The Invention of Friends (Dunbar’s Number)

Vsauce! Kevin here. Your Vsauce2 friend. Your college friend. The friend of a friend you met at a party,
a family reunion, a concert, an online forum dedicated to Japanese role playing games. But am I really your…friend? Probably not. Why? Because we don’t like the same music or
movies? Because you wouldn’t invite me to your wedding? No. Because your brain is full. While studying primate social systems, psychologist
Robin Dunbar found a correlation between the size of the neocortex and the size of the
average social group. The larger the neocortex, the larger the group
size. By extrapolating his findings and applying
them to humans, he arrived at a cognitive limit for the amount of complex, mutually
affectionate social relationships a person’s brain can handle. A research guideline for the number of real
friends you can have. A literal “friend zone.” Of 150. Dunbar’s Number. So… who are all these Facebook friends I’m
not actually friends with? By pooling everyone in your social network
into one tub labeled “friends,” Facebook oversimplifies your relationships. Your mom, your best friend from high school,
and your brother’s former boss you met once at a company picnic are all incorrectly assigned
the same level of intimacy. Your actual social network would look less
like a tub and more like a series of buckets. High school friends, neighbors, work friends
from various jobs, nuclear family, extended family, online friends, family friends, people
you literally don’t know how you became Facebook friends with. You know these are separate hubs because mixing
them gets awkward, it’s why seating charts at weddings get complicated. Your college buddies and your grandma Tilly
not only have little in common, but they’re likely friends with a different… you. And the intimacy of these friendships occur
roughly in concentric circles separated by a factor of three. You probably have about 5 of your closest
friends formally referred to as your support clique, people you speak with every week. In fact, 80% of phone calls are made to the
same 4 people. About 12-15 can make up your sympathy group
— people who would be devastated if you died. You can probably handle about 50 meaningful
relationships and a maximum of 150 currently active friendships. Here’s the weird part. Dunbar calculated this human friendship limit
based on neocortex size in relation to primate group size. It turns out it’s like the shadowy secret
of human cooperation. Oooooh! No, really. A study of the twenty tribal societies with
available census data showed a mean clan group size of 153. Dunbar and fellow evolutionary anthropologist
Russell Hill examined the exchange of Christmas cards in the U.K. and found a maximum network
size of 153.5. A 2008 survey by The Knot Wedding Network
of over 18,000 brides revealed an average wedding guest total of 148. The Roman army during the Republic utilized
a fighting unit called the maniple with 130 to 140 soldiers and officers, while in modern
militaries a company tops out at about 150. Middle Eastern Neolithic villages dating back
to 6,000 BC usually populated between 120 to 150, while the Domesday Book of 1086, one
of the oldest population surveys, commissioned by King William The Conqueror for tax collecting
purposes reveals an estimated English village size around 150. Even into the 18th century the average English
village had about 160 residents. Today, the Hutterite and Amish communities
split if the group exceeds 150. Bill Gore split his Gore-Tex factories by
150 to keep his employees functioning in personal, cooperative relationships. A 2011 study of 1.7 million Twitter users
found they maintain a stable relationship with 100-200 individuals. The average number of Facebook friends is
between 150 and 200. When an NFL team wins the Super Bowl, guess
how many rings are awarded? 150. Wait, so if every person outside my 150 is
just some sort of casual acquaintance, then what’s a friend? And why do we have them? And do we need them? And well, that’s enough questions for no,
Billy. Just relax. Relationship quality and the cognitive complexity
involved in managing friendships means it’s not just memorizing human trivia like how
one person relates to another and how they both relate to you, that Judy’s favorite
food is beef stroganoff, or the latest gossip about Stan dumping Sarah for Sally because
Sarah snuck out with Steve Sassleberry on Saturday and they smooched! A friend requires the presence of a social
bond like routinely removing ticks. The purpose of mutual grooming in primates
is not just about picking parasites, but also about reducing stress and forming and maintaining
social structure. Not for fun, for survival. The social intelligence hypothesis states
that the need for understanding and managing relationships is the key identifier separating
primates from other animals. And there’s a correlation between group
size, complex social worlds, and relative size of the neocortex, the layer of the brain
responsible for cognition and language. The need to live in larger groups for the
survival of the species may have driven humans to develop the largest relative neocortex
on the planet. I’m able to form words and communicate with
you. You clicked on this video to watch and listen
to me. Our brains evolved to satisfy our need to
