Spatial aggregation and scaling of human networks in history

Our research program addresses the emergence of human social complexity in a new and productive way. Recent studies of the dynamics of human agglomeration using the framework of scaling analysis demonstrate that there is great utility in conceptualizing human societies in terms of the aggregate properties of social and infrastructural networks. Through a combination of painstaking empirical work and the application of ideas from complex systems, a theoretical framework is emerging that derives many aggregate properties of modern cities from first principles and yields predictions that have been borne out in a large number of empirical tests. This theory builds from basic properties of all human networks in providing an explanation for the observed elasticities in many quantities with respect to urban populations. The result is a view of cities as built environments that sustain greater degrees of connectivity and faster rates of social interaction, thus enhancing the division of labor and increasing innovation rates and productivity, but also rates of crime and disease. We seek to generalize and test these ideas on a wider range of societies as a step in building a general theory of human societies as complex systems.

Three points argue that our program of research on the scaling of human agglomerations in pre-modern systems is worthwhile and feasible, but also challenging. First, the parameters of emerging theory do not invoke specific characteristics of capitalism, industrialization or democracy, but instead focus on generic properties of all human networks. As a result, urban scaling models, suitably-modified, may apply broadly to human aggregations across time and space. Second, initial analyses of archaeological data support the hypothesis that scaling phenomena occur in a wide range of human systems, and the exercise has also proven to be theoretically-productive. Third, we have found that appropriate data for scaling analysis are difficult to obtain for many pre-modern systems for a variety of reasons. In short, a historical and comparative perspective on settlement scaling is crucial for continued development of this framework, but accomplishing this goal will require significant additional investment.

We are therefore engaged in an integrated program of research that involves: 1) the generalization of urban scaling theory to encompass all forms of human agglomeration in the past and present; and 2) compilation and analysis of archaeological and historical data from systems that are useful for probing details and exposing blind spots in the theory. Theoretically, we focus on the determinants of the pre-factors of scaling relations, factors that define the limits of settlement populations, and the extent to which scaling effects are realized in systems with slower aggregation rhythms than are typical of modern systems. Empirically, we focus on compilation and analysis of data from Ancient Greece and Rome, Medieval Europe, Mesoamerica, the Andean region, and native North America. In this way, we will build a more encompassing settlement scaling theory that sheds new light on the evolution of social complexity.