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Review: Connected, by Nicholas A. Christakis and James H. Fowler

Social networking - which encompasses everything from Twitter and Facebook to good old-fashioned instant messaging - has become fairly mainstream over the past year or so, with references to Twitter and Facebook showing up in coverage of Barack Obama's presidential campaign, on Oprah and even in TV sitcoms.

Some cultural critics argue that this phenomenon represents a lot of sound and fury, signifying nothing. But a new book by a Harvard doctor and a political scientist argues that the impulse behind social networking is fundamental to who we are as human beings, and that connections formed through such activities may be responsible for whom we marry, how much we weigh and how long we live.

Connected was written by Nicholas Christakis - a doctor and professor of medicine and sociology at Harvard - and James Fowler, an associate professor at UCSD in political science. The book's subtitle is The Surprising Power of Our Social Networks and How They Shape Our Lives. However, while the book is well put together, and the science behind it appears to be impeccable, it's probably pushing things to call its conclusions "surprising."

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In fact, much of the book is spent erecting an elaborate scaffolding of numbers in order to describe behaviour that has become so commonplace we don't even think about it any more.

As many books aimed at popularizing scientific research do, the authors start each chapter with an anecdote that supposedly encapsulates the thesis, but these little vignettes often do little to support their conclusions. The first chapter, for example, begins with a discussion of a blood feud in Italy in the 1840s in which two families killed various brothers and sons and cousins. It's very colourful, but what does it say about "the power of social networks and how they shape our lives?" The authors say it proves that "violence can spread through social ties," but that hardly seems like something that requires proving, particularly in 19th-century Italy.

It's nice that they have gone to the trouble to provide some mathematical and statistical support for what we all instinctively know

The authors do a nice job of summing up and expanding on a host of social-networking research, from Mark Granovetter's theory of "weak ties" to Robin Dunbar's theories about the maximum number of people that the average person can maintain meaningful social contact with. And they spend a fair amount of the first part of the book describing the structure of different networks, although they show a distinct fondness for quasi-scientific terms such as "hyperdyadic spread" and "prosopagnosia" (the inability to detect a change in facial expressions).

It's tempting to come to the conclusion that the authors couch what they are describing in such arcane terms because so much of it is blindingly obvious, such as the idea that who we live near might affect how we vote, or how we dress, or behave towards others. Sociologists have been studying these kinds of phenomena since the 1960s, when Stanley Milgram did his famous "Six Degrees of Separation" research (the authors have come up with their own version, saying the effects they notice dissipate after just three degrees).

The two conclusions that form the core of this book, and for which Christakis and Fowler are the best known, are that both happiness and obesity are catching, and that you are more likely to be happy or obese not only if your friends are, but if your friends' friends are as well. Much statistical heavy lifting occurs in order to justify these conclusions, producing statements such as "mathematical analyses ... suggest you are 15 per cent more likely to be happy if a directly connected person is happy," etc. The authors go on to extend this principle to everything from being wealthy to living longer.

But as the authors themselves remind us from time to time, these types of phenomena are hardly unknown. It's nice that they have gone to the trouble to provide some mathematical and statistical support for what we all instinctively know: that if you hang around happy people, you are more likely to be happy, and if you hang around or know a lot of wealthy people, you're more likely to become wealthy. Or to quote the book: "real-world social connections have an effect on how we feel," and "it is clear that people rely heavily on friends and family for all kinds of relationships." Are these the "startling findings" described in the flyleaf?

Perhaps compelled to try and find something provocative in all of this, the two doctors go so far as to suggest early on that the effect of social networks and connectedness on human behaviour suggest "people do not have complete control over their own choices," which sounds suspiciously like social determinism (the defence that "society made me fat"). Towards the end, meanwhile, the authors state that social networks come close to having some kind of innate intelligence of their own, and that they could be forming a kind of intelligent "super-organism" that could transform the planet.

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Thankfully, neither of these ideas are developed much further in the book, since both are fairly alarming coming from reputable social and medical scientists. What we are left with is a solidly scientific - if somewhat tedious - book that appears to prove many of the things you already believe about human social behaviour.

Mathew Ingram is the Communities Editor at the Globe and Mail.

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