survive, which required forming relationships with each other. Look, if we’re gonna live on the ground,
in open habitats, and there are snakes, lions and dingoes out there, we better have each
other’s backs. And probably a pointy stick or something. But the internet has made practically the
entire world our social habitat. So how do we categorize, sort, build and maintain
relationships with everyone we’ve ever met — and everyone we’re ever going to meet? Social media has allowed us to expand our
access to casual relationships and to build our network of loosely-known acquaintances. But analysis of Facebook friend surveys showed
the inner layers of an individual’s online social network just reflects the size of it
offline. The internet isn’t allowing us to pass the
limit of Dunbar’s Number. Friendship requires an ongoing mutual connection
— it’s not just a voyeuristic one-way relationship with your favorite YouTuber even though you
feel like you know everything about them. Phil DeFranco isn’t going to pick you up
from the airport at 3 o’clock in the morning. What? I’d totally pick you up from the airport. Wait, really? No. Oh. It’s important to note that the specific
150 number is not a hard and fast cut off, but a guideline for the cognitive abilities
required to track individual traits and preferences in complex social relationships. Some people may have a limit of 100 while
others can maintain up to 250 active friendships. And Dunbar’s Number is not a suggestion
for how many total friends you should have. You could have two and that’s totally fine
– you just can’t have more than your limit. It’s not just some memory barrier, a Jeopardy
champion can’t magically juggle 900 affectionate relationships, it’s also about the time
required to invest in a friendship to maintain an emotional interpersonal link. We have a fixed amount of emotional capital
we can spread out among a bunch of people or to invest more heavily into a smaller amount. And the time needed to keep relationships
going is what can turn an old best friend into just somebody that you used to know. Like that song. Somebody that I used to know. What’s changed about living in a time where
you can have 5,000 Facebook friends isn’t the number of people you can be friends with,
it’s the number of people who could be your friend. By opening up communication to the world,
we put life preservers on real friendships of the past as we swim deeper into a sea of
people we’d never have been able to meet before. And it’s changing how we do… ”I do.” Marriage was typically a social or economic
union arranged or sanctioned by families to bolster their survival. According to historian Stephanie Coontz, for
thousands of years marriage had very little to do with the individual relationship between
the bride and groom — it was really a way of turning strangers into relatives. A way of sticking new people to your social
web. Of integrating new balls into your ballpit. Today in the U.S., a third of marriages start
online. I’m sure many of you have close friends
you only know from a distance. By breaking down barriers of time and space,
we’ve unlocked meaningful connections unparalleled in human history. For thousands of years we were tethered to
and maybe even evolved to maintain relationships with the roughly 150 people we happened to
be born around and the families we married into. You were born in that social ball pit. Now there over 3 billion people connected
to the internet ready and waiting for a place in your life. A spot in your 150. Which doesn’t seem like much. Does it? Until you realize how amazing it is to share
your banana with a stranger. While chimpanzees will kill chimps outside
their social groups for resources, a Duke University study found that bonobos will share
food with strangers in order to expand their social network. Bats, dolphins, elephants and many primates
share with members of their own group, but the bonobo is offering up banana slices to
total strangers over members of their in-group in the hopes of making a friend. The human propensity to share has long baffled
us from an evolutionary perspective. Why give your banana to a stranger? But it now seems at least one other species
has seen the survival benefit in finding new friends. Anyone who’s faced personal hardship knows
how life-saving those friends can be. There’s a sentiment regarding friendship
that’s been passed down for millennia, from Aristotle’s successor Theophrastus to 19th
century British literary critic John Churton Colllins: “In prosperity our friends know
us; in adversity we know our friends.” And whether you have two, ten or 150, those
friends you know when facing adversity, when things aren’t going well, are forged with
a bond so rare, it’s millions of years in the making. Want a banana? And as always – thanks for watching. So at the end of my video on the Invention
Of Blue I featured an animated gif from the ludicrously talented Kidmograph. Well, he has a class on Skillshare that’ll
teach you how to make 80s-inspired animated gifs. Skillshare has over 17,000 classes in design,
video editing and more. An annual subscription is less than 10 bucks
a month and the first 200 people to use the promo link in the description get their first
2 months for free. So check out what Skillshare has to teach
you out check out this playlist for more Vsauce2 so you can keep learning about being… human.

