TED2010
Nicholas Christakis: The hidden influence of social networks
Nicholas Christakis: Skriveni utjecaj društvenih mreža
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Svi smo mi ugrađeni u velike društvene mreže prijatelja, obitelji, kolega i drugih ljudi. Nicholas Christakis ispituje kako se mnoga svojstva -- od sreće do debljine -- mogu širiti od osobe do osobe, pokazujući kako vaše mjesto u društvenoj mreži utječe na vaš život na načine za koje niste znali da postoje.
Nicholas Christakis - Physician, social scientist
Nicholas Christakis explores how the large-scale, face-to-face social networks in which we are embedded affect our lives, and what we can do to take advantage of this fact. Full bio
Nicholas Christakis explores how the large-scale, face-to-face social networks in which we are embedded affect our lives, and what we can do to take advantage of this fact. Full bio
Double-click the English transcript below to play the video.
00:16
For me, this story begins about 15 years ago,
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Za mene ova priča počinje prije 15 godina,
00:19
when I was a hospice doctor at the University of Chicago.
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kada sam bio doktor hospicija na Sveučilištu u Chicagu.
00:22
And I was taking care of people who were dying and their families
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Brinuo sam se o ljudima koji su umirali, i o njihovim obiteljima
00:25
in the South Side of Chicago.
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u južnom dijelu Chicaga.
00:27
And I was observing what happened to people and their families
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Promatrao sam što se događa s ljudima i njihovim obiteljima
00:30
over the course of their terminal illness.
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tijekom smrtonosne bolesti.
00:33
And in my lab, I was studying the widower effect,
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I na svom institutu sam proučavao tzv. učinak udovca
00:35
which is a very old idea in the social sciences,
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koji kao ideja već dugo postoji u društvenim znanostima
00:37
going back 150 years,
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već 150 godina
00:39
known as "dying of a broken heart."
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također poznat kao "umiranje od slomljena srca".
00:41
So, when I die, my wife's risk of death can double,
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Po njemu, kada ja umrem, vjerojatnost smrti moje žene
00:44
for instance, in the first year.
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može se udvostručiti u prvoj godini.
00:46
And I had gone to take care of one particular patient,
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I brinuo sam se o jednoj pacijentici
00:49
a woman who was dying of dementia.
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ženi koja je umirala od demencije.
00:51
And in this case, unlike this couple,
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U ovom slučaju, za razliku od parova,
00:53
she was being cared for
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o njoj se brinula
00:55
by her daughter.
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njena kćer.
00:57
And the daughter was exhausted from caring for her mother.
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I kćer je bila izmorena od brige za svojom majkom.
01:00
And the daughter's husband,
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Suprug te kćeri
01:02
he also was sick
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je također bio bolestan
01:05
from his wife's exhaustion.
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zbog izmorenosti svoje supruge.
01:07
And I was driving home one day,
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Jednog dana, dok sam se vozio kući
01:09
and I get a phone call from the husband's friend,
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zove me prijatelj tog supruga
01:12
calling me because he was depressed
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da mi kaže kako je potišten
01:14
about what was happening to his friend.
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zbog toga što se dešava njegovom prijatelju.
01:16
So here I get this call from this random guy
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I tako imam poziv od ove nepoznate osobe
01:18
that's having an experience
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koja prolazi kroz iskustvo
01:20
that's being influenced by people
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da ljudi utječu na njega
01:22
at some social distance.
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preko znatne društvene udaljenosti.
01:24
And so I suddenly realized two very simple things:
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I iznenada sam shvatio dvije jednostavne stvari.
01:27
First, the widowhood effect
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Prvo, učinak udovca
01:29
was not restricted to husbands and wives.
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se ne ograničava na supružnike.
01:32
And second, it was not restricted to pairs of people.
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I drugo, ne ograničava se na parove ljudi.
01:35
And I started to see the world
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I počeo sam gledati svijet
01:37
in a whole new way,
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na sasvim novi način
01:39
like pairs of people connected to each other.
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kao parove ljudi koji se povezani jedni sa drugima.
01:42
And then I realized that these individuals
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I onda da su ovi pojedinci
01:44
would be connected into foursomes with other pairs of people nearby.
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povezani u četvorku sa drugim parovima ljudi oko njih.
01:47
And then, in fact, these people
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I da su u stvari svi ovi ljudi
01:49
were embedded in other sorts of relationships:
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povezani kroz razne vrste veza:
01:51
marriage and spousal
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brak i supružništvo,
01:53
and friendship and other sorts of ties.
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kroz prijateljstvo i na druge načine.
01:55
And that, in fact, these connections were vast
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I da su u stvari ove veze nepregledne
01:58
and that we were all embedded in this
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i da smo svi ugrađeni
02:00
broad set of connections with each other.
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u široki set međusobnih veza.
02:03
So I started to see the world in a completely new way
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I tako počinjem gledati na svijet iz skroz novog kuta
02:06
and I became obsessed with this.
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i to postaje moja opsesija.
02:08
I became obsessed with how it might be
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Postao sam opčinjen pitanjem, kako to
02:10
that we're embedded in these social networks,
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da smo ugrađeni u ove društvene mreže
02:12
and how they affect our lives.
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i kako to utječe na naše živote.
