We pay a lot of attention to our romantic relationships. Whether it’s selecting a mate or maintaining one’s relationship with them. Apps make millions of dollars promising to streamline this process. Hundreds of books are published every year telling us how to do it better. And don’t get me wrong: long-term romantic partnerships are hard, no doubt. But that difficulty is not lost on us. Multiple industries are designed around giving us tools to help overcome it. It’s something we spend a lot of effort on trying to do better.
But what about friendship? We also know it’s important, sure. But we don’t give friendships the same treatment as our romantic relationships. There are no holidays meant to carve out time to express appreciation toward our friends. A few books are written each year about Platonic friendship, but far fewer than those about romantic relationships. And yet friendship is one of the most important aspects of our lives. In some ways, it’s even more important than the handful of long-term romantic partners we’ll have in our lifetime.
This, at least, is the claim made in a recent book by my guest today, Robin Dunbar. Robin is a legendary figure within social and evolutionary psychology. He is perhaps best known for the idea of Dunbar’s number: the number of stable, close relationships an individual can maintain is reliably right around 150. But from the broadest level, the major question of Robin’s work asks, “What do our circles of friendships look like? What should they look like?”
The way that I’ve come to think about the core of Robin’s research is that we all face the same fundamental problem: limited resources. Specifically, limited time. Each of us has to choose how we’re going to allocate our limited time to work, family, hobbies, exercise, friendships, and all the other activities and pursuits which we’d like to do. Often when our temporal resources become scarce, the first thing to get cut are our friendships. Friendships don’t come with urgent deadlines. We know our friends—our true ones at least—will forgive us if we don’t see them as often as we’d like. After all, we’ve both got a lot going on. What all this adds up to is that the disintegration of friendships over the course of adult life feels all but inevitable.
And yet—most of what is known scientifically about friendships is not generally discussed. For example, you have probably heard of Dunbar’s 150 figure. But that’s not the only important number. There are layers here. Essentially, Dunbar’s research shows there are concentric circles of friendships, beginning with your five most intimate friendships, then fifteen close friends, fifty good friends, 150 general friends, then 500 acquaintances, 1500 known names, and 5000 known faces. There’s a mountain of evidence showing that these numbers are consistent across cultures—even with the advent of social media.
In other words, there’s a connection between the quantity of friends we have at any given level and the quality of relationship we should have with them. Maintaining this balancing act has huge consequences for us across all aspects of our well-being.
Personally, I believe the acquisition and maintaining of friendships is one of the greatest challenges of adult life. It’s especially difficult in a post-pandemic world, where we’re less tied down to living in a single place and more free to work in other locations. The cost of this flexibility is increased loneliness. We find ourselves adrift from the usual social rhythms of life which we humans are used to. But unfortunately, the problem of solid friendships is one we spend almost no time trying to solve.
Robin’s book is Friends: Understanding the Power of our Most Important Relationships. It’s out now.
[This interview has been edited and condensed. Full conversation available via the podcast.]
In the beginning of your book, you present your thesis on why friendship matters. A lot of the evidence you marshal has to do with some pretty convincing studies. Could you say a little bit about what those studies show, and present that argument for why friendship matters so much?
One of the big surprises of the last 15, maybe 20, years has been the absolute deluge of studies—some of them short-term cross-sectional, many of them long-term studies— showing that the single best predictor of your mental health and well-being, your physical health and well-being, and even how long you live into the future is determined by one factor and one factor alone. And that’s the number and quality of close friendships you have.
So typically, this number would be about five people. In collaboration with a bunch of people in Denmark, we did a big study across 13 European countries. We looked at the likelihood that somebody would develop symptoms of depression in the future, and asked what factors predicted that development. What seemed to preserve you from falling prey to depression in the future was having about five close friends and family. So if you had fewer than that, you’re more likely to develop symptoms of depression. And if you have more than that, you are more likely to develop symptoms of depression.
But there was an alternative. And that was volunteering in a social context, or helping out in a charity shop, or being involved with helping running the scouts, or helping with flowers at your local church, or being involved with a political party—any of those kinds of things that were essentially social activities. So if you had about three of those that was as good as having about five friends, and they were kind of interchangeable. But you couldn’t add them together. You couldn’t have five friends and three voluntary activities, and hope to live forever—because you wouldn’t.
