Social networking beyond the Dunbar number of 150

September 20, 2007

In a short time social networking tool Facebook has gathered 50% of the population between the age of 23-35 in Sweden as members. Impressive numbers, but Facebook is not the first social network site on the web and most likely not the last either. There’s hard competition between the MySpaces, Lunarstorms and LinkedIns of the web world. It seems like the popularity of social networking sites is like that of popular nightclubs. The cool places to be one year is not so cool anymore the year after. Friendster and Orkout knows about this all too well and Sweden-based Lunarstorm seems to be learning it as well.

Current hot-place-to-be Facebook also knows this and therefore calls themselves a “social networking utility“. A utility, a tool, is something you use to build things, so a social networking tool ought to be something you use to build social networks with. They have a somewhat open API, making them a kind of platform. Their strategy is to become the social networking operative system of the web. The Microsoft Windows of social networks. We’ll see if they make it.

So, is the market for social networking sites saturated? I don’t think so and the explanation for this also explains how GlocalReach will fit in to the social networking landscape.

Let me begin by drawing some circles:

Dunbar numbers

These circles represents circles of intimacy and is taken from the book Evolutionary Psychology by Robin Dunbar, Lousie Barrett and John Lycett. It’s called the social whirl. The number in each circle is the approximate number of people within that part of your social network. In the middle is you, followed by your family and very close friends (about 5 people). The next circle is your sympathy group, 12-15 people with whom you have a closer relationship.

The number 150 is often mentioned as the Dunbar number:

Dunbar’s number, which is 150, represents a theoretical maximum number of individuals with whom a set of people can maintain a social relationship, the kind of relationship that goes with knowing who each person is and how each person relates socially to every other person

In other words: it’s your circle of friends.

It’s people who knows you as an individual. You have a personal and explicit relationship to these people. Basically, it’s the people you have beer with.

Evolutionary psychology studies has shown that people are incapable of maintaining a close relationship with more than a 150 individuals at the time (although the number varies between persons, 150 is the average). If you meet new friends, some of your older friends that you don’t see very much anymore falls out of your 150 circle. (Don’t feel so bad about it, we’re only humans after all. You’re lucky not to be a chimpanzee. They have a Dunbar number of ~50.)

The existing social networking sites and somewhat older social tools such as the address book in your mobile phone does a pretty good job of managing these 150 people. With GlocalReach, we’re trying to build the tools necessary for the outer circles, beyond the Dunbar number.

At these circles, people know you more by a role you have or a category of people you belong to. They might know you as a politician, a programmer, a neighbor, a nurse or a blogger. If you have a slashed career people will know you by many labels and roles. GlocalReach will help you manage these roles and how people reach you from the outskirts of the social whirl. That’s our place in the social network universe.

I would have hoped to have our beta ready by now, but we have been rethinking some of the concepts, putting a stronger emphasis on the business card (or reachcard) as the center of the service, as your primary reach management tool. So, the beta will take a little bit longer. Sorry about that.

Meanwhile, give someone that has been falling out of your Dunbar circle a call. Reunite with old friends. Bring up some good old memories.

Real friendship, after all, doesn’t have a number.

Updated: here is a longer and much more insightful post on Dunbar numbers and social networks.

Updated 2: Thomas Vander Wal at the blog Personal Infocloud has an interesting post on Selective Sociality and Social Villages that touches the same subject.

I also updated the picture used in the post.

Erik Starck
Managing Director, Co-founder
GlocalReach

6 Responses to “Social networking beyond the Dunbar number of 150”


  1. […] I wrote a text on Dunbar numbers and social networks over at the GlocalReach blog. […]


  2. […] skrev jag en liten text på GlocalReachs blog om sociala nätverk och Dunbar-siffran 150. Min teori är att det finns plats för flera olika […]


  3. […] säkert anledning att återkomma till GlocalReach inom kort på denna blogg men ville peka till ett inlägg som Erik skrev på GlocalReach-bloggen där han pratar om […]


  4. […] own company, GlocalReach, will solve a slightly different problem in another circle of intimacy but the address book in the phone is definitely one of the untapped goldmines of social networking. […]


  5. […] Social networking beyond the Dunbar number of 150 « ReachCards – the blog Dunbar’s number is a theoretical cognitive limit to the number of people with whom one can maintain stable social relationships. These are relationships in which an individual knows who each person is, and how each person relates to every other person. Proponents assert that numbers larger than this generally require more restricted rules, laws, and enforced norms to maintain a stable, cohesive group. No precise value has been proposed for Dunbar’s number, but a commonly cited approximation is 150. […]