Dunbar’s number is the name given to a theoretical limit on the number of people one can maintain long-term stable relationships. This number has previously been pegged at values around one or two hundred. In this era of social networking, given that the number of on-line “friends” we have can run into several hundred if not thousands, it’s easy to believe that technology, through external cognition, has helped us overcome cognitive limits imposed by the zombie food sloshing around our skulls. Except it probably hasn’t.
Here’s a thought experiment I often ponder: What if social networking sites like Facedbook [sic] started limiting users to 200 friends? ((This is a thought experiment for me not only because I doubt F***book would ever do this — exploiting your “friends” for advertising dollars is too lucrative — but also because I don’t use the site.)) Who would you keep in your contact list? Who would keep you? Would people be more selective to begin with in adding contacts so as to avoid the faux pas of “de-friending” later?
There was a paper at the 2008 Internet measurement conference from KAIST about this. They found that when you look at graphs of interactions in online social networks (vs the static friendship graph) Dunbar’s number holds.