It was interesting to note that the word of 2009 was ‘Unfriending.’

Are we finally waking up to the fact that when it comes to friendship it’s quality not quantity that counts? My friend Matt recently sent me a note about something called Dunbar’s number. This is a theoretical cognitive limit to the number of friends that one can realistically have. How large is this number? I was rather surprised to find out that it’s somewhere between 100 and 230, with 150 being a commonly agreed figure.

This seems too high to me, although the average number of confirmed friends people have on Facebook is 120, while a few years ago the average number of contacts (not friends) on linkedin was 60.

Clearly there is a big difference between digital and physical friends, although I’d be really interested to know what the crossover is. What percentage of these 120 friends do Facebook users see in person and how often? It would also be interesting to research the definition of ‘friend’. Interestingly, a University of Arizona study recently found that 25% of Americans have no really close friends at all (friend being defined here as someone that you can talk to about your deepest hopes and fears).

Ref: http://en.wikipedia.org/wiki/Dunbar%27s_number