Earlier, I mused about whether the inherent limit on human interaction group size would apply to online social networks or not. That limit is called “Dunbar’s Number” and is estimated to be ~150, based on observations of social networks among primates and then extrapolating to humans taking increased brainpower into consideration. An intriguing piece in the WSJ asks whether online social networks are still bound by Dunbar’s number or whether technological innovation might permit us to exceed it:
But there is reason to believe that the social-networking sites will enable their users to burst past Dunbar’s number for friends, just as humans have developed and harnessed technology to surpass their physical limits on speed, strength and the ability to process information.
Robin Dunbar, an Oxford anthropologist whose 1993 research gave rise to the magical count of 150, doesn’t use social-networking sites himself. But he says they could “in principle” allow users to push past the limit. “It’s perfectly possible that the technology will increase your memory capacity,” he says.
The question is whether those who keep ties to hundreds of people do so to the detriment of their closest relationships — defined by Prof. Dunbar as those formed with people you turn to when in severe distress.
The problem here is the definition of the word “relationship”. Dunbar’s definition of “closest” is just one of many possible ones, and the various definitions might well overlap. But does that mean that business relationships are excluded from Dunbar’s limit? If so, then you might expect to see many more contacts on LinkedIn, which caters to a business networking model, than on Facebook which is primarily stalker heaven. LinkedIn is approaching critical mass in terms of network effect; RWW found over 80% of their business contacts already using it, for example.
There are surely other models one could employ to map relationships: blogrolls, chat client lists, twitter fans/friends, etc. I think any one of these – or a weighted combination of all of them – would be good data sets to see whether Dunbar’s number truly holds online or not.