02:14
So, social networks are these intricate things of beauty,
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Društvene mreže su te fine lijepe stvari
02:17
and they're so elaborate and so complex
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koje su tako razrađene i složene
02:19
and so ubiquitous, in fact,
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i tako sveprisutne
02:21
that one has to ask what purpose they serve.
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da se moramo zapitati čemu ustvari služe.
02:24
Why are we embedded in social networks?
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Zašto smo svi ugrađeni u društvene mreže?
02:26
I mean, how do they form? How do they operate?
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Kako nastaju, kako funkcioniraju?
02:28
And how do they effect us?
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Kako utječu na nas?
02:30
So my first topic with respect to this,
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I tako moja prva tema u ovom kontekstu
02:33
was not death, but obesity.
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nije bila smrt, već pretilost.
02:36
It had become trendy
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Odjednom je postalo moderno
02:38
to speak about the "obesity epidemic."
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govoriti o epidemskoj pretilosti.
02:40
And, along with my collaborator, James Fowler,
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Zajedno sa svojim suradnikom, Jamesom Fowlerom
02:43
we began to wonder whether obesity really was epidemic
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zapitao sam se da li je pretilost odista epidemijska
02:46
and could it spread from person to person
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i može li se prenostiti sa osobe na osobu
02:48
like the four people I discussed earlier.
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kao ovo četvero ljudi o kojima sam maloprije govorio.
02:51
So this is a slide of some of our initial results.
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Na ovoj slici su neki moji početni rezultati.
02:54
It's 2,200 people in the year 2000.
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To predstavlja 2200 ljudi u 2000. godini.
02:57
Every dot is a person. We make the dot size
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Svaka točka je osoba. I veličina točke
02:59
proportional to people's body size;
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je proporcionalna tjelesnoj težini.
03:01
so bigger dots are bigger people.
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Znači veće točke su veći ljudi.
03:04
In addition, if your body size,
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I dodatno, ako je težina
03:06
if your BMI, your body mass index, is above 30 --
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to jest vaš indeks tjelesne mase preko 30,
03:08
if you're clinically obese --
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ako ste klinički pretili
03:10
we also colored the dots yellow.
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te točke smo obojili u žuto.
03:12
So, if you look at this image, right away you might be able to see
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I već prvi pogled na ovu sliku vam pokazuje
03:14
that there are clusters of obese and
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da postoje skupine pretilih
03:16
non-obese people in the image.
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i nepretilih ljudi na slici.
03:18
But the visual complexity is still very high.
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Ali vizualna složenost je još jako visoka.
03:21
It's not obvious exactly what's going on.
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Nije baš najjasnije što se događa.
03:24
In addition, some questions are immediately raised:
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Dodatno, neka pitanja se sama namiču.
03:26
How much clustering is there?
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Koliko tu skupina ima?
03:28
Is there more clustering than would be due to chance alone?
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Je li ih više nego što bi bilo za očekivati od slučajnosti?
03:31
How big are the clusters? How far do they reach?
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Koliko su veliki? Koliko daleko idu?
03:33
And, most importantly,
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I što je najvažnije
03:35
what causes the clusters?
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zbog čega nastaju skupine?
03:37
So we did some mathematics to study the size of these clusters.
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Matematičkim metodama smo analizirali veličinu skupina.
03:40
This here shows, on the Y-axis,
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Ovdje je na Y osi prikazana
03:42
the increase in the probability that a person is obese
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dodatna vjerojatnost da je osoba pretila
03:45
given that a social contact of theirs is obese
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u zavisnosti od toga koliko je pretil njihov društevni kontakt.
03:47
and, on the X-axis, the degrees of separation between the two people.
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Na X osi stupnjevi udaljenosti između osoba.
03:50
On the far left, you see the purple line.
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Skroz s lijeve strane vidite ljubičastu crtu
03:52
It says that, if your friends are obese,
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koja govori da ako su vaši prijatelji pretili
03:54
your risk of obesity is 45 percent higher.
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rizik da i vi budete pretili je 45% veći.
03:57
And the next bar over, the [red] line,
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A na sljedećem stupcu, narančasta crta
03:59
says if your friend's friends are obese,
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govori da ako su vam prijatelji od prijatelja pretili
04:01
your risk of obesity is 25 percent higher.
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vaš rizik pretilosti je 25% viši.
04:03
And then the next line over says
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I ona sljedeća crta govori
04:05
if your friend's friend's friend, someone you probably don't even know, is obese,
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da ako je prijatelj prijateljevog prijatelja, koga vjerojatno ne poznajete, pretil
04:08
your risk of obesity is 10 percent higher.
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vaš rizik da budete pretili je 10% viši.
04:11
And it's only when you get to your friend's friend's friend's friends
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I tek kad dođete do prijatelja prijatelja prijateljevog prijatelja
04:14
that there's no longer a relationship
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više ne postoji veza
04:16
between that person's body size and your own body size.
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između tjelesne težine te osobe i vaše.
04:20
Well, what might be causing this clustering?
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Znači, što uzrokuje ovo grupiranje?
04:23
There are at least three possibilities:
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Postoje minimalno tri mogućnosti.
04:25
One possibility is that, as I gain weight,
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Jedna je, kada se se ja debljam
04:27
it causes you to gain weight.
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utječem na tebe i debljaš se i ti,
04:29
A kind of induction, a kind of spread from person to person.
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neka vrsta širenja pretilosti sa osobe na osobu.
