Scaling major transitions in human sociopolitical complexity

Abstract

The human species is diverse in the size, structure and complexity of our social organizations. Today, human sociopolitical complexity ranges from stateless small-scale societies to complex states that integrate millions of individuals over vast geographic areas. Here, we explore major transitions across this range of complexity. In particular, we examine the statistical structure of these transitions using Horton-Strahler branching, generalized Horton Laws, and allometric spatial mixed-effect models. We show that all major transitions in sociopolitical complexity follow an invariant fractal-like growth process; with each transition there is an additional level of jurisdictional hierarchy, a four-fold increase in population size, a two-fold increase in population area, and therefore a doubling of population density. These statistics fully describe all transitions from the least to the most complex societies. However, these transitions are probabilistic, not deterministic in nature. This fact explains the asymmetry of human sociopolitical evolution: while more complex societies were necessarily once less complex, less complex societies do not necessarily become more complex.

Institutional complexity emerges from socioecological complexity in small-scale human societies

“…All models, data and R code used to generate the results in this article are available online at https://doi.org/10.5061/ dryad.gb5mkkwz3 [40]. The data we use in this study come from Jorgensen's (1980) Western Indians [26].…”

A quantitative analysis of intensification in the ethnographic record.

“…There is growing empirical evidence that social organization across the spectrum of sociopolitical complexity may be described in terms of discrete, hierarchical, self-similar social networks. This fractal-like property has been documented in personal social networks [82][83][84], online social networks [85,86], hunter-gatherer social networks [87][88][89], small-scale autonomous village societies [90,91], self-organized settlements within nation-states [92], the urban networks and sociopolitical organization of archaic states and empires [8], and the financial, political, scientific, and communications infrastructural networks of modern nation-states [93]. Human social networks are also space-filling.…”

“…My colleagues and I recently documented that middle-range and state societies also exhibit sublinear scaling of territory size with population, indicating that human societies across the full range of sociopolitical complexity exhibit nonlinear economies of scale in land use (A = A 0 N β , β ≈ 1/2, r 2 = .95). As sociopolitical complexity and agricultural intensity increase, per capita space use decreases systematically, with a fractal-like doubling of population density with every increase in sociopolitical complexity [93]. Human social networks are thus space-filling in the technical sense.…”