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How many friends do we really need to be happy?

On my quest for more meaningful friendships, I took a hard look at the people in my life. Then things got a little weird.

john s. dykes for the boston globe

I removed some artwork from a wall in my office at home, got a fresh Sharpie and a stack of Post-it notes, and started writing down names.

I began by picking through the contacts in my phone, then scrolled through my 1,335 Facebook friends. Many of the choices for names to put on the wall were easy. My wife. My parents. Grandma. My younger brother in California. The Danimal, my freshman roommate. Two girls I’d first met in fourth grade. My sister-in-law, most days. Six people I’d met through my kids. Twenty-three journalists, which is way too many, including six from grad school. Seven people I grew up with in Southie, which is definitely too many. Eight people I went to high school with and eight people I went to college with. Five were former roommates. Thirty-five were women. Seven were people I met when I wrote a story about them.


Several of the choices surprised me — people who felt so random yet I lit up immediately at the sight of their names. More surprising was the ease of the omissions, how quickly I was able to look at the name of a person I knew, often very well, and know I did not find them very interesting. Still surprising was that I did not feel like I was doing anything wrong, for I could definitely say I liked nearly all of the people whose names scrolled past my eyes. I’d stop and say hello if I ran into them in a bar. But would I be embarrassed to join them for a drink?

That was one of Robin Dunbar’s ways of drawing the line at whether you have a meaningful social relationship with another human. And the number of meaningful relationships you can sustain was limited, he said, to 150. Dunbar’s number, as it is known, is one of the most discussed theories in social psychology — the work of an Oxford professor who has spent a long career doing research in all corners of social evolution. Everywhere I read, Robin Dunbar’s name appeared again and again because he asks the best questions.


The number 150 was not a theory but a calculation, based on the size of the neocortex. In studies of primates and other mammals, Dunbar found that the ratio between the volume of the neocortex and the volume of the total brain could accurately predict the size of the animal’s social group. When he applied that math to the neocortex of Homo sapiens, he came to the number 150.

Dunbar’s number came out in the late 1980s during a hot time at Oxford for evolutionary thinking, when young scholars like Richard Dawkins were arguing that our genes are selfish, and that evolution and natural selection are not the stories of an organism but the story of its DNA competing to live on in future generations, since nearly every bit of heritable information we pass on to the next generation happens in a chemical instant at the moment of conception.

Dunbar proposed what is now known as the social brain hypothesis, which argues that human intelligence evolved primarily as a means of surviving and reproducing in a large group. The patterns of behavior we inherit from our ancestors have been molded by this long game of survival of the fittest just as much as the bodies they are housed in. We are born with rules that guide us.


Dunbar proposed that every person had their own social fingerprint, but in general most people had a group of 150 that broke down thus: Five “very close” friends, plus your romantic partner if you have one. Then you have 10 “close” friends, who combine with the “very close” friends to fill out what he called your “sympathy group” — the people who always come to your birthday and cry at your funeral. From there, you have 35 people who are in the middle ground between close friends and acquaintances, and then you have about 100 acquaintances.

We of course know far more people than that. Statistically, we are able to put names to faces for about 1,500 people, but constraints in time and bandwidth limit us to right around 150 “friends,” Dunbar argues. I’m still not sure if 150 sounds like a lot or a little, but I do know that to keep up with that many required humans to take giant leaps in how we handled social grooming. In nonhuman primates, grooming is done one-on-one through physical touch, which is inefficient. Humans developed music and dance and storytelling and laughter as ways to connect with more than one person at a time. Dunbar found laughter to be exceptionally potent, delivering an endorphin hit three times as effective as physical grooming. (He also found the optimal laughter group size is three people. For a conversation, the number is four.)


Dunbar’s great questions came with great answers, but by putting numbers on fluid social actions, he was practically daring people to prove him wrong. Yet decades later, that has not happened; instead, people have continued to find anecdotal evidence of 150 popping up in all sorts of places, from the size of military companies dating back to the Romans to the average number of Christmas cards Brits send out each year. It’s easy to see this number if you’re looking for it, of course. Many corporations have successfully adopted it as a mantra in their organizational structures. But the best supporting case I’ve heard comes from the fact that 150 is the average size of a clan in the surviving hunter-gatherer societies.


‘I had taken a leave from my job at The Boston Globe to work on this book about loneliness, which meant I spent my days locked in a spare bedroom in my house, reading about loneliness and thinking about loneliness while engaged in the loneliest activity I know of: writing.’

