One of the books I have just finished reading is Malcom Gladwell‘s The Tipping Point: How Little Things Can Make a Big Difference (Recommended). About 2/3 of the way through the book, I landed on an insight that got me thinking…

Gladwell identifies three criteria necessary for a trend (good or bad) to tip and begin to spread rapidly or uncontrollably — an epidemic. While discussing the third criteria, “The Power of Context”, Gladwell outlines what he calls “The Rule of 150.” He discusses the fact that as human beings, we can handle only so much information at once before we reach what in cognitive psychology is called our “channel capacity.” He writes, “Perhaps the most interesting natural limit, however, is what might be called our social channel capacity.” He goes on to describe the work of British anthropologist Robin Dunbar, who has observed a correllation between the size of the neocortex in the brain of mammals and the size of the groups in which they live. This can be tracked through every species of primate, where the larger the neocortex, the larger the group size. Naturally, man has the largest, and lives in the largest of groups.

If you belong to a group of five people, Dunbar points out, you have to keep track of ten separate relationships: your relationships with the four others in your circle and the six other two-way relationships between the others. That’s what it means to know everyone in the circle. You have to understand the personal dynamics of the group, juggle different personalities, keep people happy, manage the demands on your own time and attention, and so on. If you belong to a group of twenty people, however, there are now 190 two-way relationships to keep track of: 19 involving yourself and 171 involving the rest of the group. That’s a fivefold increase in the size of the group, but a twentyfold increase in the amount of information processing needed to “know” the other members of the group. Even a relatively small increase in the size of a group, in other words, creates a significant additional social and intellectial burden.

At this point one tends to think of Metcalfe’s Law, which is a positive way of expressing this exponential increase in the network. First coined by Bob Metcalf, the rule states that the value of a network is proportional to the square of the number of users of the system or nodes on the network. The law has since been applied to social networks as well. Continuing with Gladwell though,

Humans socialize in the largest groups of all primates because we are the only animals with brains large enough to handle the complexities of that social arrangement. Dunbar has actually developed an equation, which works for most primates, in which he plugs in what he calls the neocortex ratio of a particular species — the size of the neocortex relative to the size of the brain — and the equation spits out the expected maximum group size of the animal. If you plug in the neocortex ratio for Homo sapiens, you get a group estimate of 147.8 — or roughly 150. “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 happened to bump into them in a bar.”

Dunbar has combed through the anthropological literature and ound tha the number 150 pops up again and again. For example, he looks at 21 different hunter-gatherer societies for which we have solid historical evidence, from the Walbiri of Australia to the Tauade of New Guinea to the Ammassalik of Greenland to the Ona of Tierra del Fuego and found that the average number of people in their villages was 148.4. The same pattern holds true for military organization. “Over the years military planners have arrived at a rule of thumb which dictates that functional fighting units cannot be substantially larger than 200 men,” Dunbar writes. “This, I suspect, is not simply a matter of how the generals in the rear exercise congrol and coordination… Rather, it is as though the planners have discovered, by trial and error over the centuries, that it is hard to get more than this number of men sufficiently familier with each other so that they can work together as a functional unit.”

Gladwell goes on to describe the example of the Hutterites, who live in self-sufficient communities.

The Hutterites… have a strict policy that every time a colony approaches 150, they split it in two and star a new one. “Keeping things under 150 just seems to be the best and most efficient way to manage a group of people,” Bill Gross, on eof the leaders of a Hutterite colony outside Spokane told me. “When things get larger than that, people become strangers to one another.” The Hutterites, obviously, didn’t get this idea from contemporary social psychology. They’ve been following the 150 rule for centuries. But their rationale fits perfectly with Dunbar’s theories. At 150, the Hutterites believe, something happens — something indefinable but very real — that somehow changes the nature of community overnight. “In smaller groups people are a lot closer. They’re knit together, which is very important if you want to be effective and successful at community life,” Gross said. “If you get too large, you don’t have enough work in common. You don’t have enough things in common, and then you start to become strangers and that close-knit fellowship starts to get lost.”

Gross continues relating his story to Gladwell, explaining that he had been in a community that had gotten close to 150 and had seen how things changed. He described division within the group, comprising two or three groups within the larger group. (Gladwell, p.175-181)

So I’m thinking about all of this, and Gladwell has me quite convinced about a few things concerning group dynamics — which is why I’ve quoted at some length. After reading this a few days ago, I jotted a few quick thoughts and questions down in my Moleskine (yes, I’ve been converted to that cult, and can’t just call it a notebook). But I’m thinking about one of the most popular posts I’ve done, “Church Size: Tall, Venti, or Grande? in which I take what is admittedly a somewhat snarky tone at times as I criticize the “bigger is better” model of church size.

