Thursday, 5 April 2007
Want to know whether your network of friends will survive or break up? Try mathematics, researchers say.
They’ve been looking at social interaction in the complex, fast-moving world of online social networks and people’s mobile phone contacts.
They’ve come up with an alogorithm to explain it all, which they publish today in the journal Nature.
Professor Tamas Vicsek of Budapest’s Eotvos Lorand University and colleagues trawled through two sets of data to explore how people link up.
One was a collaborative network of more than 30,000 researchers connected to an archive at New York’s Cornell University; the other was the year-long record of communications patterns of 4 million mobile phone users.
Put together, these figures provided an intriguing picture of relationship dynamics.
The Hungarian and US team found that small groups only last if they have an unchanged core of members, in other words, a clique.
“A typically small and stationary community undergoes minor changes, but lives for a long time,” the researchers report.
But among large groups, the opposite holds true.
A large community breaks up quickly if it is stationary, but endures if it opens itself up to new members. Over time, nearly all members are exchanged.
One example of this successful, loose affiliation is a school or a company.
In a few years, most members or employees may change, yet the entity will be detectable as a “distinct community” at any time during its existence, says the study.
Vicsek’s group also developed a complex formula based on a group member’s contacts with others, to predict whether that individual would stay with the group or leave it.
The figures bear out, mathematically, what we know instinctively.
Someone who shows a heightened interest in an outside group is probably about to leave the present one and the more contact the present group has with the member, the more likely he or she is committed to staying.