And the reason is very simple. It’s the reason why having more than about five or six friends isn’t really very good for you. It’s that you spread yourself too thinly among these people involved in the social environments. So having a smaller number where you can really get to know the people and be engaged with them—that’s what’s beneficial. If you try and spread yourself too thinly, you don’t create relationships of the quality that’s necessary to buffer you against things like depression.
One of your core ideas has to do with what you call the seven pillars of friendship. These are: having the same language, growing up in the same location, having the same educational and career experiences, having the same hobbies and interests, having the same worldview, the same sense of humor, and the same musical tastes. It’s clear how these can play out in face-to-face interactions. But what does this mean for remote friendships—the kind of modern friendships we try to maintain digitally across distance?
Okay, so the evidence is both good and bad. Because there’s no such thing as Nirvana in the world, everything has a benefit and a drawback. The upside is that, from our work, it seems that different media of interaction—ranging from face-to-face, Zoom video calls, telephone, texts, or emails—are kind of substitutable in terms of how many friendships they allow you to maintain. Because we see exactly the same layers, with exactly the same frequencies of contact, in data from all of these environments, suggesting that they all work pretty much in the same way, and are subject to the same limitations.
In other words, just because you use Facebook doesn’t create the opportunity to have 1000s of friends—true friends. In your social network, yes, you can be connected to 1000s of people on Facebook. But you’re connected to 1000s of people in the everyday world. Some of them we call them friends and family. Some of them we call acquaintances. Some of them we call just people we know—we don’t know much about them, but they’re part of our social environment. For people who have a very large number of friends on Facebook, a lot of those are in that category.
But it seems that there’s still something missing in terms of our satisfaction of relationships in those kinds of environments—like Facebook or Zoom—compared to those we have face-to-face. And that seems to be primarily because what’s missing is touch. And we use touch constantly with our close friends and family, perhaps out to the 50-person layer of our social network. We don’t go around hugging strangers usually, or anything like that. We’re very circumspect in who we do it with. But for those, whom we regard as good friends, intimate friends, we do an awful lot of very casual—what’s generally referred to now as soft taps and hugs, strokes, pats on the knee, perhaps around the shoulder, all these kinds of things goes on constantly if you just watch people in an informal social environment. And that seems to be very important in creating this sense of relationship quality.
I sometimes say, if you want to know how somebody really feels about you, then see the way they touch you—stroke, pat, hug, whatever. This gives you a better sense of what they mean, or what you mean to them, than 1000 words that they might say to you. And that’s because words are slippery things. We’re very good at saying what we don’t mean and making it sound extremely plausible. But it’s very difficult to lie in the way you touch somebody, perhaps because it’s so, so intimate. So there are those kind of drawbacks, which clearly Zoom and Facebook and anything else you can think of are never quite going to overcome. I just don’t see how they can do it.
You recently co-authored a paper in Nature Human Behaviour on social isolation and the brain in the pandemic era. Certainly, there was something anomalous with social life during the COVID years. But with the post-pandemic switch to remote work and outsourcing more and more of one’s social interactions to online—all the drawbacks, such as lack of touch—what do you think the role of loneliness is in modern life? And how does that play out for us today?
John Cacioppo, the late neuroscientist, pointed out that the feeling of loneliness act as an alarm bell. The alarm means you’re not meeting enough people: get out and do something, or go find a friend. It’s not very good for you to experience loneliness, because it exposes you to the risk of increasing downward spiral of depression. And that has knock-on consequences for physical illnesses, as well as mental health and well-being. So it really is kind of the signal or reminder to for you to try and do something to restore your social environment.
The problem is, of course, that’s not easy to do. We’ve suffered from a pandemic of loneliness, particularly in the 20-somethings age cohort, for the better part of 30 years now. It’s really surfaced in the big cities in terms of people having their first job after leaving university. Your whole life up to that point has basically been cocooned in a ready-made social environment at school. You had a bunch of people who would make perfectly decent friends. You’re used to having potential friends on demand all the time. You go to university and live in student halls or something like that—it’s kind of bumpy to begin with, while you just get your feet under the table. But very quickly, you build up friendship circles, because they’re there 24/7 and you’re seeing a lot of them.
Then suddenly you graduate. You get a job in London, New York, or Los Angeles—wherever. And you don’t even know where to go to meet people. All the people at work who are the only people you meet regularly already have their sexual lives sewn up. Some of them have families, and they want to get back at five o’clock. Even the ones that don’t have families, they’ve already got their friends and circles and the things they do on an evening with them.