I think the phrase that encapsulates the church growth movement more than any other would be “breaking the 200 barrier” and yes, I remember thinking that way. Back in the day, there was discussion about the real barriers to church growth, and how to blast through them. Yeah. Folks, I’m not proud of those moments, and it took me a while to figure out that they aren’t the way to do things — certainly not for me. I had settled that well before I left my CLB, but when I explained and espoused a new structure for the church that took us beyond the model of the headcount on Sunday morning, the stony look from the elders extinguished the twinkly glimmering tell-me-more look in the eye of some of the other leaders. Well. I’m not there anymore, and I’m continuing to figure these things out for myself.

My latest attack may just have to be the granddaddy, the idea of “the 200 barrier” itself. What I wrote in my Moleskine was the question of whether or not we should be trying to break it at all… and I think the answer could very well be “no.” I’m going to grant that some congregations go through explosive growth periods and simply don’t even notice the 200 barrier as it glides quickly by. I’ve been in a congregation like that, and I know examples of this that I don’t want to criticize. I have some different thoughts about those settings, because they need a slightly different approach to a slightly different problem. But for those below the 200-mark who are wondering about growth… read on.

One of the things we talked about back in the day as we sought to grow the church was the very real problem that after a person has been a christian for a couple of years, they don’t have any non-christian friends anymore. The problem, of course, is that we can’t grow (except by transfers, which we didn’t want) if we don’t know any heathens unchurched unbelieving souls who we could draw in, convert to being “believers,” and get them all “churched.” I thought about that problem as I made notes in my Moleskine, too. And I realized that if these new converts keep their work and family relationships and supplant all the rest with the 120 or so people that are in the church they join, that’ll be the end of it. They’ve got the 150-ish group slots filled, and there’s no capacity for any more. We might notice congregations (our own, perhaps) that seem to have “stagnated,” having a bit of in-and-out as people come and go, with new members being quickly identified as “fresh meat.” By-and-large these congregations sit at about the same size and pretty much the same crowd that has been there for the past number of years. Perhaps we should stop wondering why.

When they start hanging around the church, we tell them they need to get into an Alpha group, where they begin making new relationshps. This is good. We put them in a home group, where they add more relationships. Also good. We make them turn and shake hands on Sundays and drag them out to special church events, get their kids into the AWANA program, all the while telling them that it’s good to get “knit in” and develop some christian friendships to help strengthen their faith. At least the goal is good. Get them involved in a ministry or committee or two, ’cause we sure could use their help, and it’s a way to express their committment to Jesus and the church (not necessarily in that order). Pretty soon, they’ve got nobody outside the church to whom to relate.

There was the real thinking that once a person becomes a Christian, most of them had about a two-year “window” in which to help bring their peer group to faith (or at least to church), and after that it would tend to dry up as everyone they knew had already heard about their conversion. We figure it all out, that a new believer may bring friends to church during their first two years, and that after that they’ll stop being evangelistic. We just never did figure out that we were doing it to them the whole time. We thought their faith was just getting cold or something, or perhaps that they were absorbing some of the passivity of the rest of Christendom. But we were doing it to them. All of our relentless “knitting them in,” while done with the best of intentions, was slowly displacing their existing relationships, using up all the available relationship-capacity that they had. And when it was all consumed, we’d sit and wonder why they stopped “witnessing” to their friends… and we’d talk again about how to break through that pesky 200 barrier, or the 400 or 800 barriers beyond that. God, forgive us.

Is there a 200 barrier? If what Robin Dunbar says is correct, and if all the supporting evidence and the literature describing it can be believed at that level, of course it’s true. But whence came the assumption that the barrier should be pushed past? Certainly, we want the church to grow, but by that, do we mean we want our church to grow? Do we really need that? Is the “the greater good” something beyond that kind of thinking.

I’m continuing to espouse a structure of church that centers around (read: is) small groups of people who relate together as church and not as some component part of what together is “actually” a church. But now I’ve got a new reason for this conviction… the rule of 150. If the church (in the comprehensive sense) is to grow, perhaps we can take a missional stance with people that does not displace most of the existing relationships in their individual groups of 150. I have begun to “suspect” that this will better allow the gospel to spread from group to group as they intersect, rather than continue with relying on a kind of transplant methodology that hinges around — is shaped and limited by — our individual maximum capacity for relationships… a methodology we’ve already tried and found wanting.