Dunbar: Online social networks look like offline ones

Do online social media cut through the constraints that limit the size of offline social networks?
[Via  | Open Science]

The social brain hypothesis has suggested that natural social network sizes may have a characteristic size in humans. This is determined in part by cognitive constraints and in part by the time costs of servicing relationships. Online social networking offers the potential to break through the glass ceiling imposed by at least the second of these, potentially enabling us to maintain much larger social networks. This is tested using two separate UK surveys, each randomly stratified by age, gender and regional population size.


It’s about rapid information flow. To deal with the information glut we see, we have to move more information faster to solve problems.

Social media has not created something entirely different but has leveraged what we have to new heights.

Robin Dunbar finds that people report Facebook networks sizes peaking around 150, as seen offline. This suggests that online social netowkrs are no different than offline ones.

I’d agree but the devil is in the details.

For example, young people have much larger social networks than older people (about 250 vs 150), indicating that either Dunbar’s number is not limited or that youngsters are using Facebook in a different fashion than oldsters.

He suggests this is due to different numbers of weakly linked people. I think that is probably right and very important. Other work has shown that the most important and actionable  information does not come from close friends and family. It often comes from weakly linked people. Social media allows some to maintain much larger numbers of those, greatly increasing the flow of information.

And what if we have multiple online social networks of 150? 

Not surprised that for most people the Dunbar number does not change. On Facebook. But I suspect that the social network changes a lot looking at Twitter, at LinkedIn, at Snapchat, etc. I know mine do significantly.

The sizes may all hover around the same size but the members are quite different in each.

For example, I only found out about this paper on Facebook from Troy. Not on Twitter, not on LinkedIn, etc. My Facebook netowrk is substantially different than my Twitter.

If social media allows one to have multiple social networks of 150 (plus the offline one) then we do have something different. The size of each network may not change but having a lot more networks can accomplish the same thing.

In addition, he finds that 14% or so have much larger networks (over 300) which also fits very close to the expected number of highly connected people seen in social networks. If these people can maintain even larger networks than offline, there would be significant changes in the information flow across the network.

Finally, he finds that the similar numbers of our social hierarchy (family at 5 members and teams at 15 members) are also still seen. The structure of our online communities have not changed but the amount of information that can be exchanged is much greater.

The key thing about any network is how rapidly information moves around between people. The fewer the steps and the more reduced the friction between each step, the more rapidly information is disseminated.

Having multiple social networks, some that are much larger than previous offline ones, means that information can move exponentially faster than offline.

We do not need everyone to  have larger networks (although we do). We simply need to have the 14% who are highly connected to have much larger ones and allow information to flow faster and farther.

And information flow is the key factor for solving the complex problems facing us. Anything that hampers than is anathema. Anything that supports that is glory.

h/t Troy Camplin

Image: GustavoG