Mark Buchanan’s Nexus: Small Worlds and the Groundbreaking Science of Networks is an excellent piece of science writing; it’s the best introduction I have found so far to the recent developments in network theory: discoveries about how networks are structured to permit no more than “six degrees of separation” between any point and any other point, and how “tipping points” develop, at which small changes have very large consequences. These theories are extending our understanding of how patterns work: how the same forms of emergent order can be found in ecosystems, in economies, in neural structures in the brain, and so on. The material is different in each case, but the mathematics is the same. I find these developments exciting, while at the same time I remain a bit skeptical, feeling that such results can easily be oversold….
Buchanan illustrates the problems I have with network theory very clearly, when he writes about Thomas Schelling’s use of network theory to explain housing segregation in the US.
Buchanan writes, paraphrasing Schelling: “What is the origin of racial segregation, for example? In the United States, the persistence of segregation is usually attributed to racism or biased practices on the part of the government or the real estate industry. But another less obvious factor may be equally influential” (185).
This other factor is that, according to Schelling’s simulations, if we merely assume that “most people would prefer not to end up living in a neighborhood in which they would be in the extreme minority,” then even small changes in the racial makeup of a neighborhood will be amplified, until the neighborhood is all white or all black. (Sort of like what apparently happened in Detroit, in the 1960s and 1970s). Such a preference, Buchanan naively adds, “is hardly racist,” since “people naturally enjoy living among others with similar tastes, backgrounds, and values.”
I am not contesting Schelling’s mathematics, which indicates that even given a 70/30 racial split, the extremely slight preference people have for living among “their own” race will lead to total segregation rather quickly. What’s dubious about the argument is the founding assumption about race. Why race should be so important is not addressed. What’s troubling about Buchanan’s account of Schelling’s findings (I have not read Schelling himself) is that he concludes from it that “even if every trace of racism were to vanish tomorrow, there may still be a natural tendency for races to separate, much like oil and water.” The “action of more or less blind and mechanical forces,” amplifying “seemingly harmless personal preferences,” would lead to this result.
Such an argument is utter nonsense. For “if every trace of racism were to vanish,” then segregation along racial lines would no more result from “seemingly harmless personal preferences,” than, say, segregation between left handers and right handers, or between tall people and short people, or between blond white people and brunette white people happens today. Buchanan is unable to think outside the contemporary norms of race, which he perpetuates by his example.
What this “slip” on Buchanan’s part indicates, I think, is that materiality, or content, matters. The recent scientific discoveries about mathematical patterns that seem to recur in all different sorts of matter are important; but we shouldn’t delude ourselves that they are everything.