Six Degrees: The Science of a Connected Age

262 Pages·2004·2.19 MB·English

by  Duncan J. Watts

PRAISE FOR DUNCAN WATTS’S SIX DEGREES
“Watts smoothly combines a historical survey of the field with real-world
examples, often drawn from his personal experience. Well-done [and]
comprehensive.”
—Kirkus Reviews, starred review “[A] fascinating and completely approachable
introduction to the science of networks…. This book is of great importance for a
number of reasons. First, Watts offers an introduction to a very complicated field
that is both deeply insightful and a pleasure to read. Second…Watts offers
sufficient detail and nuance that give the work a profound impact. This book
offers a depiction of the social and physical worlds that is amazing and
intellectually stimulating.”
—Virginia Quarterly Review
“This is an exciting book by one of the world’s pioneering young scientists.
Watts’s insights into the interconnections that bind us together—from the links
on the World Wide Web to the major global hubs of transport and finance to the
sexual networks that transmit the AIDS pandemic around the world—offer a
vital new framework for understanding our global society and its dynamic
change. Watts explains how we are all closely connected in our ‘small worlds,’
and with this book you will be connected to the world’s leading thinkers in the
exciting new field of network theory.”
—Jeffrey D. Sachs, director of the Earth Institute, Columbia University “This is
a story that is both personal and remarkable for its ability to convey the wonder
of complex science. A fascinating endeavor!”
—Bill Miller, CEO, Legg Mason Funds, Inc.
“An interesting look at the many networks of this ‘connected age’ and the
implications and complications that surround identifying and quantifying them.”
—R. F. Conklin, Choice
“Because Watts explains [this] phenomenon…in accessible terms, a great many
readers will accept his invitation to explore the frontiers of a new intellectual
enterprise.”
—Booklist
“Watts’ inviting approach shapes its ordered moves into a package more dashing
than dry.”
—The Onion
“An admirable effort.”
—Publishers Weekly
“A fascinating, often first-person look at the emerging science of networks.
Readers will certainly learn a lot about networks from Six Degrees, for Watts is
a gifted teacher. But Six Degrees is even more useful as a window into the
emergence of a new scientific discipline.”
—Research News and Opportunities in Science and Technology
Six Degrees
THE SCIENCE OF A CONNECTED AGE
Duncan J. Watts
W. W. NORTON & COMPANY
NEW YORK LONDON
For
Mum and Dad
“I read somewhere that everybody on this
planet is separated by only six other people. Six
degrees of separation. Between us and
everybody else on this planet.”
—Ouisa, in
SIX DEGREES OF SEPARATION,
by John Guare
Contents
PREFACE
CHAPTER 1: The Connected Age
EMERGENCE
NETWORKS
SYNCHRONY
THE ROAD LESS TRAVELED
THE SMALL-WORLD PROBLEM
CHAPTER 2: The Origins of a “New” Science
THE THEORY OF RANDOM GRAPHS
SOCIAL NETWORKS
THE DYNAMICS MATTERS
DEPARTING FROM RANDOMNESS
HERE COME THE PHYSICISTS…
CHAPTER 3: Small Worlds
WITH A LITTLE HELP FROM MY FRIENDS
FROM CAVEMEN TO SOLARIANS
SMALL WORLDS
AS SIMPLE AS POSSIBLE
THE REAL WORLD
CHAPTER 4: Beyond the Small World
SCALE-FREE NETWORKS
THE RICH GET RICHER
GETTING RICH CAN BE HARD
REINTRODUCING GROUP STRUCTURE
AFFILIATION NETWORKS
DIRECTORS AND SCIENTISTS
COMPLICATIONS
CHAPTER 5: Search in Networks
SO WHAT DID MILGRAM REALLY SHOW?
IS SIX A BIG OR A SMALL NUMBER?
THE SMALL-WORLD SEARCH PROBLEM
SOCIOLOGY STRIKES BACK
SEARCH IN PEER-TO-PEER NETWORKS
CHAPTER 6: Epidemics and Failures
THE HOT ZONE
VIRUSES IN THE INTERNET
THE MATHEMATICS OF EPIDEMICS
EPIDEMICS IN A SMALL WORLD
PERCOLATION MODELS OF DISEASE
NETWORKS, VIRUSES, AND MICROSOFT
FAILURES AND ROBUSTNESS
CHAPTER 7: Decisions, Delusions, and the Madness of Crowds
TULIP ECONOMICS
FEAR, GREED, AND RATIONALITY
COLLECTIVE DECISIONS
INFORMATION CASCADES
INFORMATION EXTERNALITIES
COERCIVE EXTERNALITIES
MARKET EXTERNALITIES
COORDINATION EXTERNALITIES
SOCIAL DECISION MAKING
CHAPTER 8: Thresholds, Cascades, and Predictability
THRESHOLD MODELS OF DECISIONS
CAPTURING DIFFERENCES
CASCADES IN SOCIAL NETWORKS
CASCADES AND PERCOLATION
PHASE TRANSITIONS AND CASCADES
CROSSING THE CHASM
A NONLINEAR VIEW OF HISTORY
POWER TO THE PEOPLE
ROBUSTNESS REVISITED
CHAPTER 9: Innovation, Adaptation, and Recovery
THE TOYOTA-AISIN CRISIS
MARKETS AND HIERARCHIES
INDUSTRIAL DIVIDES
AMBIGUITY
THE THIRD WAY
COPING WITH AMBIGUITY
MULTISCALE NETWORKS
RECOVERING FROM DISASTER
CHAPTER 10: The End of the Beginning
SEPTEMBER 11
LESSONS FOR A CONNECTED AGE
CHAPTER 11: The World Gets Smaller: Another Year in the Connected Age
FURTHER READING
BIBLIOGRAPHY