
Dunbar's Number - benbreen
https://en.wikipedia.org/wiki/Dunbar%27s_number
======
jameskilton
I'm starting to wonder if Dunbar's Number is why so little empathy exists on
platforms like Facebook and Twitter. Social media has been trying to scale
this number, but our brains don't work like that. I wonder if, when we've
surpassed our own personal limit on personal connections, our brain
compensates for the overload by focusing on only what we see, e.g. text,
images and video, thus making us incapable of interacting as if we're talking
to another human being.

Some things in life weren't meant to scale, and there are a lot of companies
trying to do the literally impossible; causing far more damage to their users
than they'd ever do good.

~~~
anvandare
If I were not of the opinion that social media is more damaging than
beneficial to humanity, I'd like to see a social network that limits the
number of people you can interact with to ~100. Want to add a new person? Then
get rid of an old one.

Similarly, hard-coded limits to contact lists, e-mail address books, etc. It'd
never work, but I'm curious what the effects would be.

~~~
awalton
> I'd like to see a social network that limits the number of people you can
> interact with to ~100. Want to add a new person? Then get rid of an old one.

You can do this on your own if you so care - I use Twitter in pretty close to
this way (I follow 158 accounts as of today, and ~10 of them are service
status accounts). Anything over that I might also be interested goes on a List
and I check them whenever I'm bored (and I also cap lists at ~150 or so
accounts, but none of them are even close to that).

I'm of the opinion that software shouldn't build limitations, it should only
be a tool for how users want to use it. (It could be a better tool by instead
telling users "Hey, you're following a lot of users, things are probably
pretty noisy for you huh? Maybe you want to use a list for {these similar
accounts} or something?")

~~~
marblar
Do you think Twitter, a social network famous for its character limit,
shouldn’t build limitations in how its used?

------
s_dev
Dunbar's Number seems to be the crux of Paul Graham's "You Weren't Meant to
Have a Boss" without citing Dunbar's number. Just an observation.

>What's so unnatural about working for a big company? The root of the problem
is that humans weren't meant to work in such large groups.

>Another thing you notice when you see animals in the wild is that each
species thrives in groups of a certain size. A herd of impalas might have 100
adults; baboons maybe 20; lions rarely 10. Humans also seem designed to work
in groups, and what I've read about hunter-gatherers accords with research on
organizations and my own experience to suggest roughly what the ideal size is:
groups of 8 work well; by 20 they're getting hard to manage; and a group of 50
is really unwieldy. [1]

>Whatever the upper limit is, we are clearly not meant to work in groups of
several hundred. And yet—for reasons having more to do with technology than
human nature—a great many people work for companies with hundreds or thousands
of employees.

~~~
dahfizz
Isn't this solved by the organization structure of large companies? In a
company of hundreds or thousands, nobody needs to know everyone else. You
really only need to / should know your team of 5-20 and a small handfull of
management above/below you.

That way, it doesn't matter if you work for a company of 20 or 2000 because
you only interact with a manageable subset of all employees.

~~~
munin
This is fine, except then your teams interactions with another team might as
well be interactions with a competing company. This produces some behavior
that can be difficult for outsiders (customers, the CEO, etc) to understand.

So it works well as long as your teams don't interact. And if they don't
interact, why do you have a 2000 person company?

------
cko
When I started at my company it was a warehouse of under 200 people. As the
years went by, and we added more and more staff, things seemed more chaotic.
The common consensus amongst the people who worked there for many years
(before my time) was that the boss was more personal and warm. Now she sits in
a closed office in such a way that discourages anyone from approaching her.
The organization seemed to get more chaotic and unwieldy. Because we didn’t
really organize in teams it was kind of a free for all.

~~~
psyc
I started at a company just before the dot com boom. 50 people. It was like a
family. Everyone was friendly and happy, everyone knew who was responsible for
what, and what they were like. At the height of the boom it grew to 700, and I
can only describe the psychological environment as insanity. I bumped into new
strangers in the halls every day. Nobody knew what the company's mission was
anymore. Everything was failing, and blame was rampant. The managers hid.
Training became next to impossible and most people didn't really understand
how to do their job. It was nightmarish.

------
scandox
> Dunbar explained it informally as "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"

My number is about 8 by that metric.

~~~
WhompingWindows
Yeah, bizarre that this number is defined by level of embarassment. Some
individuals experience huge amounts of embarassment for little reason, does
that mean they know less people? Ehh. I think it's just a metaphor in the end,
way to tie Dunbar's number to reality.

------
chrisweekly
Bit of a tangent, but I have a fuzzy recollection from my adolescence of
someone (my great uncle?) saying, "As you get older, you'll find you have
fewer -- and better -- friends." At the time I had my doubts about this being
a good thing, but now that I'm in my 40's it's proven true. My network
continues to expand, and I'm grateful to be connected to hundreds of people,
but my inner circle of true friends is smaller, better and more precious to me
than it's ever been.

I think the optimal quality:quantity balance is very different across one's
friendly acquaintances, professional network, and inner circle.

