6 ms·

Dunbar's Number Is Quadratic (2020)

76 points by Bluestein 2y ago

cek 2y ago
Instead of viewing Dunbar's number as a law, I view it as a sometimes useful, mental model. This article is about how Dunbar's number, as a mental model, breaks down when applied to social media. It makes a strong case for that. Like all mental models, Dunbar's number is not perfect. However, readers who stop after the introduction of this article may be left thinking it's not useful at all. I find it very useful in helping leaders in early-stage organizations that are growing fast recognize why the tools & techniques they've used to get to 30-80 people are breaking down as they approach 100-150 people. It helps frame why new tools & techniques for organization and communication are required.
- ghaff 2y ago
  There are very clearly differences in how organizations have to be operated as they grow. And one byproduct of that is a person who may be a fantastic fit for an organization of size x may no longer be a good fit for an organization of size 5x or 10x.
  - Bluestein 2y ago
    > a person who may be a fantastic fit for an organization of size x may no longer be a good fit for an organization of size 5x or 10x. Interesting, in that you might even have to "backpedal" (rehire) as growth happens.-
    - ghaff 2y ago
      Of course, people leave organizations for many reasons. But a ton of people who like being in a small (however you care to define) growing organization don't have as good a place in a larger, more process-heavy one with more narrowly-defined roles and responsibilities.
- Bluestein 2y ago
  > It helps frame why new tools & techniques for organization and communication are required. Quite useful in that context, as you say, like a mental model.- PS. Interesting that the "threshold" seems to be somewhere between 80 transitioning to 100 (ballparking, of course).-
  - marcosdumay 2y ago
    Well, there is a transition at something around 20, and another transition at larger numbers too (no idea where exactly, but 500 is above the transition). I find it interesting that everybody focus on the transition at 100. (Except for educators, that are completely aware of the 20 one.)
    - Bluestein 2y ago
      20 is totally a "thing".- PS. Manywhere, average classroom size is 30ish ...
    - mistermann 2y ago
      Would be interesting to know what people in the strategy department of the US military know about this topic.
      - ghaff 2y ago
        Certainly you can look at the sizes of various units in the US Army. https://www.defense.gov/Multimedia/Experience/Military-Units/Army/ https://www.defense.gov/Multimedia/Experience/Military-Units... Of course, they have various considerations that may not apply more generally.
      - Bluestein 2y ago
        Group size as a variable must have been studied to death from the military, HR and OR angles ...
- ds_opseeker 2y ago
  Dunbar told me it grows by approximately tripling. And yes, when you cross a Dunbar bound the old tools and techniques fail in surprising ways. 15 45-50 150 450/500 1500 5000
  - ghaff 2y ago
    That feels at least directionally correct. And it even goes up from there. An organization with a few thousand people is quite different from a 20-30K one. I'm not sure about the math and exact numbers (which probably vary depending upon the situation anyway) but it's pretty clear that things are quite different at different scale points.
    - Bluestein 2y ago
      (And, should it hold, we get to cities: 100K people, 300K people, 1M people, are different cities to live in - qua size ... ... and different organizations, of course.- Leaves me wondering - among many things - what the "largest qua payroll" organization worldwide might be.- US Dept. of Defense, Chinese PLA, Indian railways. Walmart, Saudi Aramco come to mind.-
      - marcosdumay 2y ago
        Voting for a position at the government of my ~3M people city is completely different from voting for a position at the government of my ~300M people country. Logically, it makes sense that the situation keeps changing. But it still feels weird. How many different kinds of relationship are we capable of?
        Bluestein 2y ago
