The Dunbar Number Explained

The advent of Facebook and other online social networks has made the Dunbar Number a well known concept. This article provides a nice layman’s explanation of the Dunbar number, in the words of Robin Dunbar himself. The article also points out that recent research shows that while people can have several thousand Facebook or Twitter friends, the number of people with whom they have meaningful interactions remains at around 150.

Dunbar's Number in Twitter Conversations

Dunbar’s Number in Twitter Conversations (Photo credit: Cea.)

It seems as though the concept of a ‘Technology Assisted Dunbar Number’, which I had attempted to conceptualize 5 years ago has not found empirical support – as of yet. Hope remains that technology will one day enhance the limits of human cognition and thus enable us to evolve beyond this natural barrier.

 

Key passages from the article are highlighted below:

 

 

 

Over the past two decades, he and other like-minded researchers have discovered groupings of 150 nearly everywhere they looked. Anthropologists studying the world’s remaining hunter-gatherer societies have found that clans tend to have 150 members. Throughout Western military history, the size of the company—the smallest autonomous military unit—has hovered around 150. The self-governing communes of the Hutterites, an Anabaptist sect similar to the Amish and the Mennonites, always split when they grow larger than 150. So do the offices of W.L. Gore & Associates, the materials firm famous for innovative products such as Gore-Tex and for its radically nonhierarchical management structure. When a branch exceeds 150 employees, the company breaks it in two and builds a new office.

For Dunbar, there’s a simple explanation for this: In the same way that human beings can’t breathe underwater or run the 100-meter dash in 2.5 seconds or see microwaves with the naked eye, most cannot maintain many more than 150 meaningful relationships. Cognitively, we’re just not built for it.

—–x—–

Dunbar actually describes a scale of numbers, delimiting ever-widening circles of connection. The innermost is a group of three to five, our very closest friends. Then there is a circle of 12 to 15, those whose death would be devastating to us. (This is also, Dunbar points out, the size of a jury.) Then comes 50, “the typical overnight camp size among traditional hunter-gatherers like the Australian Aboriginals or the San Bushmen of southern Africa,” Dunbar writes in his book How Many Friends Does One Person Need? Beyond 150 there are further rings: Fifteen hundred, for example, is the average tribe size in hunter-gatherer societies, the number of people who speak the same language or dialect. These numbers, which Dunbar has teased out of surveys and ethnographies, grow by a factor of roughly three. Why, he isn’t sure.

 

Another link to the article is here.

 

 

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2 thoughts on “The Dunbar Number Explained

  1. Pingback: The Dunbar Number Explained « A little bit of this, a little bit of that | Dunbar's Number | Scoop.it

  2. Pingback: Evolutionary basis of maximum connections on Facebook (150) | Tim Batchelder.com

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