Social network science offers a completely new way of looking at human
behavior, two scholars say, because it examines both individuals and
groups, and seeks to understand the intricate, complex and surprising
processes by which we become interconnected.
increasingly view forest fires, earthquakes, revolutions and financial
crashes as "bursts of activity in a larger system intelligible only when
studied in the context of many examples of the same phenomenon," Nicholas Christakis
and James Fowler
While scientists used to study things by taking them apart, they say,
science is now trying to figure out how things fit together-molecules
into cells, neurons into brains and species into ecosystems-and
understand the rules that govern interconnection and coherence.
Discovering how networks of individuals and groups form, evolve and act
is part of that larger trend.
Christakos, a physician,
sociologist and professor at Harvard University, and Fowler, an
associate professor of political science at the University of California
at San Diego, published groundbreaking research in the July 2007 New England Journal of Medicine
demonstrating that obesity is contagious. Their provocative new book, Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives
describes meticulous multi-disciplinary research, fascinating
observations and history suggesting that all kinds behavior and emotions
ripple through networks. Smoking, drinking, happiness, loneliness,
political views, the likelihood of voting, the creativity of inventors,
and word of mouth messages are all subject to the unexpected and
nonlinear influences of our often unrecognized social connections.
the authors suggest, social networks are part of our ancient biological
heritage, and our position in our networks may be to some degree
impacted by our genes and other circumstances beyond our control. Their
compelling ideas and informed insights make lively reading. They cite
the theory of primatologist Robin Dunbar
who argues humans developed language to manage social complexity.
Dunbar thinks language in humans evolved as an efficient replacement for
grooming, the method other primates used to establish social cohesion.
Language skills facilitate the constant cooperation and competition,
abstract reasoning, insights, and empathy, demanded by human social
networks of unrelated individuals. Of course there were long range
unintended consequences. Once language served for small scale
interactions, the authors say, "we were free to do other things with it,
like write poetry-just as feathers evolved to keep prehistoric
reptiles warm but they wound up using the innovation to fly."
neurons may be one mechanism of behavioral contagion. If you yawn when
someone else yawns, and the sight of pain makes you wince, your mirror
neurons are working. Facial expressions and responses to them may be
another route. The authors note that when people imitate facial
expressions of others, the signal passes from the facial muscle to the
brain, rather than the more usual pathway from the brain to the muscle.
They cite an experiment in which subjects listened, without speaking
themselves, to recorded nonverbal vocalizations of otheres reacting to
amusement and triumph and fear and disgust. The subjects' brains,
monitored by MRIs, showed the sounds stimulated parts of the brain that
control corresponding facial expressions.
The author's "Three Degree Rule" says everything we do
affects our immediate family and friends, our friends' friends, and our
friends' friends' friends. After that, our influence dims. But networks
are dynamic, and they change as people move, get divorced, die, or adopt
different behavior and interests. Their discussion of the impact within
networks of gender, relationship, who identifies who as a friend and
whether it is mutual, is fascinating and counterintuitive. According to
their models, weight loss efforts might work better with a friend of a
friend, rather than a friend, and you can be saddened by the unhappiness
of someone you don't even know.
This work extraordinary
implications for public health. For instance, should immunizations be
given to be people with the most contacts rather than an entire
population? Should weight loss efforts be directed toward those likely
to have the most impact on their networks? Those aren't the only
ethical and philosophical issues Christakis and Fowler raise. They say
genes play a complicated role in how well connected we are, and where we
are in network. They studied 1,100 twins drawn from a sample of 90,115
adolescents, and found genetic factors accounted for about 46 percent of
variations in popularity. A kid with five friends had a different
genetic makeup from a person with one friend. A person in the center of
the network tended to have a genetic makeup that differed from a person
at the periphery. And a person with five friends who know each other
differed genetically from a person with five friends who don't.
findings raise questions of fairness and equality, and more, they say.
Does one deserve credit or blame for network-influenced good and bad
behavior? If networks constrain our information and choices, do we have
free will? Some answers may lie in deeper understanding.
transformations will come from electronic networking? The answer is
unknowable right now, but Christakis and Fowler note that evolutionary
biology teaches us humans emerged in small groups where everyone was
connected to everyone else by three degrees or less. That appears to be
an important part of the way networks work, they say, andit may
constrain our ability to connect even though technology gives us access
to vastly larger numbers of people. In their study of college Facebook
users, the students had an average of 110 friends, but of those, only
6.6 were close friends. That's not too far from Robin Dunbar's theory
that the expected size for an interconnected human group would be about
150-about the size of Neolithic village or a Roman army unit-and that
the size of a conversational group would be about four.
authors suggest there is something powerful and positive in realizing
the ways we are all intertwined, and even critics are captivated by
their writing and research. Read a New York Times Magazine story
and Wired review.
You won't want to put this book down, but you might want to give copies
as holiday gifts that will please your friends' and make your friends'
friends' friends happy.