via MIT Technology Review

Back in the early 1990s, British anthropologist Robin Dunbar began studying the social groups of various kinds of primates… Primates tend to maintain social contact with a limited number of individuals within their group.

Dunbar noticed that primates with bigger brains tended to have more friends. He reasoned that the number of individuals a primate could track was limited by brain volume.

Then he plotted brain size versus number of contacts and

… extrapolated to see how many friends a human ought to be able to handle. The number turned out to be about 150. This number appears to have been constant throughout human history—from the size of neolithic villages to military units to 20th century contact books.

Dunbar’s Number = 150

Dunbar's Number

But now we have Twitter! And Facebook! Do these modern social networks allow us to break through the biological barrier and physical limitations dictated by Dunbar’s Number?


Not according to this recent research paper Validation of Dunbar’s Number In Twitter Conversations:

…even though modern social networks help us to log all the people with whom we meet and interact, they are unable to overcome the biological and physical constraints that limit stable social relations

The bottom line is this: social networking allows us to vastly increase the number of individual we can connect with. But it does nothing to change our capability to socialise. However hard we try, we cannot maintain close links with more than about 150 buddies.

And if Dunbar is correct, that’s the way it’ll stay until somebody finds a way to increase human brain size.

Wouldn’t you rather read about this than Gaddafi, Quaddafi, Ghaddafi? Or AWOL Democratic lawmakers and plundered state employee pension funds?

It is a good article, and a nice change of pace. It is from the New York Times so for those interested in Safe For Work and not wanting any of that proverbial “mixed content” it is smooth sailing.

The trouble with integers is that we have examined only the very small ones. Maybe all the exciting stuff happens at really big numbers, ones we can’t even begin to think about in any very definite way. Our brains have evolved to get us out of the rain, find where the berries are, and keep us from getting killed. Our brains did not evolve to help us grasp really large numbers or to look at things in a hundred thousand dimensions.
by Ronald Graham via quadportnick
Humans have walked the Earth for 190,000 years, a mere blip in Earth’s 4.5-billion-year history. A lot has happened in that time. Earth formed and oxygen levels rose in the foundational years of the Precambrian. The productive Paleozoic era gave rise to hard-shelled organisms, vertebrates, amphibians, and reptiles. Dinosaurs ruled the Earth in the mighty Mesozoic. And 64 million years after dinosaurs went extinct, modern humans emerged in the Cenozoic era….

National Geographic: Prehistoric Critters, Geology, Facts, Maps, More

Visit the site! Cool interactive time line, despite using Flash!