~~~
WhompingWindows
There's also some organizational psychologists suggesting that knowing
childhood friends into adulthood helps to ground individuals towards humility
and away from arrogance/cockiness.

------
ddkto
Robin Dunbar’s papers are very clear and accessible. If you find the concept
of Dunbar’s number interesting, I recommend you have a look at his other
papers - lots of interesting concepts!!

[https://www.psy.ox.ac.uk/research/social-and-evolutionary-
ne...](https://www.psy.ox.ac.uk/research/social-and-evolutionary-neuroscience-
research-group-senrg/)

------
forkandwait
Hutterite communities usually split at about 100 people as they grow, with a
max at 150 or so.

[https://en.m.wikipedia.org/wiki/Hutterite](https://en.m.wikipedia.org/wiki/Hutterite)

------
jdonaldson
I always thought of Dunbar's number as being closely related to our limits on
vocabulary.

Even though 150 is pretty small, you typically "know" somebody based on how
they relate to the others you know about, every permutation of who knows who,
who likes who, who is similar to who and so forth. That number could be
expressed as a power: 150^2 = ~22K. Most people have a vocabulary size of
around 10k-30K words. It's probably a coincidence, but it's a number range
that pops up a lot for medium/long term memory.

------
busterarm
[http://www.cracked.com/article_14990_what-
monkeysphere.html](http://www.cracked.com/article_14990_what-
monkeysphere.html)

------
Symmetry
In democracies there's a tension between wanting to have have elected
representatives represent smaller numbers of people so as to be more
responsive on one hand, and wanting them to represent more people so that you
can keep the number of legislatures not too far over Dunbar's number.

~~~
dragonwriter
While there are complexity issues with large legislatures, I think that it's
actually a good thing to keep the size of the legislature well _above_
Dunbar's Number. You may want complete stable working relationships in an
executive council or cabinet, but you really want (I would argue) a
significant share of relationships in a legislative body (even within a
governing majority) to be characterized by arm's-length distrust.

~~~
pouetpouet
about cabinet size:
[https://arxiv.org/abs/0804.2202](https://arxiv.org/abs/0804.2202)

------
lkrubner
At the extreme opposite of this, I started writing down all the people I knew
something about, and I realized I knew something about at least 12,000 people,
and probably many more than that:

[http://www.smashcompany.com/philosophy/i-know-more-
than-1200...](http://www.smashcompany.com/philosophy/i-know-more-
than-12000-people-so-do-you)

And you also know some facts about at least 12,000 people, and probably many
more.

Just think of your favorite music bands. You can probably list 100 bands
easily. And if they average 3 people per band, that's 300 people that you know
something of.

Knowing the upper limit on how many people we know is crucial for
understanding the complexity of human society.

~~~
Retric
This is not about people, but knowing about the connections between people. I
have no idea if say Bill Gates likes or dislikes David Letterman.

If I am going to go and say kill a Water Buffalo or tile a bathroom, then I
want some people with the skills who can _also_ work together well. That's a
lot more than knowing their name and hobbies.

~~~
lkrubner
It's good to know the Dunbar number, but if you want to understand why human
societies are so complex, you have to also know the limit. You can think of it
as almost the opposite of the Dunbar number. What is the outer limit of how
many people we can know something about?

Ultra weak ties have importance in practical ways. If I were hiring a high
level software architect, I would expect them to have opinions about some of
the big names in the history of software, maybe John McCarthy or Allan Kay or
Guido von Russom or Rich Hickley. Neither of us would necessarily have any
personal connections to those people, but they operate like the stars in the
sky, the give us points by which we can navigate the whole entirety of the
human social universe.

~~~
Retric
There is great diversity in how people think.

I have tried very hard to internalize _appeal to authority_ as meaningless so
I have mostly divorced ideas from those who had them. As such, I have never
looked into big names in any field because I feel it's not just worthless but
actually harmful.

I know many reasonably competent people who take the opposite approach and
still get stuff done.

~~~
lkrubner
At no point did I invoke "appeal to authority." Rather, we navigate a social
space via shared points. If we are discussing literature in the English
language, it is useful to know who Shakespeare, Jane Austen and Ernest
Hemmingway are. Or if we are talking about Bollywood, it is useful to know who
Aishwarya Rai or Akshay Kumar are. Or we discuss basketball, it is useful to
know who Lebron James is. None of that involves an appeal to authority.

~~~
Retric
Every one of those examples come from Culture not research.

If you want to talk about people that's different from getting things done.
Lebron James is for example irrelevant when talking about Collage basketball
so he does not impact the sport directly.

------
Aaargh20318
I wonder if this number varies per person. 150 seems a lot to me personally.
For me it's probably closer to 5 than to 150.

~~~
majewsky
I think you're misunderstanding the definition.

> Dunbar's number is a suggested cognitive limit to the number of people with
> whom one can maintain stable social relationships—relationships in which an
> individual knows who each person is and how each person relates to every
> other person.

