All Commentary
Tuesday, November 29, 2011

Facebook and Familiar Strangers

Great societies and little platoons.


Right now, how many people do you know and keep in contact with? How many names are on your Rolodex, or friends do you have on Facebook? And how many people can you recognize whose names you don’t know? For most of us the answers get bigger with each question.

Stop to think about it. Depending on where you live, you may see hundreds or thousands of people each month – from neighbors and coworkers to store clerks and customers – whom you recognize but rarely interact with.  My guess would be that the smaller the town you live in, the more such people you’re likely to see because there’s a bigger chance of running into them again and again. These are sociologist Stanley Milgram’s “familiar strangers.”

Like many of you, I have a Facebook account. Right now I’ve got 429 Facebook “friends,” people with whom I share information almost daily, such as an observation on something I’ve read or a comment on something they’ve said. Each day I get perhaps a hundred “status updates” from others and in turn I may post one or two tidbits myself. It’s a good way to keep in touch with people I haven’t seen in years or have just met. But I’m also “friended” with people, because of some common interest, whom I’ve never seen. In that sense, 429 is not such a large number. I know some who have well over a thousand, and counting. In principle the number of familiar strangers and FB friends we know seems to have no limit. (although Facebook imposes a 5,000-friend cap).

But according to psychologist Robin Dunbar, there is an upper limit how many people with whom we can maintain stable relations. That limit is called “Dunbar’s number.”

Dunbar’s Number

While we may have hundreds of FB friends, we have much more contact with some than others. The sociologists Nicholas Christakis and James Fowler report that the number of such “picture friends” we have on Facebook averages 6.6. They tend to be people we regularly see face to face. Outside of family they are the ones we feel most strongly tied to.

Dunbar theorizes that our brain power evolved in order to maintain these kinds of close relationships. From our grooming habits as prehistoric primates to the banter we share over lunch, these ties may have helped us to survive over countless generations. But again there’s a maximum number of people with whom we can maintain these kinds of personal relations. The number usually given is 150, although it can range from 100 to 300, depending on the size of your brain’s neocortex, the part that’s involved in the higher functions such as reasoning.

Wherever in the world Dunbar looked – from Neolithic farming villages to academic subdisciplines among professors – the number of people in such strongly tied social networks kept close to the range 100-300. These “tribes,” or what Edmund Burke might have called “little platoons,” serve both to connect people to and buffer them from the impersonal forces of society beyond. Often these are voluntary service clubs, religious organizations, or neighborhood associations that help us in times of need and, just as important, promote our own happiness by giving us the opportunity to help others.

From Little Platoons to the Great Society

Little platoons consist of people we know. The complex social order made possible by private property, free association, and the rule of law – what F.A. Hayek calls the “Great Society” (not to be confused with the government program of the 1960s with the same name) – is full of strangers. Markets enable us to tacitly rely on the actions of strangers – the impersonal forces of the market – for our daily bread. They make it possible to integrate our little platoons into the Great Society.

In the “old stone age,” before permanent settlements appeared in the Near East about 10,000 years ago, Dunbar’s number was a binding constraint on the effective size of the community. Without markets strangers meant danger not opportunity. Security meant familiarity, but familiarity limited individual growth and the division of labor and knowledge.

In the first large settlements, such as Jericho and Çatalhöyük, agriculture and trade exploded, launching the so-called Neolithic Revolution, in which socially distant groups were for the first time able to extend weak ties to one another, making it possible to form unprecedentedly large and complex communities. Opportunities for trade and free association expanded exponentially, in turn creating more weak links and more opportunities.

And just as on Facebook, where you can “unfriend” or “block” connections that you no longer like, the Great Society both encourages and enables people to leave the little platoons that stifle them and to form new ones. The genesis and development of early cities, the foundation of the Great Society, depended as much on the freedom to break old, strong ties as on the freedom to form new, weak ones. The “freedom to” presupposes the “freedom from.”

Which is why I find cities so fascinating and so important for understanding social and economic development. As I’ve written before, they are the birthplace of liberty. Cities were the first social networks. They play that role today, and despite the rise of Facebook, Twitter and the others, I believe they always will.


  • Sanford Ikeda is a Professor and the Coordinator of the Economics Program at Purchase College of the State University of New York and a Visiting Scholar and Research Associate at New York University. He is a member of the FEE Faculty Network.