Dunbar's Number

Anthropologist Robin Dunbar postulated that humans, on average, are capable of maintaining only about 150 relationships. That's about the upper limit of people your brain can really connect with. These are the people who if you happen to meet by chance, you would not feel uncomfortable having a drink with them. There's a lot of research that seems to back that up.


You can look at everything from hunter gatherer societies, to Medieval villages, to Facebook friends. In the real world, the number pretty much holds true.

So what can we do with this information. Well first off, if you think your 1000 Facebook friends are real, they aren't. You can't possibly invest enough social energy into all those relationships. It's pretty humbling, at least for me, to realize there is an upper limit on the number of people we can really connect to. Sure, that 150 is an estimate. No doubt there are those who can invest more into social relationships and connect with more. On the other side of the equation are those who hardly connect with anyone.

It did get me thinking. Soldiers don't connect and fight for the whole army. They are fighting for that tight group of men around them. How about other large organizations? Think about it, do you join a large organization because of the thousands of people in it, or do you join because your three best friends are in it? That's how I ended up in the Boy Scouts.

It used to be that just about all those 150 or so people were in fairly close physical contact with you. Maybe a few relationships were maintained through letter writing. Now we have social media so we can put social energy into relationships with people far away.

That's great, especially if you expect to be physically close to those people again. The problem arises when your Dunbar Number is almost totally filled up with people you only connect with electronically. What you need are people who will be there for you in a pinch. That Facebook friend is nice, but if you need an emergency baby sitter it helps to really know the folks in your neighborhood.

You can do a lot with a 150 people. If you have connections with a lot of people locally, you are in better shape in a SHTF situation. That's a big enough group to have a variety of skills and goods to exchange. A gift economy will work just fine for that number. If someone is in your tribe, you can contribute to their welfare knowing the tribe as a whole benefits. That's payment enough. Social connection is worth real things.

Strangers are the ones you have to have a more formalized exchange with. At the bare minimum you can do a one to one barter deal. The invention of money allowed people with no social connections to exchange things of value. Interesting invention that allowed complex economies larger than our Dunbar number. However, if the currency loses its value, you'd better have some real social connections.

-Sixbears