This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
Science and common sense are alike grounded in human experience. Yet these ways of thinking about things are often in conflict. Sometimes the simplicity of most commonsense explanations can make it hard to win people over to the complexity and uncertainties of most scientific arguments.
Consider the textbook case of the mathematician and astronomer Nicolaus Copernicus (1473–1543). For centuries, making accurate predictions about where the planets would be on any given night was anything but a piece of cake. The irony is that the calculations involved were so challenging because everyone was accepting as the gospel truth the mistaken but commonsense idea that Earth sits motionless at the center of the universe while the sun, moon and planets move around us.
Similarly, the Darwinian revolution of the 19th century challenged not only the conviction that we live at the center of things, but also that we are the lead characters in the story of life on Earth. Many still do not accept Darwin’s insight that all life on our planet has evolved by means of natural selection.
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In contrast to the cognitive revolutions triggered by Copernicus and Darwin, today’s seemingly pedestrian worries about issues such as net neutrality or Facebook privacy may seem inconsequential. Yet both are contemporary signs that there is another cognitive revolution in the making.
Modern research in sociology, psychology, neuroscience, and anthropology is showing that our world does not revolve around ourselves as individuals—contrary to Enlightenment and later claims that we are inherently self-centered creatures. Instead, what we are like as individuals critically depends on how we are linked socially and emotionally with others in relational networks reaching far and wide.
Why? We have evolved as a species to be quintessentially social creatures. Many plausible explanations have been proposed for why we are so. The bottom line, however, is a telling one. As the psychologists Lane Beckes and Jim Coan have observed, being a social animal gives us real advantages in the struggle for existence—a social baseline of emotional support and security. So much so, that perhaps far more than most of us realize, our human connections with others are in effect an extension of the way our brain interacts with the world.
Science and philosophy today are grappling with some of the larger implications of this view of life. For instance, the anthropologist Fredrik Barth once remarked that practically all social science reasoning rests on the idea that there are discrete groups of people on Earth that can be variously labeled as populations, ethnic groups, societies, cultures, or races.
This commonsense understanding of human diversity—often called typological or categorical thinking—takes it as self-evident that things naturally come in different kinds, or types, that can be labeled as such. From this perspective, the words we use to describe things are like empty containers into which we can put things once we have grasped the essential “meaning” of these verbal containers.
Adopting a networks perspective, however, changes how we see the world and our place in it. Take the contentious issue of race. From a commonsense perspective, it seems obvious that different kinds of people live in different parts of the globe. Who could possibly mistake people from African, Asian or Irish descent? From a networks perspective, however, it is a no-brainer to see that everybody on Earth is linked with everyone else by “six degrees of separation.”
Or consider why some of us are fatter than others. The commonsense answer is that some of us eat too much. But why? As part of the Framingham Heart Study, Nicholas Christakis and James Fowler learned using network approaches that individual weight gain in a social network of over 12,000 people was associated with weight gain in their spouses, friends, siblings and neighbors even beyond the level of direct social contact—people you have never met face to face may influence how well you keep to a desired weight.
Finally consider the spread of ideas via social networks. Common sense tells us that people with the strongest ties with others ought to be the most influential people to have around when, say, you are launching a new product or trying to convince others to accept a new idea. Network research, however, has shown that it is those who have weaker ties with others outside their immediate social circle who are actually in the best position to get the word out.
The impact of our social networks on our lives can be substantial. For example, close-knit groups having few ties with others beyond the immediate circle of friends, relatives or colleagues can become breeding grounds for odd and sometimes harmful ideas and practices—such as the contagious suicides reported among teenagers in places as culturally and geographically disparate as urban North America and Micronesia.
This shift in thinking is not only happening in the social sciences. Networks are also having a major impact in the biological and physical sciences. Take that well-known most basic unit of our biological selves, the gene. It has become common sense to think that genes encode everything from our hair color to our propensity for wearing rubber bands on our wrists. However, evolutionary biologists are now modeling series of complex networked relationships at multiple levels ranging from individual “letters” in the genome to protein-gene networks to interaction networks between organisms, thereby demonstrating that our genes are only our destinies to the extent that they link to each other and to the surrounding world—both social and natural.
Network thinking lets us scientifically understand the world around us as one of connections that shape observed phenomena, rather than as one where the intrinsic properties of people, genes, or particles determine outcomes. Like previous scientific revolutions, the network revolution also has the promise of reshaping our basic commonsense expectations of the world around us, and may allow us to recognize that we are not a basically individualistic, asocial, and quarrelsome creature that comes in bounded linguistic, ethnic, racial, or religious types, but a social species linked to one another by far-reaching network ties.