04:32
Another possibility, very obvious, is homophily,
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Druga mogućnost je, očigledno, homofilija.
04:34
or, birds of a feather flock together;
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Sličnosti se privlače.
04:36
here, I form my tie to you
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Ja stvaram vezu sa tobom
04:38
because you and I share a similar body size.
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jer imamo sličnu građu tijela.
04:41
And the last possibility is what is known as confounding,
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I zadnja mogućnost, nešto što ja zovem zbunjivanje,
04:43
because it confounds our ability to figure out what's going on.
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jer umanjuje vašu sposobnost, da vidite što se događa.
04:46
And here, the idea is not that my weight gain
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I ovdje nije stvar u tome, ako se ja debljam
04:48
is causing your weight gain,
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debljaš se i ti zbog toga,
04:50
nor that I preferentially form a tie with you
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niti da radije ulazim u vezu sa tobom
04:52
because you and I share the same body size,
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zato što imamo istu težinu
04:54
but rather that we share a common exposure
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već zato što smo oboje izloženi
04:56
to something, like a health club
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nečemu poput fitnes centra
04:59
that makes us both lose weight at the same time.
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zbog čega oboje mršavimo u isto vrijeme.
05:02
When we studied these data, we found evidence for all of these things,
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I kada smo analizirali podatke, pronašli smo dokaze za sve ove stvari
05:05
including for induction.
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uključujući i širenje.
05:07
And we found that if your friend becomes obese,
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I otkrili smo, da ako vaš prijatelj postaje pretil,
05:09
it increases your risk of obesity by about 57 percent
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to povećava se vaš rizik od pretilosti za 57%
05:12
in the same given time period.
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u istom razdoblju.
05:14
There can be many mechanisms for this effect:
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Iza ovog efekta stoje mnogi mehanizmi
05:17
One possibility is that your friends say to you something like --
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Jedan od mogućih je, da vam prijatelji kažu nešto poput --
05:19
you know, they adopt a behavior that spreads to you --
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usvajajući ponašanje koje se širi i na vas
05:22
like, they say, "Let's go have muffins and beer,"
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na primjer kažu "Hajmo na krafne i pivo"
05:25
which is a terrible combination. (Laughter)
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što je užasna kombinacija
05:28
But you adopt that combination,
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ali prihvatite li ju je,
05:30
and then you start gaining weight like them.
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počnete se debljati kao i oni.
05:33
Another more subtle possibility
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I još jedna, suptilnija mogućnost
05:35
is that they start gaining weight, and it changes your ideas
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je da ako se oni debljanju, vi mijenjate svoj doživljaj
05:38
of what an acceptable body size is.
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o tome što je prihvatljiva tjelesna težina.
05:40
Here, what's spreading from person to person
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I u ovom slučaju, stvar koja se prenosi sa osobe na osobu
05:42
is not a behavior, but rather a norm:
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nije ponašanje, već norma.
05:44
An idea is spreading.
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Širi se ideja.
05:46
Now, headline writers
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Sada, neki novinari
05:48
had a field day with our studies.
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su se pozabavili našim studijama.
05:50
I think the headline in The New York Times was,
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Naslov u New York Times-u je bio, mislim,
05:52
"Are you packing it on?
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"Debljate se?
05:54
Blame your fat friends." (Laughter)
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Krivi su vaši debeli prijatelji."
05:57
What was interesting to us is that the European headline writers
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Zanimljivo nam je bilo, da su europski novinari
05:59
had a different take: They said,
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drugačije pristupili stvari, oni bi rekli,
06:01
"Are your friends gaining weight? Perhaps you are to blame."
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"Debljaju li vam se prijatelji? Možda ste vi krivi?"
06:04
(Laughter)
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(Smijeh)
06:09
And we thought this was a very interesting comment on America,
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I učinilo nam se da je ovo zanimljiv komentar o samoj Americi,
06:12
and a kind of self-serving,
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uvijek samo svoj interes,
06:14
"not my responsibility" kind of phenomenon.
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fenomen tipa "nije moja odgovornost".
06:16
Now, I want to be very clear: We do not think our work
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Da budem jasan o jednoj stvari, naša saznanja
06:18
should or could justify prejudice
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ne smiju opravdavati predrasude
06:20
against people of one or another body size at all.
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prema ljudima ove ili one tjelesne veličine.
06:24
Our next questions was:
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Sljedeće što smo se pitali bilo je:
06:26
Could we actually visualize this spread?
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Možemo li vizualizirati ovo širenje?
06:29
Was weight gain in one person actually spreading
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Da li se debljanje jedne osobe prenosilo
06:31
to weight gain in another person?
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na drugu osobu?
06:33
And this was complicated because
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I ovaj dio bio je kompliciran
06:35
we needed to take into account the fact that the network structure,
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jer smo morali uzeti u obzir da se struktura mreže,
06:38
the architecture of the ties, was changing across time.
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način na koji je povezana, mijenja s vremenom.
06:41
In addition, because obesity is not a unicentric epidemic,
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I pošto pretilost nije epidemija s jednom polaznom točkom,
06:44
there's not a Patient Zero of the obesity epidemic --
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ne postoji "nulti pacijent" epidemije pretilosti.
06:47
if we find that guy, there was a spread of obesity out from him --
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Ne možemo za nijednu osobu reći da se pretilost širi od nje.
06:50
it's a multicentric epidemic.
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Imamo multicentrični problem.
