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] Something I also learned about the Dunbar number is that it's very tied to age. We don't always stay at. 150, we start with about one or two wishes, our parents then we get to about five with our closest friends. Then in our twenties and thirties, we overshoot and go to about 200, 250 people. By our thirties that drops to 150. And then into our sixties and seventies, it continues to decline. And there's an age related dynamic to this which i didn't really appreciate

Helen Czerski: [00:00:30] Albert wants to know about the correlation between age and the ability to form friendships. And what's, why is there a connection between age and new friendships? And he also, I assume it's, he says at the end, I've personally found there to be a negative correlation which is. Diplomatic, I guess.

Robin Dunbar: [00:00:47] Yeah. So I used to getting very close to home to what happens to be age. Yes. So actually you can think of this really as a sort of arc that you start out at birth and it's an arc, which involves the circles. So we do seem to acquire the circles of friendship as complete circles, as it were over time and correspondingly, we lose them as we age, but th the arc looks something like this.

You start out. With as in a core of about one and a half there, obviously your parents, as it were by about five, you can reach the five threshold. And then as you age, you can accrete the various layers as your social and cognitive skills developing, and you can handle them.

They want, it seems to happen is in the late teenager, early twenties. You overshoot as it were, but they commonly get up to about in terms of face-to-face and meaningful friendships, roundabout 200, 250 people. And then it's by the thirties that will cut down and drop to about 150, which is the sort of, obviously there's various individuals vary around these numbers, but these are the average numbers from about the thirties through to.

Perhaps the late sixties, it's very stable at about 150. And then you go into. This sort of period of terminal, I'm afraid decline from perhaps 65 70 onwards, where you gradually lose the layers and end up if you live long enough, backup one and a half. Again. Now that's a consequence of that end of losing people in your sort of layers dying, or maybe even moving away or becoming unavailable for other reasons.

And. If you were in your 20 somethings or teenager, if somebody moved away like that, you would simply replace them with somebody else. You would go to the usual venues that, that, where you meet people and you would find somebody else to add in and replace the missing person. I think what happens when you get to all this, the general sense in the literature is w w.

We've only done a small amount on on, on this aspect of it. Once you get to the older age, you just no longer have the motivation and the energy to get up and go to places where you're going to meet new people to fill out that. And also you're not sure what people. Talk about anymore, if they're younger than you or complete strangers who built up this cozy little world, which has been very stable in the latter decades of your life and you're embedded so much within that you're probably less well engaged with the wider community.

Than you would be when you're younger. So you don't, you're not sure about going to, clubs or whatever, where you would stick out like a sore thumb anyway. And B you don't know how to ask or invite a conversation. What kind of conversation do you have? What do you want to talk about?

Helen Czerski: [00:03:36] So it's not that you can't form friendships. It's more that, there are a few opportunities and you're possibly a bit fussier about, that's anecdotal entirely, but I think people spot what they want in a friend. Yeah.

Robin Dunbar: [00:03:48] Yeah. I think this is what happens in this. So the overshoot in, in the late teens, early twenties is that w we look at it as a younger people being careful shoppers, they're checking around all the supermarkets to see what's available out there in terms of the possibilities for finding good friends and romantic partners and all that kind of thing.

And once they've had a look at what the market looks like, then they start to narrow down in their thirties because the other big thing that rather forces this. Narrowing down is if you reproduce and as all those who have young children will remember, babies and social life, absolutely incompatible.

If it takes a long time to emerge from it.

Dunbar's Number: Pt 2 - Age

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