Name: 【TED】Nicholas Christakis: The hidden influence of social networks (Nicholas Christakis: The hidden influence of social networks)
Uploaded: 2017-12-02T18:35:01.000Z
Duration: 18 min 45 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

For me, this story begins about 15 years ago,

when I was a hospice doctor at the University of Chicago.

And I was taking care of people who were dying and their families

And I was observing what happened to people and their families

over the course of their terminal illness.

And in my lab, I was studying the widower effect,

which is a very old idea in the social sciences,

So, when I die, my wife's risk of death can double,

And I had gone to take care of one particular patient,

And the daughter was exhausted from caring for her mother.

and I get a phone call from the husband's friend,

So here I get this call from this random guy

And so I suddenly realized two very simple things:

was not restricted to husbands and wives.

And second, it was not restricted to pairs of people.

like pairs of people connected to each other.

And then I realized that these individuals

would be connected into foursomes with other pairs of people nearby.

were embedded in other sorts of relationships:

And that, in fact, these connections were vast

broad set of connections with each other.

So I started to see the world in a completely new way

that we're embedded in these social networks,

So, social networks are these intricate things of beauty,

that one has to ask what purpose they serve.

I mean, how do they form? How do they operate?

And, along with my collaborator, James Fowler,

we began to wonder whether obesity really was epidemic

and could it spread from person to person

like the four people I discussed earlier.

So this is a slide of some of our initial results.

Every dot is a person. We make the dot size

if your BMI, your body mass index, is above 30 --

So, if you look at this image, right away you might be able to see

But the visual complexity is still very high.

It's not obvious exactly what's going on.

In addition, some questions are immediately raised:

Is there more clustering than would be due to chance alone?

How big are the clusters? How far do they reach?

So we did some mathematics to study the size of these clusters.

the increase in the probability that a person is obese

given that a social contact of theirs is obese

and, on the X-axis, the degrees of separation between the two people.

On the far left, you see the purple line.

your risk of obesity is 45 percent higher.

your risk of obesity is 25 percent higher.

if your friend's friend's friend, someone you probably don't even know, is obese,

your risk of obesity is 10 percent higher.

And it's only when you get to your friend's friend's friend's friends

Subtitles ListPlay Video

【TED】Nicholas Christakis: The hidden influence of social networks (Nicholas Christakis: The hidden influence of social networks)

obvious

phenomenon

vast

obesity