06:52
Lots of people are doing things at the same time.
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Mnogi ljudi učestvuju u isto vrijeme.
06:54
And I'm about to show you a 30 second video animation
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I pokazati ću vam video animaciju od 30 sekundi
06:57
that took me and James five years of our lives to do.
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za koju nam je trebalo pet godina da je napravimo.
07:00
So, again, every dot is a person.
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Opet, svaka točka predstavlja jednu osobu.
07:02
Every tie between them is a relationship.
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Svaka poveznica između njih je međuljudski odnos.
07:04
We're going to put this into motion now,
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I sada ćemo pokrenuti animaciju
07:06
taking daily cuts through the network for about 30 years.
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promatrajući svakodnevno stanje mreže kroz oko 30 godina.
07:09
The dot sizes are going to grow,
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Točke će početi rasti.
07:11
you're going to see a sea of yellow take over.
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Vidjećete kako se pojavljuje mnoštvo žutih točaka.
07:14
You're going to see people be born and die --
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Vidjet će te ljude koji se rađaju i umiru.
07:16
dots will appear and disappear --
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Točke će se pojavljivati i nestajati.
07:18
ties will form and break, marriages and divorces,
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Veze će nastajati i kidati se. Brakovi i razvodi,
07:21
friendings and defriendings.
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sklapanje i raskidanje prijateljstava,
07:23
A lot of complexity, a lot is happening
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dosta složenosti, mnogo toga se događa
07:25
just in this 30-year period
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u samo trideset godina.
07:27
that includes the obesity epidemic.
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I to uključuje i epidemiju pretilosti.
07:29
And, by the end, you're going to see clusters
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I na kraju će te vidjeti skupine
07:31
of obese and non-obese individuals
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pretilih i ne-pretilih pojedinaca
07:33
within the network.
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unutar mreže.
07:35
Now, when looked at this,
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Nakon što sam ovo vidio
07:38
it changed the way I see things,
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promijenio sam način kako gledam na stvari
07:41
because this thing, this network
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jer ova stvar, ova mreža
07:43
that's changing across time,
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koja se mijenja s vremenom,
07:45
it has a memory, it moves,
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ima pamćenje, kreće se,
07:48
things flow within it,
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stvari plove kroz nju,
07:50
it has a kind of consistency --
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ima svoju vrstu konzistencije,
07:52
people can die, but it doesn't die;
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ljudi umiru, ali ona ne umire
07:54
it still persists --
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ona uvijek opstaje.
07:56
and it has a kind of resilience
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I ima neku vrstu otpornosti
07:58
that allows it to persist across time.
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koja joj dozvoljava da opstane s vremenom.
08:00
And so, I came to see these kinds of social networks
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Tako sam počeo promatrati dijelove društvenih mreža
08:03
as living things,
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kao živa bića,
08:05
as living things that we could put under a kind of microscope
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kao živa bića koja možemo staviti pod mikroskop
08:08
to study and analyze and understand.
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proučavati ih, analizirati i razumjeti.
08:11
And we used a variety of techniques to do this.
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I služimo se mnogim tehnikama da to učinimo.
08:13
And we started exploring all kinds of other phenomena.
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Počeli smo proučavati razne vrste fenomena.
08:16
We looked at smoking and drinking behavior,
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Promatrali smo pušenje i pijenje,
08:18
and voting behavior,
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glasanje na izborima,
08:20
and divorce -- which can spread --
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razvode, koji se mogu širiti,
08:22
and altruism.
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i altruizam.
08:24
And, eventually, we became interested in emotions.
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I na kraju su nas zainteresirale i emocije.
08:28
Now, when we have emotions,
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Sada, kada nas obuzmu emocije,
08:30
we show them.
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mi ih pokazujemo.
08:32
Why do we show our emotions?
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Zašto pokazujemo svoje emocije?
08:34
I mean, there would be an advantage to experiencing
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Znate, imalo bi prednosti da svoje emocije
08:36
our emotions inside, you know, anger or happiness.
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zadržimo u sebi, kao bijes ili sreću,
08:39
But we don't just experience them, we show them.
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ali mi ih ne zadržavamo, mi ih pokazujemo.
08:41
And not only do we show them, but others can read them.
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I ne samo da ih pokazujemo, već ih i drugi mogu tumačiti.
08:44
And, not only can they read them, but they copy them.
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I ne samo tumačiti već i kopirati.
08:46
There's emotional contagion
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Emocije se prenose
08:48
that takes place in human populations.
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u ljudskoj populaciji.
08:51
And so this function of emotions
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Tako da emocije imaju funkciju
08:53
suggests that, in addition to any other purpose they serve,
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pored svake ostale svrhe kojoj služe,
08:55
they're a kind of primitive form of communication.
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da su vrsta primitivnog oblika komunikacije.
08:58
And that, in fact, if we really want to understand human emotions,
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Ako želimo da stvarno razumijemo ljudske emocije,
09:01
we need to think about them in this way.
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moramo ih promatrati na ovaj način.
09:03
Now, we're accustomed to thinking about emotions in this way,
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Navikli smo da razmišljamo o svojim emocijama na sljedeći način,
09:06
in simple, sort of, brief periods of time.
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pojednostavljeno, u kratkim vremenskim rokovima.