        > How many different kinds of relationship are we capable of? Kinds? (qualitative) ... ... I think you very much upped the ante there :) I'd posit a (cheap, easy) guess: Infinite.- PS. Of course, taking the "cheap" way out in thinking about this of assuming each one-on-one relationship (not to mention one-to-many, and many-to-one and many-to-many, like mentioned upthread) to be a unique "kind", is an easy way out: As many types of relationships as people, because no two people are alike, and so is their relationship. Heck, considering each of the individuals (themselves) involved, might subjectively experience a different relationship, there's even a "two to each pair" pairing of relationship types to participants, to be considered ... Now, when, IMHO it gets interesting is if we - a bit more rigoroulsy - attempt a "taxonomy" of relationship "types".- (And, then, again, I am sure anthropology has studied and catalogued those to death ...)
- NoMoreNicksLeft 2y ago
  > I view it as a sometimes useful, mental model. It's very nearly always useful. Many of the worst problems we have in the world around us arise because, it turns out, people just don't scale.
  - Bluestein 2y ago
    > people just don't scale. Which, if I may, applies both in the sense that groups of people "handle" differently, and differently vis-a-vis group size, and in the sense that we seem to have an innate inability as humans to deal with exponential, non-linear, "network" phenomena.-
munchler 2y ago
(2020)
aidenn0 2y ago
Dunbar's number isn't quadratic any more than the table of elements is quadratic. We can make fairly good approximations of how two elements will interact with each other just by knowing properties of the elements themselves. The analogy fails to describe people given that major past issues can color relationships, but it doesn't seem reasonable to think that the number of such major issues will grow linearly with tribe size, this those will also be sub quadratic (I am proposing that as tribe size doubles, the number of people you love/hate due to past shared experiences less than doubles).
- Bluestein 2y ago
  > I am proposing that as tribe size doubles, the number of people you love/hate due to past shared experiences less than doubles). You'd be surprised. More I know, more I like me dog, as someone said :)
ToValueFunfetti 2y ago
I don't see how this shows Dunbar's number is quadratic any more than storing 150 integers in an array from which you may need to multiply random pairs later. Computing all 22,500* pairs would be quadratic, but I don't see (or have overlooked) a justification for this in the article. Feasibly, if your whole 150 person village had a meeting, you'd want all pairs. But then you'd also want all triplets, quartets, etc which I believe is exponential. *Technically 22,350, as you don't need self pairs
- Bluestein 2y ago
  > But then you'd also want all triplets, quartets, etc which I believe is exponential. This sounds like a "so-and-so acts different towards bar in front of baz" scenario.-
  - o11c 2y ago
    The critical observation is that that information can be stored as part of the information of "so-and-so", since there are only a handful of exact "bar" and "baz" values (a few more are added via categories) per root person.
deleted 2y ago
[deleted]
fano 2y ago
One of my uncles was a politician and he was not just acquainted with some thousands of people, he talked with them and remembered everything, and even when meeting someone new outside his constituency was quite likely to know some friends or relatives. Would one call that a profesional Dunbar number!
- Bluestein 2y ago
  That is just a gift some people have.- PS. Romans, used a professional "nomenclator", that would follow you around helping you remember these things.-
tqi 2y ago
> That is, you know 150 people when you can competently predict how any two of them would interact in paired-off social circumstances without you. There is shockingly little justification for a core tenant of this piece. Which I suppose is fitting, since the origin of Dunbar's number is also shockingly thin on science...
- Bluestein 2y ago
  > the origin of Dunbar's number is also shockingly thin on science... Now that's an interesting angle. I'd be curious to know more, since Dunbar's often quoted.-

