thoughts on changing technologies

The Network Effect, or Metcalfe’s Law, states that the value of a communications network is proportional to the square of the number of its users. Here’ Bob Metcalfe’s original slide illustrating that fact:

Whether or not it is correct, Metcalfe’s Law illustrates the value of the Network Effect, that the more people, devices and IP-aware vacuum cleaners there are on the “network”, the better. Heck, that’s been the assumption we’ve always used to justify the expansion of communications networks for ages.

You’d think Metcalfe’s Law would also apply to social networks, ie the more “friends” you have on your social network the more rich and complete your life is. Apparently that’s not the case. According the Dunbar Number, the maximum number of stable relationships us humans can have is 150. Any more and things would go quite wobbly. From the Economist:

Primatologists call at least some of the things that happen on social networks “grooming”. In the wild, grooming is time-consuming and here computerisation certainly helps. But keeping track of who to groom—and why—demands quite a bit of mental computation. You need to remember who is allied with, hostile to, or lusts after whom, and act accordingly. Several years ago, therefore, Robin Dunbar, an anthropologist who now works at Oxford University, concluded that the cognitive power of the brain limits the size of the social network that an individual of any given species can develop. Extrapolating from the brain sizes and social networks of apes, Dr Dunbar suggested that the size of the human brain allows stable networks of about 148. Rounded to 150, this has become famous as “the Dunbar number”.

Facebook reports that the average number of “friends” subscribers have is 120, corresponding closely to the Dunbar number. However, they also note that the size of the real social network is actually quite smaller, with men responding with any frequency to only seven of those friends online, and women responding to only 10. Having 500 friends doesn’t seem to increase things much either.

The upshot of all this is twofold. Thankfully, the amount of FB “friends” you have is not really related to your Dunbar-150 and that social networks are really more of broadcasting than networking medium. The network effects of your “friends” beyond  a handful is very limited. Frankly, I find this a relief.