MANY SCIENTISTS REMAIN conflicted about why we even need friends. Technically, you can survive without them. Many people do. More attempt it each day. But the theory that comes up most often to support popularity concerns the ability to assemble a squad when stuff hits the fan.

The concept of having a friend’s back, and knowing they have yours, is a sacred pact. It is the knowledge that in times of danger and crises you are not alone. What makes it so special is that it does not apply to every friend in the exact same way. There are only so many people you’d jump into a fight for.

I knew exactly who those people were because I’d written down their names on Post-it notes like a psychopath. But by defining who was worth fighting for, I had done something equally worthwhile: I had identified who was not. Letting go of problem relationships can be just as important for health and happiness, because they can literally infect you with their toxicity.


Since 1948, researchers have been tracking 5,000 people — and now their offspring — from Framingham, Massachusetts, in one of the most important longitudinal studies of health. Perhaps the most groundbreaking finding of that study is that it shows that it is not just germs that are contagious. There are measurable social contagions. Obesity is contagious among social networks, as is smoking.

You can probably see those pretty easily. But perhaps more surprising is that researchers discovered that things like loneliness are contagious. Having a lonely friend makes you statistically more likely to be lonely. But here’s the best part. Happiness is contagious in the exact same way.

So posting those names on my wall was as much about knowing who I cared about as it was about letting go of those whose problems were infecting my life. Once you know who to give a crap about, you can turn your attention to how to give a crap about them.

I began counting the names on my wall. It looked like a lot, if I’m honest, but as I hit 100 and looked ahead I got that tingly feeling that Dunbar was about to drain his shot.

One forty-eight. One-forty nine. One-fifty.

I dashed downstairs to go tell my wife about this strange stuff I’d been doing with a Sharpie — and also to make sure she didn’t call the police, because there aren’t too many sane people who cover their walls with Post-it notes that have names written on them.

When the goose bumps had worn off, I moved the names into groups. The largest grouping was the 23 journalists, which I again assure you is way too many, but I’ve been working for two decades and that’s what happens. Accidents of proximity. That’s the term I’d used in my original article in the Globe Magazine on the loneliness epidemic among middle-aged men to describe work friends, which inspired one of my work friends to declare to me that she was “offended!” I’ll admit it’s kind of an aggressive statement, but really all friends begin as accidents of proximity. There’s a word for those who are not accidents: “family.” Friends are the family you choose, and we can typically only choose from the people who are in proximity.

I stepped back and looked at the names on the wall from afar, then stepped in to again divide the data, this time along a simple, painful line — which of these people do I actively socialize with, and which do I need to work on?

I HAD TAKEN A LEAVE from my job at The Boston Globe to work on this book about loneliness, which meant I spent my days locked in a spare bedroom in my house, reading about loneliness and thinking about loneliness while engaged in the loneliest activity I know of: writing. I stared at a blinking cursor and a wall full of Post-it notes that I had convinced myself contained some sort of path to an answer. Outside my small window, winter had arrived and the world was freezing and dying by the second.

I read a lot of research. I put off reading a lot more. I made grand plans that I failed to execute, and grocery lists that I did, because leaving the house for the supermarket was my rare out-of-the-house-and-away-from-the-damn-computer activity. I also went to the gym quite a bit, which meant I walked in the door a blabbering Muppet of a man, one who had been reading dire news about our broken social connections and clearly needed someone to talk to.

My lonely brain had become consumed with the thought that loneliness was solvable if approached systematically and enthusiastically, but the Post-it notes on my wall clearly told the story of a man grasping for answers. I simply needed somewhere to go, something to do, and someone to talk to. I didn’t lack for friends; I lacked for a way to be friends with my friends on the regular.

One day, I dashed off a rambling e-mail to my town’s Board of Selectmen, explaining that I sought to rent a local cabin owned by the town for a “men’s group that meets on Wednesday nights.” I went on to explain that my crew would be men in their 40s, “dads who need to get up in the morning” — all of it a not-so-subtle attempt to make clear that we were, on paper at least, responsible adults who would not trash the joint.

I received a prompt reply informing me that the cottage was closed up for the winter. When I finally appeared before them a few months later, I was informed that between insurance and other fees, it would be way out of my price range. But when I arrived in the newsroom a few days later, I found a voicemail waiting on my desk phone. It was from one of the selectmen, a guy named Andy. His message was brief. He said he’d been thinking about my predicament and that he thought he might have the answer.

