Large city, small town – human social networks are very similar but can carry very different information loads

Even in large cities, we build tightly-knit communities
[Via Boing Boing]

A study of group clustering–do your friends know each other?–shows that it does not change with city size. [via Flowing Data]



An average person in the small town (population – 4233) has 6 connections who have a 25% chance of knowing each other. In a large town (population – 564.657), the number of friends is 11 but the chance that they will know each other remains 25%.

This fits a lot of previous data – the majority of any community connect with one another to a very high degree. The difference between living in a large city or a small town lies in how big the network is, not in its shape.

And, it shows that the size of the network increases faster than the size of the community. Not only are there more people to connect to in a large city. People in a large city connect to more people than those in smaller groups.

But the chance that those people know each other remains about the same. That is, the structure of the social network does not change. No matter the size of the town or the size of the network, about 25% of the people will know each other.

city size.png

Interestingly, as the size of the town increases, the networks get larger, and people make contact with other people in the networks more often. So not only are the networks scaling ‘linearly’ but the total number of contacts increases super-linearly.

If we look at the total cumulative calls made, we see that more calls are made to more people in large towns than in small towns. 


What they were then able to show in the paper is that because of the types of connections seen in bigger cities, information spreads much more rapidly here than in smaller communities.

In a world dealing with rapidly changing environments and increasingly more complex problems, the ability to move information around rapidly so as to create knowledge and wisdom becomes critical.

But it also shows that people in large cities are not isolated at all but maintain rich connections with others. We live in communities that are about as tightly knit in large cities as in smaller ones. They are just larger.