Robin Dunbar did an interview to coincide with his new book, and there are surprising depths to Dunbar's Number that isn't normally picked up by commentators.

Audio source: https://play.acast.com/s/intelligencesquared/thescienceoffriendship-withrobindunbarandhelenczerski

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swyx: [00:00:00] I think people who work in community and social networks think a lot about Dunbar's Number, and i was pretty surprised to hear Robin Dunbar actually talk about it recently so here's a clip from his recent interview:

Helen Czerski: [00:00:12] Let's get onto the numbers a little bit. There are these numbers that seem to be surprisingly robust. Tell us a little bit about the hierarchical structure on what those numbers are.

Robin Dunbar: [00:00:21] If you look at how often people talk with their friends and extended family, what you find is. That you can string everybody out from the person who devote most time to the person who devote less time to, but actually it's not a sort of simple line of declining contact.

It's rather bumpy. And those bumps occur in various specific. Places which cause your social network, the sort of collection of friends and extended family, you have to look like a set of ripples on a pond. If you like, where a stone has been thrown. If you think of yourself as the stone, right in the center, you're surrounded by these ripples, which go further and further out.

And in fact the analogy is quite good because the inner most ripples are usually a bit higher than the outer, most ripples of getting towards flat as the energy dissipates. So the inner most layer, or the ones you devote most time to, in fact, you devote 40% of your total social effort to that inner core of just five people.

And then beyond that, you titrate your time, according to the value of the relationships in many ways. And you end up with these quite distinct layers and the layers count cumulatively you see. So each layer includes the layer inside it, but there technically one and a half, right in the center, five, 15, 50, 150.

And then they extend beyond that 150 is your sort of natural social networks, but they extend beyond to 500, 1500, 5,000. That's the largest circle we know anything about. And it really seems to differentiate between. Completely anonymous people, people you've seen before somewhere, or you recognize the photo, but it's probably as much as we can actually cope with, but those layers, we pick them up.

Not only in face-to-face interactions, we pick them up in telephone databases, if you look at how often people phone each other. You can see it in Facebook, if you look at the frequency with which people post to named individuals. We've even picked it up on Twitter. Pretty much anything you look at. If you look at the structure of organizations, the structure of natural groupings of humans, you see the same layers.

They're extremely robust.

swyx: [00:02:32] There's an implication here of how Dunbar communities form an us versus them approach. And Robin Dunbar actually proposes that there are some ways in which we find connection across very, very large groups.

Helen Czerski: [00:02:43] You can't just have a group that gets bigger and bigger and bigger. Eventually it'll split into two groups. And even you say, around the dinner table, if you have eight people, it tends to split into two groups.

There's a lot of what feels like tribalism to me in society is a lot of us. And then you're all a lot or you're there a lot and a lot of people and I have to confess I'm one of them would just, wouldn't it be nice if everyone just stopped being in a tribe and just all got on, is that is nine nice that LIDAR of everyone.

Not belonging to a very strong, bonded social group and just, accepting people. Is that a pipe dream? Are we programmed that there has to be an us under them at some points, because if you've got people in your social group by definition, there are people that are outside it.

Robin Dunbar: [00:03:21] Partly obviously it's all the screaming stuff, but we also do it at a cognitive level, a psychological level, whereby we look for people who are rather similar to us, so-called homofeely effect, which is why we get these echo chamber effects. We tend to like people and spend, want to spend those time with people who are similar to us and a whole tranche of in particular cultural dimensions, which we call the seven pillars of friendship.

And these are things like shared interests and shared moral views and shared sense of humor, shared musical tastes and so on and so forth. And it turns out that we're very good at building kind of mega communities out of one single dimension. So normally. With your nearest and dearest you'd perhaps share.

Six or seven of these seven pillars wisdom. So if you'd like to think of them as a supermarket barcode of your kind of interests in hyphen and so on, on your forehead or accepts that you speak them obviously, but sort of when you get down to the nether, reason regions of your social network, you might only share one or two, but being able to take one of those.

As the basis for creating friendships with what amount of friendships with strangers seems to be a skill that we've managed to develop quite effectively. So this is the thing

Helen Czerski: [00:04:41] where, someone supports the same football team, or they play the same sport or it's that sort of thing.

That, that is enough that we're already automatically on the same side. We've got shortcut. Yep.

Robin Dunbar: [00:04:50] Absolutely. And that's exactly what it is. It's a shortcut through get having to get to know them better paradoxically though. The one thing that seems to be particularly good at creating a sense of bondedness with a complete stranger is your musical taste.

So if they liked the same music as you boy, you're onto something good here.

Dunbar's Number: Pt 1 - Hierarchy

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