100 thoughts on “The Invention of Friends (Dunbar’s Number)

  1. Yeah I only have like 37 I think but if they are meaningful that I would go out of my way to just have a good conversation or play video game I would say 23 now I am thinking and maybe I don’t need many friends because I have quality over quantity

  2. I really would want to meet a person that has like more than 100 friends I don’t how she could survive I maybe have 23 but it’s kinda weird for me the idea of having some many friends you can’t even keep up with there lives

  3. Key video takeaways: Marriage is a way of integrating your balls into someone's ball-pit, and it's amazing to share your banana with a stranger.


  4. That little circle of balls you did with the 5 support clique and 15 sympathy group… Does that NOT include your family or does it? I live with my parents and sisters but theres more "friends" that i talk to on a weekly basis. Curious cause I'm trying to figure out mine 🙂

  5. Why did i watch this?
    I have 1/150 friends i have a long way to fill the list up

    Can u be my friend btw?… yes im talking to u … help me get this list full 😊

  6. For some reason, the South Florida music community doesn't seem to follow this pattern. Professional or not, if you play an instrument or sing, you're in, and oddly enough, we not only remember each other, we are extremely supportive of each other. For example, I have over 700 Facebook friends, 85% of whom are musicians; I remember their names, what they play, where they live, their familial and relationship statuses, what they look like, where we met, their best songs, who writes their own songs, their children's names, etc. But it's not just me, we (the community) all do this. I'm less informed about the other 15% of my FB friends, and I've known some of them my entire life. I wonder if anyone can explain this.

  7. Hmmm… I only have about 7 people I really know and already forgot to hold contact with them…

  8. 2:20 Five closest friends huh? Well, there’s my Mom, Dad, brother, dog, and cat. Two seconds later oh, hmm, this is a hard one… well, I get five for free from the previous group, uhhh, my pet rabbit might notice if I died. Maybe my teachers? Except Mrs- you know what, I give up.

  9. I have a high IQ…probably able to handle a large friend group…but I generally can't stand people…so my circle is intentionally small…

  10. Besides the guild I'm in for a game, immediate family, and drug dealers, I have 0.

    Counting them, 13. Which is my favorite number. Cool.

  11. Hearing all these, i feel like an alien that has a presentation to give the next day to class about their favorite species

  12. I gotta admit, I just realized – especially with the "want a banana" at the end – how often I think to myself: "Hey, that person seems cool. I'd like to go drink a coffee with them."

    And I'm pretty introverted, myself. I believe a few online friends can count into my closer sympathetic group, but overall I really just have like 5-7 "good friends", excluding my mother who I probably have the best relationship out of my family with.

    There's an urge for me to increase that number, but usually the required sympathy and the drive to actually go out of my comfort zone only really happens with people that I will most likely never get to drink a coffee with.

  13. 150? I feel like the decimal point is 2 spaces too far to the right. (I just used all forms of that homophone in 5 words.)

  14. "What's a friend?
    Why do we have them?
    Do we need them?"
    Well you see Kevin, to answer it simply, No. We have friends because society expects us to. They are the people who eventually introduce us to pot.

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