Dunbar's number and community cohesion

How do you handle the Rule of 150?

[encyclo]

If you've read Malcolm Gladwell [pubcon.com] or other research into social networking, you will undoubtedly have come across the concept of Dunbar's number [en.wikipedia.org], or the "Rule of 150":

(Dunbar's number) measures the "cognitive limit to the number of individuals with whom any one person can maintain stable relationships". Dunbar theorizes that "this limit is a direct function of relative neocortex size, and that this in turn limits group size ... the limit imposed by neocortical processing capacity is simply on the number of individuals with whom a stable inter-personal relationship can be maintained."

Reference: Co-evolution of neocortex size, group size and language in humans [bbsonline.org], by R. Dunbar.

The research puts at approximately 150 the number of individuals which can form a cohesive group and in which the members can depend on a sense of familiarity and are able to track emotional facts about each other. This means that as a community grows, the dynamics of the group will change. What once held a sense of intimacy becomes more anonymous, with a greatly-increased potential of intrusion by trolls or manipulators who can take advantage of the lack of familiarity.

On my forum I have seen that the management challenge created by the larger group increased significantly once the board exceeded the initial tight-knit community. The solutions to the issues involved a greater splitting of the forum into more distinct areas of interest, so the membership was naturally split into smaller subgroups which grew together but stayed in a loose affiliation with the other subgroups on the board via community leaders.

Has anyone experienced such "growing pains" as your community became large enough that your familiarity level with members decreased, and how did you tackle the challenge?

[linear]

This is an incredibly interesting topic.

I'm nowhere near my Dunbar number on the current board I own. So I have the luxury of time to consider how to manage my pool of contacts, and possibly how to beat Dunbar.

I tend to buy into the idea that 150 is the limit, on average, of the size of a cohesive group that is concerned with survival. And that the number is lower for non-survival oriented groups. So if things get unmanageable before 150, that's actually not a breakdown in the theory the way I read it.

Anyhow, among the more interesting angles here to me is how can technology help you effectively exceed the Dunbar number. This has a lot of relevance to salespeople, elected officials, and people in certain other gigs. But we're talking about forums here.

Christopher Allen suggests [lifewithalacrity.com] that analysis of the cultural strategies that have emerged can inform the creation of software to assist. It's a great read.

So to view this idea of Dunbar triage through forum admin goggles, I suppose the size of your core community (active posters, forum diehards) is the thing to measure with the Dunbar yardstick. How can you make sure that as the group grows, everyone experiences enough attention to feel like they belong? And how do you keep track of the group?

I'm incredibly intrigued by the application of automation as suggested in Allen's post. Can the board software take on relationship management functions, reminding you to contact people, and tracking the touch points like a CRM tool does for a sales person? And further, can the software facilitate a team approach, so that an admin team can effectively share the job of staying in touch?

The futurist in me sees how a board with a relationship management plugin (or native facility I guess) could be a significant advance in overcoming a Dunbar threshold. If you've found it tough to grow your core membership, maybe Dunbar limit is in play, and possibly in the future technology can help forum admins with the problem.

(It makes me want to start work on a relationship management plugin for vB actually.)

[rogerd]

Interesting point, encyclo. I think there are some additional dynamics at work in larger forums. First, one tends to get subcommunities forming. I've seen groups nearly take over an individual forum, start posting chit-chat, etc. In essence, they create a mini-coommunity in the midst of a larger one.

Social network theory also talks about "connectors" - in the context of the dynamics within a very large forum, these would be the individuals who are active in quite a few of these mini-communities, and form some of the linkage that holds the larger group together.

[encyclo]

I would consider my admins as the "connectors", as they successfully bridge the gap between the different sub-groups which have coalesced around different sub-forums. I find that my membership tends to gravitate towards specific issue forums, spending the majority of their time within a their smaller sub-set and only more rarely interacting with the wider membership.

I was wondering whether anyone is doing any active "group-management", trying to split the membership into manageable chunks to keep the conversation and level of trust going?

[Webwork]

The research puts at approximately 150 the number of individuals which can form a cohesive group and in which the members can depend on a sense of familiarity and are able to track emotional facts about each other.

Ever visit a country doctor's office? The one doc that serves are whole community? There's more than 150 relationships at work.

How about a minister of a sizeable congregation? A busy law office? Is the expectation of group cohesion a function of how much "intimacy" is exposed - put out there - with some expectation of absorbtion and storage?

I suspect the notion of limits needs context:

• What is "expected of the relationship"? The lower the expectation the larger the number.
  
• How good is the "notekeeping"? We don't keep written notes about most people we interact with. Forum posts/profiles and medical files serve as reminders that unavailable in ordinary relationships.
  
• Do the cohesive factors of an online community, typically of common interest, provide a different way of gluing facts to people - versus how we might remember in the public at large?
  
• How much can can be presumed about the nature of any communal member by the nature of the communal glue? If you are considering joining the Elbonian Ultraconservative Evangelical Widgetthumping Parachuting Monks do you already know that you share a substantial nucleus of values or beliefs or . .?
  
• Face time is a different experience than message board time. Might be more noise, might be less noise. Might be different distractions or fewer distractions.

So many variables . . for those of us who love ponder the effects of variables . . :)

I think what makes a difference in scaling an online community might be the set of values that are plainly stated and effectively "enforced" - as a condition of membership. Things aren't quite so formal in ordinary relationships, as we don't hand one another written T.O.S., TCU, Program Policies, etc. At one end of the spectrum you might have a very exclusive membership. On the other end CraigsList might be a community with a small set of cohesive values (live and let live?) that would serve as one level of glue and therefore serve a a foundational element of a relationship.

What's all the more interesting about online community cohesion is the ability of the WWW to aggregate people from across countries and across the world. Despite considerable ethnic and cultural differences commonalities dominate in online communities. That gives me hope, that in time the WWW will provide the glue needed to move humankind along from warring across borders to . . . So, it makes looking at the issue of "group cohesion" all the more an interesting study, when you consider how the glue can be produced in such a wide ranging community. Maybe it's true: "Nobody here but us human beings"? Some version of the ultimate cohesion, i.e., humanity is what we is, and now let's get beyond the trimmings?

Ah, if it was only that simple. :)

This would be an interesting onion to peel if time allowed.

[rogerd]

Something that's true about online communities, as well as real-life relationships, is that the level of participation of the individuals varies, and the level of relationship between individuals varies.

Some forum members, for example, seem to be ever-present in the forum, posting many times per day and replying quickly to any related posts. Others may pop in sporadically.

Similarly, some forum members are inevitably closer to each other - perhaps due to shared interests, common viewpoints, etc. They may interact outside the open forums by PM, email, or in person. An in-person meeting can build the forum relationships, too - after meeting people at Pubcon face-to-face and chatting with them, I now have a much better "forum identity" for those individuals.

What's the point? I'm not sure how these varied levels of relationship fit into the 150 number, or how it is meaningful. Presumably, very close relationships require more maintenance, e.g., more interaction in the forum, perhaps frequent emails, etc., so there might be some kind of practical ceiling to how many one can juggle. (Some people are no doubt more effective jugglers than others.)

How the other forum relationships fit isn't so clear. Does the guy who shows up a couple of times a month count in my 150?

Upon reflection, I think the 150 number might be most useful in fairly regimented conditions - the military unit being one example. Others might include a college dorm, a fraternity house, a very active club, etc. In these cases, some level of interaction is inevitable due to external conditions, living arrangements, etc.