New Mobility

GLOBAL INVESTOR 2.13 — 50
Giselle Weiss: Your early research is associated
with the wildly popular idea of six
degrees of separation, which far predates
you. How did that idea spread?
Duncan Watts: I don’t know. But the
notion that we are all connected through
a short chain of acquaintances has been
around for a long time. It shows up in
a 1929 short story called “Chains” by the
Hungarian poet Frigyes Karinthy. And
the urbanist Jane Jacobs speculated about
it in her famous book, “The Death and
Life of Great American Cities.”
They didn’t call it six degrees
of separation, though.
Duncan Watts: No. That label comes
from the title of a Broadway play of the
1990s by John Guare. The actual history is
a little involved. But in any event, in 1967
psychologist Stanley Milgram set out to test
the idea by having people in Boston deliver
letters to people (“targets”) in Omaha,
Nebraska, through the intermediary of
others known only on a first-name basis.
He found that the average length of the
letter chains that reached the targets was
six. He called it the small world problem.
DISPERSION
How ideas
spread
Every human advance, and what we call culture, relies on the
human capacity to embrace new ideas en masse. But how does that
happen? How does an idea become so compelling that it is worth
sharing? More important, how is it that ideas come to be adopted?
Duncan Watts has made a career of studying how ideas spread.
INTERVIEW by Giselle Weiss
“Some things
do spread quite
a lot … but they
are very rare,
one in a million
events.”
Where did your research come in?
Duncan Watts: In the 1990s, I was
studying synchronization among crickets –
who chirps with whom. Then one day
on the phone, my dad asked me whether
I’d ever heard of the idea that everyone
is only six handshakes away from the
president of the United States. It occurred
to me that both problems involved networks,
and that interested me.
What makes the idea so powerful?
Duncan Watts: We’re attracted to
the Enlightenment idea of ourselves as
independent individuals who decide
what we want to do and go out and do it.
But the reality is that we’re very much
enmeshed in social relations. Everything
we do and care about involves other
people. These are network concepts.
Recently, you’ve been working on the
structure of viral diffusion, for example,
of tweets on Twitter. What’s that about ?
Duncan Watts: We’ve been mapping
the spread of information, particularly
online. When you think about how information
spreads, it’s natural to liken it
to the spread of a disease. In fact, people
have been doing that for a long time
in marketing. And it’s been popularized
in recent years by people like Malcolm
Gladwell, author of “The Tipping Point,”
who very explicitly draws the analogy
between the spread of behaviors or beliefs
and diseases.
That sounds reasonable.
Duncan Watts: At a certain level,
it is. But it’s tempting to go a step further
and apply the same mathematical models
that have been developed to understand
the spread of a disease to the spread
of ideas or products.
What’s wrong with that?
Duncan Watts: There are all sorts
of models of how things spread, and they’re
often incompatible with each other. Moreover,
we have very little data to test any
of these models. For example, if you want
to trace the spread of an idea, you have
to be able to observe that person A has that
idea, and then that person tells B, and then
person B has the idea, and now person B
tells person C. Mapping this out in a population
of millions of people with hundreds of
thousands and millions of things to observe
is a tremendously difficult process.
So how do you approach it ?
Duncan Watts: We’ve done a lot of work
using Twitter data – news, media, images –