09:09
So, for example,
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Tako na primjer
09:11
I was giving this talk recently in New York City,
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nedavno sam držao ovo predavanje u New Yorku
09:13
and I said, "You know when you're on the subway
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i rekao sam "Znate, kada ste na podzemnoj željeznici
09:15
and the other person across the subway car
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i osoba koja vam je prekoputa
09:17
smiles at you,
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vam se nasmije,
09:19
and you just instinctively smile back?"
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vi instinktivno odgovarate osmjehom."
09:21
And they looked at me and said, "We don't do that in New York City." (Laughter)
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Oni me pogledaju i kažu: "Mi to u New Yorku ne radimo".
09:24
And I said, "Everywhere else in the world,
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A ja kažem: "Svugdje drugo na svijetu
09:26
that's normal human behavior."
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to je normalno ljudsko ponašanje."
09:28
And so there's a very instinctive way
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Tako da postoji instinktivan način
09:30
in which we briefly transmit emotions to each other.
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kojim na brzinu prenosimo emocije jedni drugima.
09:33
And, in fact, emotional contagion can be broader still.
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Ustvari širenje emocija može biti još širih razmjera,
09:36
Like we could have punctuated expressions of anger,
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kao što postoje višestruki izljevi bijesa
09:39
as in riots.
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za vrijeme nereda.
09:41
The question that we wanted to ask was:
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Pitanje koje smo željeli postaviti
09:43
Could emotion spread,
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Mogu li se emocije širiti
09:45
in a more sustained way than riots, across time
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na održiviji način nego u neredima, tijekom dužeg vremena,
09:48
and involve large numbers of people,
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i uključiti veći broj ljudi,
09:50
not just this pair of individuals smiling at each other in the subway car?
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ne samo na pojedince koji se osmjehuju na podzemnoj željeznici?
09:53
Maybe there's a kind of below the surface, quiet riot
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Možda ispod površine postoji tihi nemir
09:56
that animates us all the time.
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koji nas pokreće svo vrijeme.
09:58
Maybe there are emotional stampedes
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Možda postoje emocionalna stampeda
10:00
that ripple through social networks.
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koja prolaze kroz društvene mreže.
10:02
Maybe, in fact, emotions have a collective existence,
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Možda emocije stvarno imaju kolektivno postojanje
10:05
not just an individual existence.
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ne samo pojedinačno.
10:07
And this is one of the first images we made to study this phenomenon.
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Ovo je jedna od prvih slika koju smo napravili da proučimo ovaj fenomen.
10:10
Again, a social network,
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Ponovno, društvena mreža,
10:12
but now we color the people yellow if they're happy
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no sada bojimo ljude u žuto, ako su sretni
10:15
and blue if they're sad and green in between.
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plavo ako su tužni i u zeleno ako su tu negdje između.
10:18
And if you look at this image, you can right away see
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I ako pogledate ovu sliku, odmah vidite,
10:20
clusters of happy and unhappy people,
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grupe sretnih i nesretnih ljudi.
10:22
again, spreading to three degrees of separation.
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ponovno se šireći preko tri stupnja udaljenosti.
10:24
And you might form the intuition
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Mogli bi formirati intuiciju
10:26
that the unhappy people
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kako se nesretni ljudi
10:28
occupy a different structural location within the network.
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nalaze na drugačijim strukturalnim pozicijama u mreži.
10:31
There's a middle and an edge to this network,
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Postoje sredina i rub ove mreže
10:33
and the unhappy people seem to be
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i nesretni ljudi se, izgleda
10:35
located at the edges.
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nalaze na rubovima.
10:37
So to invoke another metaphor,
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Da se poslužimo metaforom,
10:39
if you imagine social networks as a kind of
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ako zamislite društvenu mrežu kao
10:41
vast fabric of humanity --
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tkaninu načinjenu od ljudi
10:43
I'm connected to you and you to her, on out endlessly into the distance --
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- ja sam povezan sa tobom, ti s njom i tako u nedogled -
10:46
this fabric is actually like
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ta tkanina je ustvari kao
10:48
an old-fashioned American quilt,
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staromodni skrpani pokrivač,
10:50
and it has patches on it: happy and unhappy patches.
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puna zakrpa, sretnih i nesretnih zakrpa.
10:53
And whether you become happy or not
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I hoćete li biti sretni ili ne
10:55
depends in part on whether you occupy a happy patch.
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zavisi od toga da li ste u sretnoj ili nesretnoj zakrpi.
10:58
(Laughter)
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(Smijeh)
11:00
So, this work with emotions,
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Znači ovo funkcionira sa emocijama
11:03
which are so fundamental,
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koje su toliko temeljne,
11:05
then got us to thinking about: Maybe
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da smo pomislili da su možda
11:07
the fundamental causes of human social networks
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osnovni razlozi postojanja ljudskih društvenih mreža
11:09
are somehow encoded in our genes.
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na neki način kodirani u našim genima.
11:11
Because human social networks, whenever they are mapped,
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Jer ljudske društvene mreže, kada god da su istražene,
11:14
always kind of look like this:
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uvijek izgledaju otprilike ovako
11:16
the picture of the network.
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kao ova slika mreže,
11:18
But they never look like this.
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ali nikada ne izgledaju ovako.
11:20
Why do they not look like this?
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Zašto ne izgledaju ovako?
11:22
Why don't we form human social networks
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Zašto ne formiramo ljudske društvene mreže
11:24
that look like a regular lattice?
