Comments on: What’s the new Dunbar number?

By: linda

linda — Sun, 22 Jul 2007 04:23:18 +0000

This concept of the Dunbar number interests me in the context of a move, 6 years ago to a very small, relatively isolated town. I found the number of people with whom i was expected to engage in conversation which included personal information skyrocketing, whether i wanted it to or not. These interactions often felt oppressively effluvial, and yet, their intimate nature made them difficult to resist/avoid. Meanwhile, i increasingly use the internet for conversation which is more interesting and substantial. I find myself feeling greater intimacy with those who share their careful thoughts, but whom i never imagine physically meeting, or sometimes, even interacting with electronically, than to those whose stories i hear when i’m trying to buy groceries, but must be cordial with. I think often about the real meaning of that word, cordial. As well as the evolving meaning of the word friend.

By: Bri

Bri — Wed, 04 Jul 2007 13:16:20 +0000

Reducing human contact and human relationships to a congealed mathematical number is, indeed, the oddest thing I have yet to read in a blog. Why actually bother with this? Are our lives so quantity-based and -nourished that we have to extend that way of thinking even to our most fundamentally human things? Hmm.

By: Fabrizio

Fabrizio — Mon, 02 Jul 2007 11:02:34 +0000

As a professor and consultant I spend most of my time in classes and groups and I have noticed that Dunbar number suffers some kind of asymmetry: on the whole I meet and share time with almost 2000 people per year. The number of people course participants meet is usually less than 2000 and perhaps more close to the Dunbar number: this brings to the fact that I receive a lot of invitations on Linkedin etc from people that consider themselves as related to me and that I can hardly remember. How could you define this situation?

By: Carol Gee

Carol Gee — Mon, 02 Jul 2007 06:21:46 +0000

Grant, I have found this post and comments very thought-provoking. I’ll add my “two bits worth.” “Social contacts,” it seems to me, are those people with whom we keep in touch because we want to, not because we should. Other words are perhaps more accurate for the latter – associate, acquaintance, contact, neighbor, friend-of-a-friend, etc. Using “friend” as a category is a risky business, because being a friend brings expectations of acceptance, reciprocity, intimacy, etc. Thus, my true friends know all, or most all, of my secrets and love me anyway.

By: MAS

MAS — Sun, 01 Jul 2007 13:16:19 +0000

I think we are capable of expanding our personal Dunbar number by our required circumstances. When I worked in finance, we had 100+ people in our section, and I knew them all, their families, etc. Add into that mix the 100+ that attend the church I go to whose homes I’ve been to and that I’ve invited here. Then, there are the social clubs, online social networking, etc. And family, extended family, etc.

And, I’m an introvert!!!

Interesting theory. I wonder who I should drop since I’m well over my limit….

By: lauren

lauren — Fri, 29 Jun 2007 19:43:53 +0000

following on from what william was saying, if i was going to calculate all my friends on all my online social networks into the dunbar system, i think they would probably only count for 1, maybe 2. not ‘cos i’m a loser and only have that many friends, but the evoloutionary mental capacity that i’m using is only that i use myspace to access my friends – i don’t need to actually *remember* things about them, like names, birthday, what their favourite colour is, what their girlfriends name is, etc, as all that information is actually given and easily accessible outside of my memory. in fact, given that blurb (which is not based on anything except waffling) i would say that with online social networks, the dunbar numbers will start to go down. we’ll start to only retain the information about where to get information about our relationships from, not the actual information.
does any of that make sense or am i way off?

By: William Newman

William Newman — Fri, 29 Jun 2007 11:40:58 +0000

Wasn’t the Dunbar number originally the extrapolated natural band/tribe/pack/whatever size for humans? As I understood it, it was not so much the people you had casual knowledge of, even useful casual knowledge of. Instead, it was the number of people you could keep enough track of (following reputation and trust and mutual obligations and whatnot). And below that number, things could Just Work (without post-monkey technology like formal hierarchy and written rules and so forth). If I’m not mistaken about that understanding, then most of the anecdotal evidence here seems to be missing the point. Monkeys have useful casual knowledge of many, many things (fruit-bearing trees, water holes, paths). But keeping track of everything you need to know about another band member seems to be expensive enough that their bands stay much smaller than the number of food sources that they can remember. Until someone shows me otherwise, my guess is that Facebook-level power tools for the brain just make it more convenient to keep track of useful people in a way that is comparable to the way a nomad keeps track of useful oases and water holes, and don’t have much to do with the way a nomad keeps track of his second cousin in the third tent to the left.

If you wanted to address what I understood to be the point of the Dunbar number, I think it would make more sense to use anecdotes from collaborations over the Internet. I run such a collaboration, a software development development project (“SBCL”). It currently has about twenty developers authorized to write to the central source code database, and runs basically without formal procedures. I have been pleased how well that has worked up to 20ish developers, but don’t think it would work past 150, with or without Facebook technology.

I do rather expect that other forms of computer power tools for the brain will tend to let us bypass or outright replace various kinds of hierarchy in large groups. I think I can even see it happening already in some kinds of large groups (with citeseer and arxiv, for example, and arguably google too). But I’m not sure the particularly vague touchy-feely services like Facebook are the same kind of thing. They’re very important in their own way, but they seem pretty separate from the harder scaling cutoffs that I thought the Dunbar number was about. An infantry platoon is a very different organizational animal than an infantry battalion, and no one has figured out how to soften the difference very much. Scientific journal communication in a field with 5000 researchers used to be a very different thing than in a field with 50 researchers, and it looks to me as though we have figured out how to soften the difference a lot. Facebook and the like have had a huge impact in their way, but I’m still uncertain how it fits in. Among other things, note that Facebook doesn’t seem to be addressing a problem which was previously addressed by hierarchy and formal rules. Maybe with a few years of hindsight it’ll be easier for me to figure it out…

By: neilperkin

neilperkin — Fri, 29 Jun 2007 09:22:37 +0000

Definition is everything in this game. I suspect that the degrees of social relationship between ‘friends’ on online networks varies wildly (as you intimate) but perhaps what they facilitate is more efficient management of all those ‘tier 2′ friends…people you know and like but who’ve not necessarily seen you drunk and making a fool of yourself…

By: LK

LK — Thu, 28 Jun 2007 15:14:47 +0000

Peter,

maybe take the 5 minute walk and ask Prof Dunbar how many contacts he has on linked in, facebook, etc?

i have been playing around with friendster, my space, linked in, and facebook … so for about 4 years now. it was a game at first, then it became a performance (ie many seem intent on showing the rest of the world that they have 573 ‘friends’) but what i’ve found so often is that people that are barely friends or colleagues — barely in the sense that there’s not much of a foundation for a relationship — send out an e-invitation after a cursory interaction. So this definition of “friend” is very different from Dunbar’s 150. There’s a qualitative aspect in his number that may well still hold true.

By: Peter

Peter — Thu, 28 Jun 2007 13:24:01 +0000

If we add to our list of friends-in-the-physical-world all those people we feel ourselves to be good friends with in the world-of-TV-and-film-fiction (eg, CJ Cregg, Detective McNulty, Tony Soprano, Jason Bourne) — ie, “people” we care about, and whose “lives” we follow with interest — then we probably easily reach a number greater than 150.

BTW — Professor Dunbar’s office is 5 minutes walk from where I write this.