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Steve Mallett

Steve Mallett
Feb. 08, 2003 04:14 PM

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I've been reading about communities lately though I didn't really mean to. I started out reading about 'emergence' and 'tipping points' over the last few months and stumbled onto something that web communities may find useful. It's called 150.

I'll start with The Tipping Point's take on 150:

Quoting Dunbar (pg 179): "The figure of 150 seems to represent the maximum number of individuals with whom we can have a genuinely social relationship, the kind of relationship that goes with knowing who they are and how they relate to us. Putting it another way, it's the number of people you would not feel embarrassed about joining uninvited for a drink if you happend to bump into them at a bar."

There then goes on to be several examples of how social groups (religious and working) are a better unit if split whenever one group grows beyond that magic number of 150 members. To grasp the idea of 150 Gladwell suggest we think about our phone numbers. They are seven digits because seven digits is all we can handle:

Quoting Miller (pg. 176): "There seems to be some limitation built into us either by learning or by the design of our nervous systems, a limit that keeps our channel capacity in this general range"

At the time of reading Tipping Point I thought this was a pretty intriguing mystery, wondering why 150 in the case of groups of people? Or as Gladwell puts it as our 'Social Capacity".

I'm still reading through Emergence: The Connected Life of Ants, Brains, Cities, and Software, but I ran into the number 150 again when reading about human's natural tendency to imagine other people's mental states:

"That power (imagining other's mental states) came in the form of brain mass: more neurons to model the behavior of other brains, which themselved contained more neurons, for the same reason. It's a classic case of positive feedback, only it seems to have run into a ceiling of 150 people, according to the latest anthropological studies. We have a natural gift for building theories of other minds, so long as there aren't too many of them."

So there it is again. 150. The magic number hardwired into us , like it or not.

Johnson writes about that, but in terms of a city's community structure:

"Those oversize communities appeared to quickly for our minds to adapt to them using the tools of natural selction and so we hit upon another solution, one engineered by the community itself, and not by its genes. We started building neighborhoods, groups within groups."

Groups within groups. We fork. We make like a banana & split. Like a cell. So where is the interest for online communities? In case you haven't guess yet let me share my personal 150 entity situation. I've found that bloggers are outpacing slashdot for innovative topics and conversation and I don't think it's the blogging mechanisms that achieve that as much as the natural selection of bloggers they connect with. The number of blogs that I read hovers around 150. Beyond that many start to contain the same voice as others and/or are equal replacements for ones in my list already and so don't add any value. I might swap some blogs out and others in as my interests change, but yep, 150 is about right.

Consider another phenomenom we've all experienced. You join a community, whether it's an email list, website or other and it gains some popularity and so the members in the community grows into an unmanagable size. When I say manageable, I mean self-managing. And so you leave or become frustated and you lament the 'good ole days' of what your community was.

Weblogs don't really suffer from this potential growth since everyone act as their own entity. The slashdots, the Kuro5hins (the Ozbourns, just kidding), do where people identify themselves somehow in one site. And are these communities self-managing, harmonious places? The answer is kinda, but not really, Slashdot stories are managed from the top down and while Kuro5hin member choose their topics, they still have trolls.

Slashdot will never get rid of their trolls nor will many sites, but what if you only ever saw 150 other slashdotter's/K5er's comments? Hard to hide in that small a crowd isn't it? That's because you're not a crowd as much as a neighborhood now. You are no longer downtown.

It would be healthy to be able to visit other communities, check them out, maybe move in if someone wants to move out. The smartest of ideas permeate throughout a large mass of people to the entire larger community. Highly moderated comments from any neighborhood would become visible to all neighborhoods.

Enough particulars, you get the idea.

This social channel capacity is something that online communities should strongly think about and play with to see what happens. I'm willing to bet that the conversations and relationships will be much richer and healthier for it.

P.S. Bloggers, go count Doc Searl's 'blogroll'. Give or take ten for link-rot and you'll find an interesting number.

Steve Mallett is the founder and managing editor of (Open Source Directory), and does a bunch of other stuff.