So we’ve had this tendency for the newcomers in businesses or government departments or whatever to be thrown in completely at the deep end with nowhere to go, and it’s caused this pandemic of loneliness. It’s not good for employees. And it’s not good for employers. Everybody’s been looking at this going, “We’ve got a problem. What are we going to do?”
One solution is to make the work environment a social environment, which is what they used to be. Until perhaps 50 years ago, when new management practices came in, most big companies had their own social clubs, their tennis clubs, theatre clubs, football clubs, where people hung out after work. And that created this sense of belonging, and a sense of community. And of course, when you came new to that company, or, or business or whatever, you were thrown straight into this social environment where it was safe, everybody knew everybody else, everybody was on the same page. They all shared a lot of their seven pillars of friendship in common simply by being employees in that same environment. And it was a good place to make friends. Some Silicon Valley companies have done that in an encouraging way. But it’s not the norm. We can’t let it continue, this widespread loneliness. Because it’s not good for business. And it’s not good for individuals.
I’d like to ask you about the difference between a strong romantic relationship and a strong friendship relationship. What does a romantic relationship require that friendship does not?
Not a lot. In terms of emotional content, they seem to be very similar. Obviously, romantic relationships tend to have a sexual component to them—which is, by and large, absent in Platonic friendships.
But there are important gender differences here, particularly with our closest friends. What you find is that women, in particular, commonly have a” best friend forever,” who’s another woman, as well as the romantic partner. Occasionally, about 15% of the time, there’ll be another male—a male rather than a female—but most of them typically have a best friend who is a female. The opposite is the case for guys. They will tend to have a male best friend, sometimes a female best friend. But the quality of those relationships is very, very different to the quality of best friends that you find with female “best friends forever.” They’re much more casual, and they tend to have been around a lot longer. They tend to date back to kind of high school or college period. If you look at people in their mid 40s, they’ll say, “Yes, I’ve known him since we were at school together, that’s my best friend.”
In contrast to these kind of best friends, Platonic friends tend to be much more recent. Best friends are more stable than both Platonic friendships and romantic partners—which tend to have a lot more turnover. So female best friendships and romantic partners, they’re very fragile in that sense. They’re based on deep trust, and therefore you tolerate infringements of that trust. Until it happens once too often, you’ve had enough and then that’s it. And then you have catastrophic breakdown. Whereas in general, other kinds of friends and men’s best friends tend to just drift apart.
One final question. What are three books that have most influenced the way you think?
Actually, I’m going to point in a slightly different direction in terms of what influenced me and offer up the following three.
One is a Victorian spoof. Not too many people know about it. It’s called Flatland. And it was written by a couple of guy masquerading under the pseudonym “A Square.” It is a kind of spoof on hierarchies in society. So it imagine the world consists of different kinds of dimensions. So you’re a two dimensional person, and you enter into this world where one dimensional people are dots and three dimensional people are cubes—and you’re trying to negotiate this strange social world. It’s a reminder that your particular viewpoint or your particular culture is not necessarily the ultimate good thing. You should take other cultures at face value and enjoy them, get to know them and understand them—in the sense of how the square would have to understand the cube world or the one dimensional world.
As a second book, I’m going to pick T.S. Eliot’s poetry. I actually studied Eliot in high school for my high school final exams (A Levels as we call them here). I think he’s just the most amazing poet who ever came our way. In many ways: mentally complex, and extremely well read, and immensely deep.
As the last choice, I’m actually going to pick something I’m sure nobody’s ever heard of. It’s the Irish writer Brendan Behan’s semi-autobiographical book called Hold Your Hour and Have Another. It just has that Irish flow and fun—that sense of fun and “life is a gas,” as the as the saying goes. It’s just wonderfully well-written little vignettes on his experiences in life. Great guy: he died very young, at the age of 41. Same age actually as the other greatest poet ever, Dylan Thomas, the Welsh poet, who I might otherwise have included, because his sense of observation is absolutely extraordinary. T.S. Eliot is more internal and intellectualizing and looking at himself. Dylan Thomas’s observations on the foibles of other people is just unbelievable in his way with words. It’s just beautiful. It’s absolutely fantastic stuff. So you get four for the price of one.
Robin Dunbar, thank you so much for taking the time to talk today.
You’re very welcome. It’s been great fun.
#104: Palentine's Day (feat. Robin Dunbar)