A few days later, on a Saturday afternoon, I went to meet Andy at his farm, and I spent the short drive with my fingers aggressively crossed, hoping I already knew where this was going. Andy was about a decade older than me, with a round, friendly face, and after shaking hands and welcoming me he picked up the story he had begun telling me over the phone. He’d grown up down the street, and as a kid he would come to this majestic farm — with its sweeping views of the Essex River snaking through the Great Marsh — and help care for the animals. But mostly, like all the kids in the neighborhood, he would play in the towering barn, which was built in the early 1800s and looks straight out of a New England postcard. When Andy was a kid, the barn functioned as something of an informal community center and the loft — which ran the entire length of the barn on one side — was like a clubhouse for him and his buddies.

Fast-forward a couple decades. He had done well in life and was just finishing building his “dream house” in a neighboring town. Then one night he was in a restaurant just up the road eating dinner when he heard that the family who had owned the farm for decades was going to put it up for sale. “I walked straight out the door, drove to the farm, and asked the family what they wanted.”

I followed him up the stairs to the loft, as he trailed some halfhearted apologies about how the place was kind of a mess because he pretended not to notice that his teenage daughter and her friends had parties up there. “You have to choose your battles,” he said.

When I got to the top of the stairs, the scene in front of me was not much. A couple old couches. Some beat-up chairs. It reminded me of a college apartment, the kind where there’s nothing much to break because everything is already broken.

It was perfect.

And the best part was that I didn’t really have to say anything. He knew it was perfect. He got it. He’d heard my entire spiel before the Board of Selectmen, where I’d gone through great pains to remove any idea that I was looking for a fraternity house.

And then he presented me with a fraternity house.


Billy Baker's upcoming book "We Need to Hang Out."

LATE ONE MONDAY NIGHT, I drove away from my house with a dozen handmade invitations sitting on the passenger seat next to me. On each of the envelopes I had written “Top Secret” and “For Your Eyes Only.” Inside was a hand-drawn map to the barn, along with a date and time. Why did I do such a thing? Because it’s nice to think your life is a movie. The fact that it was currently pouring rain outside only made my mission feel more cinematic.

I could have invited the fellas to my new Wednesday Night thingamabob in any number of other ways. But I had chosen this over-the-top route because I needed some comic distance from what I was actually saying, which was “I only kinda know you, but I really like you and want you to join my new club so we can be friends forever.”

I pulled up to the first guy’s house, opened his mailbox, and as I flipped through my invitations looking for the one addressed to him, I stopped for a second and asked myself if I was absolutely sure, because there was no going back after this. I was not questioning whether or not I wanted to commit to the concept; no, I was questioning the 12 names on the envelopes in my hand. Because from the moment I became convinced that this fraternity would be the answer to all my problems, I had been performing the complicated mental calculus of who I would actually invite to my little experiment.

I had started with my “best friends,” a couple guys from high school as well as some other names from my youth — fellas I loved and still felt close to because of our history but never really saw much anymore. I took a step back and stared at the dozen or so names on the wall — yes, I was back with the Post-it notes again — and took a moment to relish just how great it would be to get that crew together in the barn on the regular.

But the more I looked at their names, the more I knew that something was wrong. I loved each and every one of them like a brother. But you can’t go home again.

We would be boys forever, but we were not boys anymore. Each of us had gone down a different path, to a different place, and we were no longer a central part of one another’s ecosystem. And that was OK. That was life.

I felt no guilt as I removed their names from my wall. They were the definition of friends for life. But I needed friends for my daily life.

So what I felt in that moment was a nervous excitement, a vulnerability, because I wrote down a dozen new names and placed them on my wall, and each of them was a recent friend. I hadn’t known any of them for more than seven years, when we moved from the city to Cape Ann. Most I had known for about half that. Some I didn’t know well at all. But the one thing they all had in common was that they were part of my new ecosystem and I felt some sort of connection to them, some ineffable spark that signaled that maybe, just maybe, we were meant to be more than simple acquaintances.

Yet as I drove around that night in the rain with their invitations, I was unsettled. I had spent this entire journey trying to get the band back together, but it had done almost nothing to integrate friendship back into my daily life.

Now I was attempting to start a new band.


Billy Baker, a Boston Globe staff writer, can be reached at billy.baker@globe.com. This essay was adapted from his forthcoming book “WE NEED TO HANG OUT: A Memoir of Making Friends.” Copyright 2021 by Billy Baker. To be published by Avid Reader Press, an Imprint of Simon & Schuster, Inc. Printed by permission.

Billy Baker can be reached at billy.baker@globe.com. Follow him on Instagram @billy_baker.