Six Degrees of Separation

Through just five or six intermediaries, you could bethe network was neither entirely regular nor utterly
linked to millions of others. It is the notion behind whatrandom. They expected the number of handshakes
has been dubbed the small world effect.It has happedneeded to link people to drop as the random links
to most of us, and it's virtually guaranteed to happen atgrew.But what they discovered was startling: just a
again - especially if you attend a social gathering.tiny number of random links was enough to
Whenever you have people eager to talk with one"short-circuit" an otherwise huge, regular network,
another, the chances are that some will find that theyallowing apparently unrelated friends to be linked in just
have friends and acquaintances in common. It is, asa few handshakes.The computer revealed how easy
they say, a small world.It may be a common enoughit is to turn even a vast network into a small world: if
experience, but the so-called small world effect isonly one in 100 people have a random link to anyone
turning out to have some pretty big consequences. Inelse in the network, the average number of
the last 18 months it has become one of the hottesthandshakes drops ten-fold.THEY ARE
subjects in science. Now some believe it couldEVERYWHEREBut computer simulations are one
revolutionize the way we think about everything fromthing; can small worlds be created so easily in the real
economic crashes to globalization.The story of how anone? Watts and Strogatz set about searching for a
apparently trivial social phenomenon turned out to havehuge real-life network that they could probe for signs
far from trivial implications has its origins in a bizarreof the small world effect. They found the perfect, if
experiment carried out over 30 years ago byunlikely, example in the Internet Movie Database, a
psychologist Stanley Milgram.Milgram was trying tocomputer searchable catalogue with the names of
uncover the connections that lurk in our networks ofover 200,000 actors and the films they have appeared
friends and acquaintances, and hit upon a novel wayin.Analyzing the database, Watts and Strogatz found
of revealing them. He recruited people in various USthat the typical actor has worked with around 60
states and sent each of them a package, togetherothers. If the showbiz network were completely
with some instructions.These revealed that theregular, with no random short-circuits, that figure would
packages were actually intended to two people pickedimply that you'd typically have to go through 1,800 other
by Milgram, who gave their names and some vagueactors and their films to link one actor to another. Yet
clues about where they lived, their occupation and age.the computer showed that it is possible to link any
What he did not give, however, was a precise postalactor to any other via just three intermediaries. The
address. The participants were then told to send thevast movie business is really a small world.In fact, this
packages to whichever of their acquaintances theyhad been known for years by movie buffs who play
judged most likely to know the targets personally andthe so-called Kevin Bacon Game. The aim of the
be able to make the final delivery.Keeping track of thegame is to link the eponymous American actor to any
postings, Milgram made the stunning discovery that theother via the fewest number of intermediaries.Players
packages typically reached the two target peoplewere often struck by how often they could answer
after passing through the hands of just five otherwith the names of very few actors. For example,
people. Later experiments produced similar results,Bacon can be linked to Charlie Chaplin in just three
making the conclusion inevitable. It seems that, onsteps: Bacon played in a film with Laurence Fishburn,
average, everyone in America from arms dealer towho in turn was in a film with Marlon Brando, who
zoo keeper can be connected to everyone else via ahimself once appeared with Chaplin.Watts and
chain of just five or six intermediaries.It is a result thatStrogatz had confirmed what many players suspected
becomes more bizarre the more you think about it.was the explanation: the "short-circuiting" effect of a
Sociologists estimate that we each typically havehandful of actors whose careers span different eras,
around 300 or so acquaintances - people we're ongenres and cultures. For example, by starring in both
first-name terms with. That suggests we're just oneLethal Weapon and Hamlet, Mel Gibson short-circuits
hand-shake (or email) away from 300 people, twothe all-action and classical genres, while martial arts
away from 90,000, three away from 27 million and soactor Bruce Lee links the Chinese film industry to
on.Viewed this way, the real surprise about Milgram'sHollywood.The world of showbiz is now recognized as
research is that it takes as many as five or sixa classical small world. That is, it is made up of lots of
handshakes to connect every American to everylittle cliques of actors, most of whom stay in their own
other. An average of just four should suffice topatch of the industry, mixed in with a few highly
connect up to 250 millions inhabitants of the US.Butversatile ones with random links right across the acting