When you're hearing "stable social relationship", you might think of the
relationship to your parents, brothers, sisters, children or partner. However,
the definition of "stable social relationship" also applies to your doctor,
your boss, your coworkers, the lady next door who waters your flowers when
you're on vacation, etc. Putting that number around 100-150 average sounds
reasonable to me.

~~~
strictnein
Doesn't Dunbar's explanation preclude a lot of those people?

> Dunbar explained it informally as "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"

~~~
majewsky
Interesting. With this definition, I can see why many people would set it at 5
or even 0. :)

~~~
bpicolo
It's a limit rather than a factor of preference is I think the takeaway

------
Anon84
Dunbar's Number is actually still visible on Social Media. Here's a work of
mine from a few years back about it:
[http://journals.plos.org/plosone/article?id=10.1371/journal....](http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0022656)

------
mathattack
The intuition makes a lot of sense. The corporate structure and processes when
everyone knows everyone (up to ~150) are very different than when they don’t.
I’ve found that 150 isn’t a hard number. Companies with more remote workers
tend to hit it sooner, and the ones that thrive adopt formalism earlier.

------
jchallis
A comforting thought for many apocalyptic folks - in a postapocalyptic world,
we will be operating at a scale much more in line with Dunbar's number and
much better fitting our natural equipment.

~~~
JoeAltmaier
Hm. Our 'natural equipment' has evolved for civilization at an amazing rate in
the last 50,000 years. We're not really suited to a wild existence over most
of the globe any more. Heck, take away glasses and insulin and a huge number
of us die the first week.

~~~
fouc
Most people can get by without glasses in a world where they don't need to
read or drive. Also most people wouldn't be diabetic on a wild forager diet.

Most of humanity are still living in rough conditions also.

Only a small percentage of humanity would die off and the rest would re-
acclimate. There hasn't been all that much 'evolution' aside from some
selection for intelligence.

~~~
JoeAltmaier
Most of humanity is housed and fed. We shouldn't get our image of the world
from movies. Nearly every country has made great strides in the human
condition in the last century.

Anyway, no way the current ecosystem supports the current human population.
Its only thru intense civilized effort that we've built these hives of
humanity. The die-off would be immense.

And because of competition, those who are fit will dominate. So the glasses-
wearing insulin-needing people will be first to go.

------
nwah1
It should be noted that this is derived using extrapolations from chimps based
on brain size.

Nothing more.

~~~
Anon84
True... but it has also been verified empirically in various contexts. For
example:
[http://journals.plos.org/plosone/article?id=10.1371/journal....](http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0022656)

------
lordnacho
Sounds more or less like that amount of people you'd invite to a wedding.

------
dalbasal
under "criticism"

 _Philip Lieberman argues that since band societies of approximately 30–50
people are bounded by nutritional limitations to what group sizes can be fed
without at least rudimentary agriculture, big human brains consuming more
nutrients than ape brains, group sizes of approximately 150 cannot have been
selected for in paleolithic humans._

Evolutionary psychology/nutrition is based on a lot of guesswork. We don't
really know how people lived, or what timescales are important.

A lot of the early conjectures about historical developments are based on
philosophical thought expirements of 19th century intellectuals. Others based
on hunter-gatherers in modern times. These theories tend to be "economic"
(like Malthus) and resource focused. _" Agriculture created surplusses, which
enables specialization..etc. underpants.. Greek temples"

In eastern Turkey there are fascinating sites from the paleo/neo-lithic
transition period. Interestingly, the massive & seemingly ritual/civic site
(gobleki tepeh) predates the agricultural sites. Ie, it seems a large complex
pre-agricultural society existed, with many people cooperating in ways we
thought were first developed by advanced agriculturalists.

One could reasonably (though not conclusively) interpret this as large-scale
culture giving rise to agriculture, not the other way around.

Humans are behaviourally diverse. I imagine one would find groups of various
size at all prehistorical times. For analogy, wolves are somewhat behavioural
diverse. Many are solitary. Some hunt mostly rodents, and live in small packs.
Some hunt mostly large game, and live in large packs. Some scavange more.
There is a negotiation between wolves' inherent behavioural range and the
"economics" of their lifestyle that dictates group size. Humans have a much
wider range.

We don't really know much about early humans, even what they ate. We can guess
though, that this varied more than it does in wolves.. at least I think so.

I recently heard a lecture on archaic sapiens in the Levant. One theorist
argues they ate mostly elephants which (I imagine) required and supported
large group size. We don't really know.

In any case... the reason I bring all this up is that group size, and our
ability to cooperate effectively in different group sizes is just _interesting
_. It remains (imo) central to key mystery of human origins, possibly
explaining the sapiens ascention.

Yuval Noah Harari basically narrates all human history as an increasingly
developing ability to cooperate in ever larger groups. This is the underlying
difference between language, writing, myth, religion.. The communism-
capitalism cliche is basically a debate about mechanisms of cooperation in
large groups. What we are doing now (on hn) is coordinating across a large
group, so we can _think* together.

I think Dunbar's number (or another similar one) gives us the maximum group
size for _spontaneous_ coordination, without formalization. This is good to
know.

More research please :)

