Six Degrees: The Science of a Connected Age

I wrote this book review as an assignment for a class. Its intended audience was sociologists unfamiliar with network theory. The intended audience for the book though is much wider. If you want the math, read academic journals. In the first chapter of Six Degrees Duncan Watts notes that gossip, power outages, epidemics, even properties of the human brain such as consciousness are phenomena that may be understood as emerging from the interaction of their constituent elements. Through such examples, he calls attention to the broad applicability of his subject matter. Having provided this motivation, Watts spends much of first half of the book discussing what he knows best, "small world" networks. In the second half he presents a network perspective for a wide range of topics such as epidemics, externalities, speculation, social decision making, and organizations. Like many academics marketing books to non-academics, Watts skillfully weaves his personal story with the science. His personal story is not only provided to keep laymen interested. Watts is now a member of the sociology department at Columbia University, but one can't help but wonder whether he identifies as a sociologist? How would other members of the discipline respond to a youngster whose PhD is in theoretical and applied mechanics who may never have read Durkheim? His early collaborators were mathematicians, physicists, and computer scientists lodged in appropriate departments. Watts though, has become a strong proponent of interdisciplinary science, and he respectfully acknowledges research that has been done in anthropology, sociology, psychology and economics. His first foray in the social sciences was inspired by the "small world" phenomenon. When two people are surprised to learn they have mutual acquaintances, someone often says, "It's a small world." In 1967, social psychologist Stanley Milgram decided to investigate how small the world really is. He tasked randomly selected residents of Boston and Omaha with getting a letter to a stockbroker who lived in Massachusetts. The rule was, they could only send the letter to people they knew on a first name basis. Amazingly, the letters that reached their destination usually did it in just 6 steps. This finding was then misconstrued and became the urban legend that there are six degrees of separation between any two people. Despite the widespread interest in the small world phenomena, little progress was made understanding it over the next thirty years. Watts got interested in this problem when he was a graduate student in theoretical and applied mechanics. He and his advisor, Steven Strogatz, had been trying to understand how crickets' chirping becomes synchronized without a conductor cricket. Watts surmised that the timing of a cricket's chirp must be influenced by where it is located and the other crickets it is listening to. The ability to synchronize may depend on the structure of this network of

I've always been fascinated by social networks, having read Granovetter's work on strong vs. weak ties. As a career coach, I naturally talk to clients about the joys and frustrations of networking -- and I loved the movie "Six degrees of separation."If you're looking for an easy piece of entertainment, this is not the book for you. Watts shows how this field has advanced by combining research efforts in information science, physics, mathematics and sociology. We look over his shoulder as he collaborates with other scientists to solve tough problems -- and get a glimpse of modern science in action (although I think Watts emphasizes the more positive, cooperative aspects of "doing science"). Students of psychology will enjoy his discussion of Milgram's famous experiment -- messages mailed to a Boston stockbroker -- and the real, as compared to legendary, results. Milgram's even more outrageous obedience experiment, which Watts includes, also deserves a footnote: subjects refused to obey (a) when the experimenter broke the rules and gave reasons for the order and (b) when they were able to reconstruct their roles outside the laboratory. I began by borrowing this book from a library but realized that it needs to be owned. It's not a quick, one-time read. Although it's accessible, you have to pay attention and I found a need to read sequentially, from chapter to chapter. But if you read carefully, you'll change the way you look at the world. As other reviewers have noted, Watts shows how daily life is influenced by properties of networks: Why do some viruses, computer and biological, spread, and why others come to a quick halt? Why do airline hub-and-spoke networks often break down? How do computer searches work and what makes them effective?We're living in an increasingly connected world and this book will help us see and understand the connections more clearly. I think it's a must for anyone who wants to comprehend our world today.

Duncan Watts' book Six Degrees is a fascinating look at the early days of a "new" science. The book takes its title from Six Degrees of Separation (or Six Degrees of Kevin Bacon if you prefer) and examines the small-world concept in a number of different networks....both social and technological. The book also explains the research that indicates that we should expect many, if not most, networks to demonstrate such properties.The book is also a wonderful look at the process of scientific discovery. It highlights the growing importance of interdisciplinary work in tackling many of today's problems. Physicists and mathematicians may have much to say on this new science, but especially when looking at human networks, the social scientists have their own unique contributions to make. You also get to see the "small world" in action as chance encounters play an important role in the story. I also agree with several of the other critiques of an earlier review about the author's arrogance or lack thereof. I thought Mr. Watts was very generous in highlighting the contributions of both his predecessors as well as his contemporaries. Even noting several times that he should have thought of something, but hadn't. That said, is Mr. Watts enthusiastic about and proud of his work? Absolutely. And I think that is great... we ought to love what we do for a living and be genuinely excited about sharing it with others. Only time will tell how important this new science of networks turns out to be. But I am glad that Mr. Watts chose to write this book and I recommend it highly.

Contrary to some recent remarks from an apparently aggrieved reader, I think Six Degrees is actually quite different from most books claiming to cover new and exciting scientific developments. Far from being self-aggrandizing, I found it's tone remarkably humble and generous to others. Watts, in fact, is the first person to call his subject the "new" science of networks, and goes to considerable lengths to acknowledge, even glorify, his intellectual predecessors. He doesn't mention every scientist who has made contributions: it's not meant to be a text book, thankfully.Watts also has bigger fish to fry than simply the importance of networks in everything under the sun. His real message is that social reality has to be understood both in terms of the way people are connected and also the way they behave. So focusing on individual behavior to the exclusion of their interactions misses half the story, but so does just focusing on the interactions (as much of network theory has done). It's true that many of the ideas are quite old (and Watts again is the first to point this out), but the way they are put together is new, and that is what is so interesting about it.The results are often quite deep and thought provoking, which means you have to actually read the book to understand what's in it, but Watts always comes up with an entertaining anecdote or analogy to make even the hardest concepts palatable and interesting. Overall, it's a great, fun read about a fascinating subject that really makes you think. And what more can you ask from a book?

I enjoyed reading this book and recommend it higly to anyone who would like to know why this "world" is so small. I completely disagree with one reviewer in his comments that the author of this book suffers from the self-importance exultance syndrom. Yes, we have all suffered from the annoyance "larger than life" figures that some authers try to impose on us while we have been looking the hidden beef. But, not in this case. In fact, I feel the presentation is thoughtful and humble. Moreover, the writing is elegant, lucid and crisp. The book gives a clear picture of an imprtant emerging field, provides the background of where it came from, and give a vision of how it may evolve. I cannot but admire the creativity, diligence and the vision of the author.Putting down the book, I can still hear the echo of the gasp the auther uttered, "How did we miss that?" How can this not be a good read?