there is a big assumption in this quick calculation: thatnetwork who thus link every actor to every other via
our 300 friends are randomly spread throughout thevery few steps.When Watts and Strogatz published
population so that every American is likely to know,their findings in the leading science journal Nature, it
say, Alan Greenspan as Al at the corner store. But thetriggered an explosion of media coverage. But it also
fact is that our friends tend to fall into cliques: peoplesparked interest among academics in a diverse range
who have similar levels of education, interests andof fields, all wondering whether small world effects are
opinions.This, however, just makes Milgram's findingsat work in their own patches.The corporate world
even more baffling: for if all our friends were confineddoes show signs of being under the influence of small
to such rigid cliques, we would hardly ever discoverworld effects, according to Bruce Kogut of the
we have friends in common. Each American, forWharton School of Business at the University of
example, would then be separated by an average ofPennsylvania, and Gordon Walker at the Cox School
almost one million handshakes...250 million divided byof Business at the Southern Methodist University in
300 from each other. By that reckoning, Milgram shouldTexas.Kogut and Walker applied Watts and Strogatz's
have died long before any of his packages reachedmethods to the ownership networks spanning over
their targets.There is clearly something odd going on500 of Germany's biggest corporations. Predictably,
here. Our networks of friends are not randomlythey found lots of cliques in the ownership of firms, the
spread across society. Yet they still allow us to beresult of various tie-ups and mergers. But they also
linked to each other via few intermediaries, so that wefound that the short-circuiting effect of a few
often end up discovering "It's a small world". How docorporations typically allowed the ownership of any
they do it?It was this that intrigued Duncan Watts, inone firm to be linked to any other via just four
1996 still a graduate at Cornell University. Watts hadintermediaries. In other words, for all their diversity,
been working on a nice, solid doctorate about theGermany's biggest firms actually form a cosy small
chirps of lovelorn crickets. But he had run into aworld.This explains why firms with apparently tenuous
problem: how do the crickets fall into step so quickly?links to one another can still show similar corporate
Was each listening to all his fellow crickets, or just tobehavior. But it may also have implications for the way
his closest neighbors?Then Watts remembered athese companies deal with globalization.Small world
funny bit of folklore that his father had told him: thattheory shows it only takes a few random links to
every American is just a few handshakes away fromshort-circuit a vast network. So it's likely that the whole
knowing the president of the United States. Wattscorporate world has already become a small
wondered if there was a connection between thisworld.The study of small worlds is still in its infancy, yet
apparent bit of folklore and the problem he was tryingit is already clear that their presence holds both
to solve and perhaps many others too.Wattsbenefits and threats. Economists and business studies
expected his idea would be ridiculed by his advisor,experts are likely to reveal many more examples of
Steve Strogatz at Cornell's department of theoreticalsmall worlds and their implications in the years
and applied mechanics. Instead, Stogatz also fell underahead.Selling on eBay and the Internet is still a relatively
the spell of the big mystery of the small world effect,a new phenomenon with unprecedented opportunity.
and the two joined forces to try and solve it.TheyAdam Ginsberg, recently featured on NBC's Today
began by using a computer to create lots of networksShow is an author and educator and has built a small
of virtual "friends", and measuring how manyfortune selling on eBay. As an early Internet pioneer,
"handshakes" were needed to connect one friend toAdam discovered a system for generating wealth -
another in a totally different part of the network.At onethrough the power of the eBay marketplace.Adam
extreme were the utterly regular networks, wherepersonally sold over $20,000,000 on eBay and the
every friend only knows those right next to them.Internet in the last three years. Currently he travels the
Devoid of any long range connections capable ofworld sharing his knowledge, expertise and experience
linking, say, Bill Clinton to some store-keep in Hawaii,with others. Adam's book, "How to Buy, Sell & Profit
these networks typically demanded lots ofon eBay", went to #1 on Amazon within 3 days of
handshakes before one person could be connected tobeing released. Learn how Adam has solved the
another. Right at the other extreme were totallymystery of success on eBay and how you can apply
random networks, where people were just as likely tohis system to capitalize on this hot new money making
have personal friends in the White House as inopportunity. Adam has also created several best
Hawaiian stores.Watts and Strogatz were intrigued byselling e-books and software to enable you to
what happened between these two extremes, whenenhance your ability to succeed.