Don't Believe Facebook; You Only Have 150 Friends According to "Dunbar's Number," human beings have enough mental space to keep track of only 150 meaningful relationships. But how deep can those bonds be when friends, family members and co-workers are scattered all over the globe?
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Don't Believe Facebook; You Only Have 150 Friends

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Don't Believe Facebook; You Only Have 150 Friends

Don't Believe Facebook; You Only Have 150 Friends

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RACHEL MARTIN, host: There's a famous story among sociologists. It's about Bill Gore, the guy who founded GORE-TEX.

ROBIN DUNBAR: When Bill Gore set the company up, he set it up in his backyard, literally, a little home company.

MARTIN: That's Robin Dunbar.

DUNBAR: Professor of evolutionary anthropology at the University of Oxford, England.

MARTIN: And he says after a while, Bill Gore's company got bigger and bigger. Then one day...

DUNBAR: One day, he walked in and...


DUNBAR: ...he simply didn't know who everybody was. And it was his kind of gut instinct that the bigger a company got, people working for the company were much less likely to sort of work hard and help each other out within the company, and do all these kind of things that make a company go.

MARTIN: So Bill Gore did some counting, and he figured that after about 150 people, folks at GORE-TEX just couldn't keep track of each other. It was just too many faces. It destroyed the sense of community. So he decided...

DUNBAR: Thereafter, whenever they needed to expand the company, he would just build a new factory, sometimes right on the parking lot next door.


MARTIN: The factories were capped at 150 people, and Bill Gore found things worked better. People knew each other. They worked better together.

DUNBAR: Everybody had the same label on their jacket that said GORE-TEX Associate, and that was that. Everybody knew who was who - who was the manager, who was the accountant, who made the sandwiches for lunch.


MARTIN: Robin Dunbar has spent a lot of his career studying this idea that after 150 people, human beings have a much harder time keeping track of each other. A hundred and fifty, in fact, is known among sociologists as Dunbar's Number, because it turns out when you start looking, that number pops up in all sorts of places.

DUNBAR: Hutterites, for example, up there in the Dakotas.

MARTIN: Each Hutterite community?

DUNBAR: Very traditional life.

MARTIN: About 150 people. Same with the Amish.

DUNBAR: A hundred and fifty.

MARTIN: Hunter-gatherer communities?

DUNBAR: Bushmen from Southern Africa, American Plains Indian, North American Indians, 150.

MARTIN: Even in militaries around the world, a typical company...

DUNBAR: They have exactly this kind of structure.


DUNBAR: ...a hundred and fifty, 150.

MARTIN: The reasons may stem from our primate ancestors, Dunbar says. In smaller groups, primates could work together, evade predators. And today, 150 seems to be the number at which our brains just max out on memory. But what does all this mean if you're not Amish, or the CEO of GORE-TEX? We spoke to David Dobbs about this. He's a writer and blogger for Wired magazine. And he says when you think about the way most people live now...

DAVID DOBBS: It's different. We developed this sort of 150 limit of relationships we could handle well at a time when most of those people would be the people who lived geographically close to you.


MARTIN: That means if you're anything like David, you probably don't live in the town where you grew up. He lives in London.


DOBBS: Hello, Dad. This is David. Can you hear me?

DOBBS' FATHER: Great to hear your voice after such a long time.

DOBBS: Yeah, I know. I've been rather...

MARTIN: But David's dad still lives back home in Texas.

DOBBS: : Do you have another chicken?

DOBBS' FATHER: We have a chicken.

DOBBS: When did you get the chicken? You used to have Thelma and Louise. What's this one's name?


DOBBS: Betty Sue. That's a good Texas name.

MARTIN: These days, maybe your siblings did the same thing - left home, went to college across the country, then moved to yet another place for work.

DOBBS: Cynthia?

CYNTHIA: How are you doing, bro?

MARTIN: David's sister Cynthia lives in California.

DOBBS: Talked to dad a little while ago. He did tell me about his chicken, who's his only company right now.

CYNTHIA: Oh. Where's Kathy?

MARTIN: Then there are close friends who live outside your area code.

DOBBS: You been fishing lately, is that right?

DICK: I've been getting in some talking about fishing.

DOBBS: OK. Well...

MARTIN: That's David's best friend, Dick, in New Hampshire.

DOBBS: I miss you, buddy. I'll see you soon.

DICK: Bye.


MARTIN: And there are old friends it's hard to stay connected to.

DOBBS: Hi, Mary Lee.

MARY LEE: Hey, Dave.

DOBBS: Where do we start? How have you been the last 10 years?

LEE: Oh, gosh, the last 10 years...

MARTIN: Professor Robin Dunbar says it's tough keeping up.

DUNBAR: This is very unlike traditional small-scale societies, and I think it's much harder to keep those relationships working and good when they're that distributed - because that's why Facebook and other social networking sites really kind of work for people.

MARTIN: But according to Robin Dunbar, only 150 of the 800 friends I count on Facebook are really my friends. And not only that, David Dobbs says...

DOBBS: It struck me that looking after these things is a very complicated business, particularly in the information economy. If you're an information worker like...

MARTIN: In other words, how do you balance your 150 friends and family members in a global economy, when more jobs now require social networking? Robin Dunbar says it actually depends on the size of the place where you work. If it's a smaller company...

DUNBAR: Under - say, 500 people, there's a very strong tendency for your workers - or colleagues, as it were, also to be your friends.

MARTIN: Workers in a big corporation, on the other hand...

DUNBAR: So the company size gets up into the thousands...

MARTIN: Those people tend to have more friends outside the place where they work. And one final thing about Robin Dunbar's research: He says while modern society does, in fact, make it hard to hang on to friends who aren't geographically close...

DUNBAR: This, incidentally, doesn't have any effect on family relationships. Family relationships seem to be very stable, no matter how far away you go.

DOBBS' FATHER: Thanks very much for calling, David.

DUNBAR: They love you when you come back.

DOBBS: You bet, pop. Kiss Kathy for me. And take care. I love you.

DOBBS' FATHER: I love you. Bye.

DOBBS: OK. Bye-bye.



MARTIN: David Dobbs. His blog at Wired Magazine is called "Neuron Culture." We also spoke to Oxford professor Robin Dunbar from his home in England.

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