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koje izgledaju kao jednolična mreža.
11:26
Well, the striking patterns of human social networks,
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Naime, očigledna osobina ljudskih društvenih mreža
11:29
their ubiquity and their apparent purpose
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njihova sveprisutnost i očigledni smisao
11:32
beg questions about whether we evolved to have
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nameću pitanje da li smo evolurali
11:34
human social networks in the first place,
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da formiramo društvene mreže
11:36
and whether we evolved to form networks
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i da li smo evoluirali da imamo mreže
11:38
with a particular structure.
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određene strukture.
11:40
And notice first of all -- so, to understand this, though,
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I obratite prvo pažnju - da bi ovo razumjeli
11:42
we need to dissect network structure a little bit first --
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moramo prvo malo razložiti strukturu mreže.
11:45
and notice that every person in this network
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Obratite pažnju da svaka osoba u mreži
11:47
has exactly the same structural location as every other person.
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ima istu strukturnu poziciju kao i svaka druga osoba.
11:50
But that's not the case with real networks.
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Ali to nije slučaj sa pravim mrežama.
11:53
So, for example, here is a real network of college students
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Ovo je primjer stvarne mreže studenata s fakulteta
11:55
at an elite northeastern university.
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jednog od elitnih sveučilišta na sjeveroistoku.
11:58
And now I'm highlighting a few dots.
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I sada ću obilježiti par točaka.
12:00
If you look here at the dots,
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I ako pogledate ove točke ovdje
12:02
compare node B in the upper left
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uporedite čvor B na gornjoj lijevoj strani
12:04
to node D in the far right;
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s čvorom D na donjoj desnoj.
12:06
B has four friends coming out from him
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B je povezan s četiri prijatelja.
12:08
and D has six friends coming out from him.
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D je povezan sa šest prijatelja.
12:11
And so, those two individuals have different numbers of friends.
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Tako da ove dvije osobe imaju različit broj prijatelja --
12:14
That's very obvious, we all know that.
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ovo je očigledno, to svi znamo.
12:16
But certain other aspects
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Ali neki drugi aspekti
12:18
of social network structure are not so obvious.
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struktura društvene mreže nisu tako očiti.
12:20
Compare node B in the upper left to node A in the lower left.
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Uporedite B gore lijevo, sa čvorom A dolje lijevo.
12:23
Now, those people both have four friends,
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Obadvoje imaju po četiri prijatelja
12:26
but A's friends all know each other,
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Ali prijatelji od A se međusobno poznaju,
12:28
and B's friends do not.
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a prijatelji od B ne.
12:30
So the friend of a friend of A's
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Znači prijatelj prijatelja osobe A
12:32
is, back again, a friend of A's,
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je opet prijatelj sa A.
12:34
whereas the friend of a friend of B's is not a friend of B's,
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Dok prijatelj prijatelja od B, nije prijatelj sa B.
12:36
but is farther away in the network.
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i udaljeniji je u mreži.
12:38
This is known as transitivity in networks.
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Ovo nazivamo tranzitivnošću u mrežama.
12:41
And, finally, compare nodes C and D:
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I na kraju usporedite čvorove C i D.
12:43
C and D both have six friends.
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C i D oboje imaju po šest prijatelja.
12:46
If you talk to them, and you said, "What is your social life like?"
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I kada bi ih pitali "Kakav vam je društveni život?"
12:49
they would say, "I've got six friends.
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rekli bi "imam šest prijatelja
12:51
That's my social experience."
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to je moj društveno okruženje."
12:53
But now we, with a bird's eye view looking at this network,
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Ali sada, promatrajući ovu mrežu iz ptičije presprektive
12:56
can see that they occupy very different social worlds.
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vidimo da se nalaze u skroz drugačijim društvenim svjetovima,
12:59
And I can cultivate that intuition in you by just asking you:
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i mogu li vam pobuditi osjećaj za to ako vas pitam
13:01
Who would you rather be
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tko bi radije bili
13:03
if a deadly germ was spreading through the network?
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ako se mrežom širi smrtonosni virus?
13:05
Would you rather be C or D?
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Da li bi radije bili C ili D?
13:08
You'd rather be D, on the edge of the network.
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Da li bi radije D, na rubu mreže.
13:10
And now who would you rather be
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A tko bi radije bili
13:12
if a juicy piece of gossip -- not about you --
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ako se mrežom širi sočan trač,
13:15
was spreading through the network? (Laughter)
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ne o vama.
13:17
Now, you would rather be C.
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Radije bi bili C.
13:19
So different structural locations
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Tako da drugačije lokacije u strukturi
13:21
have different implications for your life.
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imaju različite posljedice na vaš život.
13:23
And, in fact, when we did some experiments looking at this,
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I kada smo u nekim eksperimentima promatrali ovo
13:26
what we found is that 46 percent of the variation
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našli smo da se 46% varijacije
13:29
in how many friends you have
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u broju prijatelja koje imate
13:31
is explained by your genes.
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objašnjanava vašim genima.
13:33
And this is not surprising. We know that some people are born shy
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I ovo nije iznenađujuće. Znamo da se neki ljudi rode stidljivi
13:36
and some are born gregarious. That's obvious.
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a neki društveni. To je očigledno.
13:39
But we also found some non-obvious things.
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Ali našli smo i neke stvari koje su manje očigledne.
