Connect to the world
Modern writing in the social sciences can be placed into one of three categories. The first category, which is vast, consists of the arcane and the incremental - those studies so obscure, or which advance scholarship so infinitesimally, that they can be safely ignored by the general reader. The second category consists of statistical proof of the obvious. And in the third category, which is surely the smallest, are works of brilliant originality that stimulate and enlighten and can sometimes even change the way we understand the world. “Connected,” by Nicholas A. Christakis and James H. Fowler, is full of this kind of research. “What a colossal waste of money it is for social scientists to prove the obvious,” the authors themselves write, characterizing a typical response they got to an attention-grabbing study they published two years ago.
As Christakis and Fowler (along with other researchers) have found, obesity spreads by contagion. So if your friend’s friend’s friend - whom you’ve never met, and lives a thousand miles away - gains weight, you’re likely to gain weight, too. And if your friend’s friend’s friend loses weight, you’re likely to lose weight, too.
Christakis and Fowler explore network contagion in everything from back pain (higher incidence spread from West Germany to East Germany after the fall of the Berlin Wall) to suicide (well known to spread throughout communities on occasion) to sex practices (such as the growing prevalence of oral sex among teenagers) to politics (where the denser your network of connections, the more ideologically intense and intractable your beliefs are likely to be).
How does network contagion work? What is the mechanism whereby your friend’s friend’s obesity is likely to make you fatter? Partly, it’s a kind of peer pressure, or norming, effect, in which certain behaviors, or the social acceptance of certain behaviors, get transmitted across a network of acquaintances. In one example the authors give, Heather stops exercising and gains weight, which influences her friend Maria’s thinking about what normal weight is, so that when Maria’s other friend Amy (who has never met Heather) also stops her exercise regime, Maria is less likely to urge Amy to resume it.
During the early stages of human evolution, selective advantage was probably conferred on those individuals who lived in social networks and could share information about food or predators. The primatologist Robin Dunbar has argued that the human brain evolved to its present size to keep track of a network of 150 people. As among primates, those humans who are best able to manipulate social networks to their advantage thrive, and that ability may be genetically encoded. Using a clever study of young twins, the authors observed that genes accounted for “46 percent of the variation in how popular the kids were.”
Network science has implications for public policy. By learning more about the structure of various networks, we can identify where the hubs are - the most “influenceable” nodes that are likely to spread an idea (or a behavior or a germ) quickest - and intervene at those points to stop the spread of, say, an unhealthy behavior (like smoking or overeating or suicide), or to promote a positive one (like voting or becoming an organ donor), or to vaccinate more efficiently against disease.
As described by the authors, network science has potential to be used for good. But then again, if all the strutting and fretting that we believe to be the product of our individual free will is really only the antlike scurrying of a collection of nodes, can anyone really be said to “use” the network? You could have the book HERE.
READ ELSE BOOKs:
Barack Obama Book; The Audacity of Hope.
