It’s only natural to think that a revolutionary communications technology like the internet will help break down barriers between people and bring the world closer together. But that’s not the only scenario, or even the most likely one. The internet turns everything, from knowledge-gathering to community-building, into a series of tiny transactions – clicks – that are simple in isolation yet extraordinarily complicated in the aggregate. Research shows that very small biases, when magnified through thousands or millions or billions of choices, can turn into profound schisms. There’s reason to believe, or at least to fear, that this effect, inherent in large networks, may end up turning the internet into a polarizing force rather than a unifying one.<\/p>\n
In a 1971 article titled “Dynamic Models of Segregation,” Thomas Schelling<\/a>, winner of the 2005 Nobel Prize for economics, offered a fascinating reappraisal of the segregation of communities along racial lines, illustrating the way biases are magnified through a kind of network effect. If asked what lies behind racial segregation, most of us would likely point to prejudice and discrimination. But Schelling, through a simple experiment, showed that extreme segregation may have a much more innocent cause. Mark Buchanan summarized Schelling’s findings in his 2002 book Nexus<\/a>:<\/p>\n Schelling began by imagining a society in which most people truly wish to live in balanced and racially integrated communities, with just one minor stipulation: most people would prefer not to end up living in a neighborhood in which they would be in the extreme<\/em> minority. A white man might have black friends and colleagues and might be happy to live in a predominantly black neighborhood. Just the same, he might prefer not to be one of the only<\/em> white people living there. This attitude is hardly racist and may indeed be one that many people – black, white, Hispanic, Chinese, or what have you – share. People naturally enjoy living among others with similar tastes, backgrounds, and values.<\/p>\n Nevertheless, innocent individual preferences of this sort can have startling effects, as Schelling discovered by drawing a grid of squares on a piece of paper and playing an illuminating game. On his grid, he first placed at random an equal number of black and white pieces, to depict an integrated society of two races mingling uniformly. He then supposed that every piece would prefer not to live in a minority of less than, say, 30 percent. So, taking one piece at a time, Schelling checked to see if less than 30 percent of its neighbors were of the same color, and if this was the case, he let that piece migrate to the nearest open square. He then repeated this procedure over and over until finally no piece lived in a local minority of less than 30 percent. To his surprise, Schelling discovered that at this point the black and white pieces not only had become less uniformly mixed but also had come to live in entirely distinct enclaves. In other words, the slight preference of the individual to avoid an extreme minority has the paradoxical but inexorable effect of obliterating mixed communities altogether.<\/p><\/blockquote>\n Buchanan sums up the lesson of Schelling’s experiment: “Social realities are fashioned not only by the desires of people but also by the action of blind and more or less mechanical forces – in this case forces that can amplify slight and seemingly harmless personal preferences into dramatic and troubling consequences.” (You can download<\/a> a piece of Windows-only software to perform the Schelling experiment yourself.) In the real world, with its mortgages and schools and jobs and moving vans, the “mechanical forces” of segregation move fairly slowly; there are brakes on the speed with which we pull up stakes and change where we live. In internet communities, there are no such constraints. Making a community-defining decision is as simple as clicking on a link – adding a feed to your blog reader, say, or a friend to your social network. Given the presence of a slight bias to be connected to people similar to ourselves, the segregation effect would thus tend to happen much faster – and with even more extreme consequences – on the internet.<\/p>\n