76 points by Bluestein 2y ago

cek 2y ago

Instead of viewing Dunbar's number as a law, I view it as a sometimes useful, mental model. This article is about how Dunbar's number, as a mental model, breaks down when applied to social media. It makes a strong case for that. Like all mental models, Dunbar's number is not perfect. However, readers who stop after the introduction of this article may be left thinking it's not useful at all. I find it very useful in helping leaders in early-stage organizations that are growing fast recognize why the tools & techniques they've used to get to 30-80 people are breaking down as they approach 100-150 people. It helps frame why new tools & techniques for organization and communication are required.

ghaff 2y ago
There are very clearly differences in how organizations have to be operated as they grow. And one byproduct of that is a person who may be a fantastic fit for an organization of size x may no longer be a good fit for an organization of size 5x or 10x.
- Bluestein 2y ago
  > a person who may be a fantastic fit for an organization of size x may no longer be a good fit for an organization of size 5x or 10x. Interesting, in that you might even have to "backpedal" (rehire) as growth happens.-
  - ghaff 2y ago
    Of course, people leave organizations for many reasons. But a ton of people who like being in a small (however you care to define) growing organization don't have as good a place in a larger, more process-heavy one with more narrowly-defined roles and responsibilities.
Bluestein 2y ago
> It helps frame why new tools & techniques for organization and communication are required. Quite useful in that context, as you say, like a mental model.- PS. Interesting that the "threshold" seems to be somewhere between 80 transitioning to 100 (ballparking, of course).-
- marcosdumay 2y ago
  Well, there is a transition at something around 20, and another transition at larger numbers too (no idea where exactly, but 500 is above the transition). I find it interesting that everybody focus on the transition at 100. (Except for educators, that are completely aware of the 20 one.)
  - Bluestein 2y ago
    20 is totally a "thing".- PS. Manywhere, average classroom size is 30ish ...
  - mistermann 2y ago
    Would be interesting to know what people in the strategy department of the US military know about this topic.
    - ghaff 2y ago
      Certainly you can look at the sizes of various units in the US Army. https://www.defense.gov/Multimedia/Experience/Military-Units/Army/ https://www.defense.gov/Multimedia/Experience/Military-Units... Of course, they have various considerations that may not apply more generally.
    - Bluestein 2y ago
      Group size as a variable must have been studied to death from the military, HR and OR angles ...
ds_opseeker 2y ago
Dunbar told me it grows by approximately tripling. And yes, when you cross a Dunbar bound the old tools and techniques fail in surprising ways. 15 45-50 150 450/500 1500 5000
- ghaff 2y ago
  That feels at least directionally correct. And it even goes up from there. An organization with a few thousand people is quite different from a 20-30K one. I'm not sure about the math and exact numbers (which probably vary depending upon the situation anyway) but it's pretty clear that things are quite different at different scale points.
  - Bluestein 2y ago
    (And, should it hold, we get to cities: 100K people, 300K people, 1M people, are different cities to live in - qua size ... ... and different organizations, of course.- Leaves me wondering - among many things - what the "largest qua payroll" organization worldwide might be.- US Dept. of Defense, Chinese PLA, Indian railways. Walmart, Saudi Aramco come to mind.-
    - marcosdumay 2y ago
      Voting for a position at the government of my ~3M people city is completely different from voting for a position at the government of my ~300M people country. Logically, it makes sense that the situation keeps changing. But it still feels weird. How many different kinds of relationship are we capable of?
      - Bluestein 2y ago
        > How many different kinds of relationship are we capable of? Kinds? (qualitative) ... ... I think you very much upped the ante there :) I'd posit a (cheap, easy) guess: Infinite.- PS. Of course, taking the "cheap" way out in thinking about this of assuming each one-on-one relationship (not to mention one-to-many, and many-to-one and many-to-many, like mentioned upthread) to be a unique "kind", is an easy way out: As many types of relationships as people, because no two people are alike, and so is their relationship. Heck, considering each of the individuals (themselves) involved, might subjectively experience a different relationship, there's even a "two to each pair" pairing of relationship types to participants, to be considered ... Now, when, IMHO it gets interesting is if we - a bit more rigoroulsy - attempt a "taxonomy" of relationship "types".- (And, then, again, I am sure anthropology has studied and catalogued those to death ...)
NoMoreNicksLeft 2y ago
> I view it as a sometimes useful, mental model. It's very nearly always useful. Many of the worst problems we have in the world around us arise because, it turns out, people just don't scale.
- Bluestein 2y ago
  > people just don't scale. Which, if I may, applies both in the sense that groups of people "handle" differently, and differently vis-a-vis group size, and in the sense that we seem to have an innate inability as humans to deal with exponential, non-linear, "network" phenomena.-

munchler 2y ago

(2020)

aidenn0 2y ago

Dunbar's number isn't quadratic any more than the table of elements is quadratic. We can make fairly good approximations of how two elements will interact with each other just by knowing properties of the elements themselves. The analogy fails to describe people given that major past issues can color relationships, but it doesn't seem reasonable to think that the number of such major issues will grow linearly with tribe size, this those will also be sub quadratic (I am proposing that as tribe size doubles, the number of people you love/hate due to past shared experiences less than doubles).

Bluestein 2y ago
> I am proposing that as tribe size doubles, the number of people you love/hate due to past shared experiences less than doubles). You'd be surprised. More I know, more I like me dog, as someone said :)

ToValueFunfetti 2y ago

I don't see how this shows Dunbar's number is quadratic any more than storing 150 integers in an array from which you may need to multiply random pairs later. Computing all 22,500* pairs would be quadratic, but I don't see (or have overlooked) a justification for this in the article. Feasibly, if your whole 150 person village had a meeting, you'd want all pairs. But then you'd also want all triplets, quartets, etc which I believe is exponential. *Technically 22,350, as you don't need self pairs

Bluestein 2y ago
> But then you'd also want all triplets, quartets, etc which I believe is exponential. This sounds like a "so-and-so acts different towards bar in front of baz" scenario.-
- o11c 2y ago
  The critical observation is that that information can be stored as part of the information of "so-and-so", since there are only a handful of exact "bar" and "baz" values (a few more are added via categories) per root person.

deleted 2y ago

[deleted]

fano 2y ago

One of my uncles was a politician and he was not just acquainted with some thousands of people, he talked with them and remembered everything, and even when meeting someone new outside his constituency was quite likely to know some friends or relatives. Would one call that a profesional Dunbar number!

Bluestein 2y ago
That is just a gift some people have.- PS. Romans, used a professional "nomenclator", that would follow you around helping you remember these things.-

tqi 2y ago

> That is, you know 150 people when you can competently predict how any two of them would interact in paired-off social circumstances without you. There is shockingly little justification for a core tenant of this piece. Which I suppose is fitting, since the origin of Dunbar's number is also shockingly thin on science...

Bluestein 2y ago
> the origin of Dunbar's number is also shockingly thin on science... Now that's an interesting angle. I'd be curious to know more, since Dunbar's often quoted.-