
Small Worlds, Kevin Bacon & The Adjacent Possible | Nancy Hillis, MD & Bruce Sawhill, PhD
Small Worlds, Kevin Bacon & The Adjacent Creative
As anyone who has followed our blogs (and books) knows, the concept of adjacency and the adjacent possible as a key component of creativity comes up very often.
Today we will approach the inverse of that concept, that of the distant connection. And how it is possible to make the distant close and what remarkable things happen when we do that.
Six Degrees Of Separation
The concept of “six degrees of separation” has entered the vernacular, people talk about it at cocktail parties. And, like several of the other favorites of cocktail parties (politics, technology, entertainment, and gossip) often without nuanced understanding.
The earliest known attribution of the phrase is by the playwright John Guare who published a play in 1990 which was made into a movie in 1993 called Six Degrees of Separation. (with Will Smith and others)
A character states:
I read somewhere that everybody on this planet is separated by only six other people. Six degrees of separation between us and everyone else on this planet. The President of the United States, a gondolier in Venice, just fill in the names. I find it A) extremely comforting that we’re so close, and B) like Chinese water torture that we’re so close because you have to find the right six people to make the right connection… I am bound to everyone on this planet by a trail of six people.
Character in Six Degrees Of Separation
Guglielmo Marconi
Guare attributed this concept to Guglielmo Marconi (1874-1937), the Italian inventor of radio and the co-recipient of the 1909 Nobel Prize in Physics.

Gublielmo Marconi, Nobel Prize physicist and radio inventor
Opera, Venice & The Hotel Marconi
A personal note: When Nancy and I were on a San Francisco Opera Guild tour of operatic Italy with our daughter Kimy (who was an opera student at the time) we spent several days in Venice.
While enjoying a lunch on the banks of the Grand Canal, we looked across to the other side and saw a small hotel, sandwiched in-between a number of others of similar scale, called the ‘Hotel Marconi’.
In small lettering underneath the hotel’s name were the words “Wi-Fi.”
Of course a hotel named after the inventor of radio telegraphy would have to have WiFi! Finding such geeky humor is a source of much nerdy pleasure.
But it’s not just happenstance that Marconi may have said this. The inspiration to think about it came from the creation of electronic communication and the feeling that it was shrinking the world enormously.

Social network example
Small World Networks
The concept of six (or any other small number) degrees of separation became formalized by a chain-letter sending experiment put together by the psychologist Stanley Milgram at Harvard University in 1967.
A start person and an end person were chosen (geographically far apart, but all in the United States) If the start person knew the end person by chance, then the experiment was over for that particular pair and the degree of separation was one.
If not, the start person was told to send the letter to someone they know who they thought was more likely to know the end person.
The letters followed a pattern—usually a long jump to get in the proximity of the person, then a bunch of short ones to hone in on them, averaging about six.

Small world network example with short and long links. Same network on right, highlighting short/long links.
Kevin Bacon Number
These “small world networks” entered the popular lexicon with the idea of the “Kevin Bacon number.”
The actor claimed he had worked with everyone in Hollywood around 1994, and it became a parlor game (even for those without parlors) to find the shortest link between Kevin and any other actor or actress.

Kevin Bacon, actor
The result is not particular to Kevin Bacon.
One could pick any one of hundreds of Hollywood characters and come up with a similar number. It is a network without a well-defined center. Everybody and nobody is in the center!
It’s like a map drawn on the surface of a balloon.

Partial Kevin Bacon graph By Userr999 – https://commons.wikimedia.org/w/index.php?curid=124350933
Santa Fe Institute
Milgram’s experiment was repeated by a former colleague of Bruce’s at the Santa Fe Institute, Duncan Watts, who moved the letter-writing technology into the email age in 2001 and was thus able to get a much larger set of data.
Watts also collaborated with Stephen Strogatz to move beyond identifying and mapping small world networks and to think about mechanisms for creating and growing them dynamically.
Because naturally one wants to know how they might come into being. Some of the algorithms to build them are very simple, like a “rich get richer” idea—someone with a lot of connections is predisposed to snag newcomers into the network more than their poorer cousins.
This builds a particular flavor of small-world network called a “power-law network.”
How To Make Your Own Small World Networks
Insight comes from understanding how to make your own small-world networks “in the lab.” (or the computer or on a piece of paper)
- Imagine a city on a grid, like Manhattan.
- Assume you know everyone in your block through a connection or two.
- Now have each person in a block pull another block address out of their hat, anywhere in the world.

Manhattan grid
Adjacent & Far-Flung
You end up with a network that is both adjacent and far-flung. Getting to southern Madagascar from suburban Seattle has one or two long jumps and the rest are neighborly.
Nearby connections have the virtue of being predictable. The person in apartment 101 is likely to know the one in 102, who is likely to know the one in 103, for instance.
The long jumps are much less predictable. Getting to southern Madagascar from the Seattle area might take any number of different paths.
There is a sweet spot in this dynamic between local/predictable and distant/unpredictable that gives the advantages of both-wide coverage and the familiarity of local connection. This is the power of the small-world network.
Networks & Structures
Research over the last quarter century has found these networks to be nearly ubiquitous. Everything from brain architecture to the structure of language to genetic networks.
It’s tempting to go from “many things” to “everything,” or as the science fiction writer Arthur C. Clarke opined,
Give me a teaspoon of fact at breakfast and I’ll have you a ton of theory by teatime.
-Arthur C. Clarke
Or the popular warning, “To a hammer, everything is a nail.”
So with that in mind, here’s a hypothesis about creativity, artistic and otherwise.

Hammer with nailing attempts
Hypothesis About Creativity
The hypothesis: Is the structure of creativity a small-world network, composed of small steps (the adjacent possible) and occasional huge leaps (radical jumps in expression), the combination of which covers a huge landscape?
And, if that weren’t enough, how would one rigorously test this hypothesis?
Context Switching: Adding A Wrinkle Or Two
Then there is the relatively unexplored aspect of context switching.
Extending the idea of small world networks to mapping concepts and their evolution is a kind of adjacent possible play, it starts with something well understood and adds a wrinkle or two.
The Adjacent Possible & Revolutions
But it brings up the possibility that:
The adjacent possible in one context could precipitate a revolution in another.
In engineering, figuring out how to make a steam engine portable (adjacent possible of the stationary steam engine) generated a revolution in transportation.

Early Steam Train
Art, Science & Revolutions
Creativity may do in time what small world networks do in space, either geographical or in the abstract space of connections.
Art and science and sometimes engineering make incremental “neighborly” changes, punctuated by revolutions, from Cubism to quantum mechanics to building things out of steel.
In terms of applying small-world network ideas, concepts are different than the original subject of people: They come and go, they mutate, they change their character and identity *as a result* of interacting with other ones.
But the science of small world networks may be a fertile place to develop new theories of creativity.
And perhaps to understand if creativity is uniquely human.
From our studio to yours,
Nancy & Bruce
P.S. Want to go deeper? Get The Art Of The Possible Series.

QR Code- The Art Of The Possible Series
P.S.S. Leave your thoughts and comments below. We can’t wait to hear what you have to say.
I made the acquaintance of a Palestinian gentleman in the early 70’s who shared his story and concept of being only 3-degrees separated from anyone in the world he wanted to talk to.