13:41
For instance, 47 percent in the variation
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Na primjer, 47% varijacije
13:44
in whether your friends know each other
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da li se vaši prijatelji međusobno poznaju
13:46
is attributable to your genes.
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se može povezati sa vašim genima.
13:48
Whether your friends know each other
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Da li se vaši prijatelji međusobno poznaju
13:50
has not just to do with their genes, but with yours.
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nema samo veze sa njihovim genima, već i vašim.
13:53
And we think the reason for this is that some people
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I razlog ovome je kako vjerujemo, da neki ljudi
13:55
like to introduce their friends to each other -- you know who you are --
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rado upoznaju svoje prijatelje jedne sa drugima
13:58
and others of you keep them apart and don't introduce your friends to each other.
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a neki opet ih drže razdvojenima i ne upoznaju svoje prijatelje.
14:01
And so some people knit together the networks around them,
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Dok neki ljudi pletu mreže oko sebe
14:04
creating a kind of dense web of ties
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stvarajući neku vrstu dobro povezane mreže
14:06
in which they're comfortably embedded.
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u kojoj su ugodno ukorijenjeni.
14:08
And finally, we even found that
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I na kraju smo čak pronašli
14:10
30 percent of the variation
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da 30% varijacije
14:12
in whether or not people are in the middle or on the edge of the network
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da li se ljudi nalaze u sredini ili krajevima mreže
14:15
can also be attributed to their genes.
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također može biti određeno genima.
14:17
So whether you find yourself in the middle or on the edge
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Da li se nalazite u sredini ili na rubu
14:19
is also partially heritable.
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je znači dijelom nasljedno.
14:22
Now, what is the point of this?
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Sada, koji ja smisao ovoga?
14:25
How does this help us understand?
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Na koji način nam pomaže da razumijemo?
14:27
How does this help us
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Kako nam ovo pomaže
14:29
figure out some of the problems that are affecting us these days?
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da razumijemo probleme sadašnjice?
14:33
Well, the argument I'd like to make is that networks have value.
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Stav koji bih ja zauzeo, je da mreže imaju vrijednost.
14:36
They are a kind of social capital.
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One su neka vrste društvenog kapitala.
14:39
New properties emerge
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Nastaju nove osobine
14:41
because of our embeddedness in social networks,
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iz ukorijenjenosti u društvenu mrežu.
14:43
and these properties inhere
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I ove osobine su svojstvene
14:46
in the structure of the networks,
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strukturi mreže
14:48
not just in the individuals within them.
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a ne pojedincima koje su u njima.
14:50
So think about these two common objects.
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Razmislite o ova dva obična predmeta.
14:52
They're both made of carbon,
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Obadva se sastoje od ugljika
14:54
and yet one of them has carbon atoms in it
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ali su u jednom od njih atomi ugljika
14:57
that are arranged in one particular way -- on the left --
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raspoređeni na određeni način, ovdje lijevo,
15:00
and you get graphite, which is soft and dark.
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i dobijemo grafit, koji je mekan i taman.
15:03
But if you take the same carbon atoms
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No uzmeno li iste atome ugljika
15:05
and interconnect them a different way,
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i povežemo ih na drugi način
15:07
you get diamond, which is clear and hard.
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dobijemo dijamant, koji je proziran i tvrd.
15:10
And those properties of softness and hardness and darkness and clearness
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I ove osobine, kao mekoća, tvrdoća, zatamnjenost ili prozirnost
15:13
do not reside in the carbon atoms;
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se ne nalaze u atomima ugljika,
15:15
they reside in the interconnections between the carbon atoms,
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negu u vezama između atoma ugljika
15:18
or at least arise because of the
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ili se u najmanju ruku pojavljuju zbog
15:20
interconnections between the carbon atoms.
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vrste veze između atoma ugljika.
15:22
So, similarly, the pattern of connections among people
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Slično tomu, obrazac veza između ljudi
15:25
confers upon the groups of people
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donosi grupi ljudi
15:28
different properties.
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različite osobine.
15:30
It is the ties between people
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Veze između ljudi
15:32
that makes the whole greater than the sum of its parts.
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su ono zbog čega je cjelina veća od zbroja njenih dijelova.
15:35
And so it is not just what's happening to these people --
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I nije samo ono što se dešava ljudima
15:38
whether they're losing weight or gaining weight, or becoming rich or becoming poor,
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je li mršave ili se debljaju, da li se bogate ili osiromašuju
15:41
or becoming happy or not becoming happy -- that affects us;
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ili postaju stretni ili nesretni, to što utiče na nas.
15:44
it's also the actual architecture
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To je također i arhitektura
15:46
of the ties around us.
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veza oko nas.
15:48
Our experience of the world
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Naše poimanje svijeta
15:50
depends on the actual structure
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zavisi od strukture
15:52
of the networks in which we're residing
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mreže u kojoj se nalazimo
15:54
and on all the kinds of things that ripple and flow
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i o svim stvarima koje se prožimaju i teku
15:57
through the network.
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kroz mrežu.
16:00
Now, the reason, I think, that this is the case
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Sada, mislim da je razlog ovomu
16:03
is that human beings assemble themselves
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je da se ljudska bića povezuju
16:05
and form a kind of superorganism.
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i formiraju neku vrstu superorganizma.
