Magazine article The Exceptional Parent

Dunbar's Number

Magazine article The Exceptional Parent

Dunbar's Number

Article excerpt

This editorial will require a quick neuroanatomy lesson. For some of you it will simply be a review and for others it will be new ground. Neuroanatomy is a subject I know well; I took it twice. But no sweat, I will lay it out for you with the beauty of simplicity.

The "neocortex" is a part of the brain of mammals. Still with me? It is the top layer of the two hemispheres. See the beauty of neuroanatomy when it's made simple? In small mammals it is smooth, but in higher animals (like us) it has grooves and wrinkles. These folds increase the surface area of the neocortex without taking up more volume.

That comes in handy when you need to adjust the band on a new ballcap. That's it for the neuroanatomy ... told you it was gonna be a breeze.

And while I never mentioned anything about having to also know some neurophysiology (what it does) this will only take a moment; and I promise to deliver it in the same poetic simplicity. The neocortex is involved in higher functions, like deciding on take out or having leftovers. It handles stuff like sensory perception, the generation of motor commands, spatial reasoning, conscious thought, and in humans, language. Okay, so much for the editorial's background tutorial.

Based on shared interests, similar human traits and values, I like to think that everyone who reads Exceptional Parent magazine could potentially be my friend. In fact, over the years I have spoken to, corresponded with, and met thousands of readers and remain convinced that this premise is almost guaranteed.

Except for one thing; my "neocortex." It seems it's too small for me to have that many friends. There's a number, a limit that provides a ceiling to how many I could actually be friends with. Dunbar's number handles that.

Robin Dunbar, a British professor of evolutionary anthropology, put forth the idea that there is a limit to the number of people with whom one can maintain stable social relationships. Using studies by field anthropologists working with primates (guess they counted the number of pals the apes monkeyed around with, pun intended) Dunbar then correlated those group sizes to the brain sizes of the primates to produce a mathematical formula. Dunbar came up with 150 as the maximum number of friends we can handle (under certain circumstances we sometimes have to recalculate the number to a single digit).

Of course he got a paper out of this, "Co-Evolution Of Neocortex Size, Group Size And Language In Humans. …

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