and read their research, “Why are there six degrees of separation in a social network?” at ArXiv.