16:09
Now, a superorganism is a collection of individuals
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Superorganizam je neka skupina pojedinaca
16:12
which show or evince behaviors or phenomena
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koji pokazuje ili iz kojeg se vide ponašanja ili fenomeni
16:15
that are not reducible to the study of individuals
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koje se ne mogu svesti na proučavanje pojedinca
16:18
and that must be understood by reference to,
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i moraju se razumjeti u odnosu na
16:20
and by studying, the collective.
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i kroz analizu kolektiva
16:22
Like, for example, a hive of bees
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kao na primjer roj pčela
16:25
that's finding a new nesting site,
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koje traži mjesto za novu košnicu.
16:28
or a flock of birds that's evading a predator,
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ili jato ptica koje bježi od grabljivca
16:30
or a flock of birds that's able to pool its wisdom
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ili jato ptica koje je u stanju čuvati svoje iskustvo
16:33
and navigate and find a tiny speck
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i navigirati da nađu maleni
16:35
of an island in the middle of the Pacific,
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otok negdje nasred Pacifika.
16:37
or a pack of wolves that's able
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Ili čopor vukova koji može
16:39
to bring down larger prey.
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uloviti veliku lovinu.
16:42
Superorganisms have properties
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Superorganizmi imaju osobine
16:44
that cannot be understood just by studying the individuals.
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koje se ne mogu razumjeti ako samo promatramo pojedince.
16:47
I think understanding social networks
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Smatram da nam razumjevanje društvenih mreža,
16:49
and how they form and operate
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kako se formiraju i funkcioniraju
16:51
can help us understand not just health and emotions
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može pomoći da razumijemo, ne samo zdravlje i emocije
16:54
but all kinds of other phenomena --
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već sve vrste fenomena
16:56
like crime, and warfare,
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poput kriminala ili ratovanja
16:58
and economic phenomena like bank runs
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i ekonomskih fenomena poput paničnog dizanja ušteđevine
17:00
and market crashes
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i krahova tržišta,
17:02
and the adoption of innovation
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prihvatanja inovacije
17:04
and the spread of product adoption.
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i uvođenje novog proizvoda.
17:06
Now, look at this.
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Vidite sada ovo.
17:09
I think we form social networks
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Mislim da formiramo društvene mreže
17:11
because the benefits of a connected life
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jer prednosti povezanog života
17:13
outweigh the costs.
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nadmašuju troškove.
17:16
If I was always violent towards you
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Ako sam ja bio nasilan prema vama
17:18
or gave you misinformation
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ili vam dao pogrešnu informaciju
17:20
or made you sad or infected you with deadly germs,
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ili vas rastužio, ili vas zarazio smrtonosnim virusom,
17:23
you would cut the ties to me,
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raskinuli bi vezu sa mnom
17:25
and the network would disintegrate.
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i mreža bi se raspadala.
17:27
So the spread of good and valuable things
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Tako da je širenje dobrih i vrijednih stvari
17:30
is required to sustain and nourish social networks.
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potrebno za održavanje i hranjenje društvenih mreža.
17:34
Similarly, social networks are required
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Slično, društvene mreže su neophodne
17:36
for the spread of good and valuable things,
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za širenje dobrih i vrijednih stvari.
17:39
like love and kindness
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poput ljubavi i dobrote
17:41
and happiness and altruism
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sreće i altruizma
17:43
and ideas.
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i ideja.
17:45
I think, in fact, that if we realized
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Ustvari mislim da ako bi shvatili
17:47
how valuable social networks are,
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koliko društvene mreže vrijede
17:49
we'd spend a lot more time nourishing them and sustaining them,
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više bi vremena provodili njegujući i održavajući ih.
17:52
because I think social networks
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jer smatram da su socijalne mreže
17:54
are fundamentally related to goodness.
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u osnovi povezane sa dobrotom
17:57
And what I think the world needs now
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i ono što svijetu trenutno treba
17:59
is more connections.
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je više veza.
18:01
Thank you.
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Hvala.
18:03
(Applause)
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(Pljesak)
ABOUT THE SPEAKER
Nicholas Christakis - Physician, social scientistNicholas Christakis explores how the large-scale, face-to-face social networks in which we are embedded affect our lives, and what we can do to take advantage of this fact.
Why you should listen
People aren't merely social animals in the usual sense, for we don't just live in groups. We live in networks -- and we have done so ever since we emerged from the African savannah. Via intricately branching paths tracing out cascading family connections, friendship ties, and work relationships, we are interconnected to hundreds or even thousands of specific people, most of whom we do not know. We affect them and they affect us.
Nicholas Christakis' work examines the biological, psychological, sociological, and mathematical rules that govern how we form these social networks, and the rules that govern how they shape our lives. His work shows how phenomena as diverse as obesity, smoking, emotions, ideas, germs, and altruism can spread through our social ties, and how genes can partially underlie our creation of social ties to begin with. His work also sheds light on how we might take advantage of an understanding of social networks to make the world a better place.
At Yale, Christakis is a Professor of Social and Natural Science, and he directs a diverse research group in the field of biosocial science, primarily investigating social networks. His popular undergraduate course "Health of the Public" is available as a podcast. His book, Connected, co-authored with James H. Fowler, appeared in 2009, and has been translated into 20 languages. In 2009, he was named by Time magazine to its annual list of the 100 most influential people in the world, and also, in 2009 and 2010, by Foreign Policy magazine to its list of 100 top global thinkers
Nicholas Christakis | Speaker | TED.com