The Ecosystems of Simple and Complex Societies: Social and Geographical Dynamics

Abstract

We present a spatial agent-based model of the emergence and proliferation of premodern complex societies in an isolated region initially inhabited by simple societies. At the intrasocietal level, the model integrates scalar stress, social fission, sociocultural evolution, societal collapse, and Malthusian-Ricardian demographic dynamics. At the geographical level, the model includes warfare for territory and captives, territorial division due to social conflict, and territorial disintegration due to collapse. We found that a single variableslow, continuous progress in intensive agriculture-drives the social and geographical dynamics. Consistent with the archaeological and historical record, the model produced three consecutive "eras": During the first era, simple societies dominate the region. They use extensive food production methods. Small complex societies of intensive agriculturists emerge intermittently in the core land, where intensification is feasible. Shortly a er, they collapse or are annihilated by local simple societies. During the second era, some complex societies avert early collapse and annihilation. They expand by conquest. At all times, they coexist with simple societies. Some complex societies are destroyed in war; others collapse. From time to time, complex societies collapse en masse. During the third era, there are no more mass collapses. Complex societies slowly expand until they dominate the core land. Simple societies take refuge in the marginal land, where intensification is infeasible. Simple and complex societies coexist, separated by a moving frontier. In an ebb and flow, complex societies expand to the marginal land and withdraw to the core land. The results of the simulations are qualitatively consistent with prehistorical and historical case studies. The model replicates the progression from simple to more complex societies, and explains why that progression happened in fits and starts.

A Dynamic Network Model of Societal Complexity and Resilience Inspired by Tainter’s Theory of Collapse

“…This finding contrasts with our result for two specific reasons: First, in Guzmán et al [ 52 ], complexity is a binary state and cannot continue to increase once a society is denoted as being complex . Second, and more importantly, Guzmán et al [ 52 ] modeled a warrior class comparable to administrators in our model, which was directly coupled to available food (energy). Therefore, complexity in terms of hierarchies could not exceed the level of energy available and thereby grew to an unsustainable size.…”

“…In addition, we found that the absence of an elite (i.e., egalitarian society), which is comparable to the random status exploration mechanism in our model, produced more pathways to avoid collapse than a hierarchical (complex) society. In comparison, previously reported simulations of competing premodern societies showed that collapse becomes less likely as societies grow more complex and develop intensive agriculture at sufficiently large scale [52]. This finding contrasts with our result for two specific reasons: First, in Guzmán et al [52], complexity is a binary state and cannot continue to increase once a society is denoted as being complex.…”

A dynamic network model of societal complexity and resilience inspired by Tainter's theory of collapse

“…egalitarian society), which is comparable to the random state exploration mechanism in our model, produced more pathways to avoid collapse than a hierarchical (complex) society. In comparison, previously reported simulations of competing pre-modern societies showed that collapse fades once societies become complex and can develop intensive agriculture at sufficiently large scale (Guzmán et al, 2018). This finding contrasts our result for two specific reasons: First, in Guzmán et al (2018) complexity is a binary state and cannot increase further once a society is denoted as being complex.…”

“…In comparison, previously reported simulations of competing pre-modern societies showed that collapse fades once societies become complex and can develop intensive agriculture at sufficiently large scale (Guzmán et al, 2018). This finding contrasts our result for two specific reasons: First, in Guzmán et al (2018) complexity is a binary state and cannot increase further once a society is denoted as being complex. Second and more importantly, Guzmán et al (2018) model a warrior class comparable to administrators in our model, which is directly coupled to available food (energy).…”

“…This finding contrasts our result for two specific reasons: First, in Guzmán et al (2018) complexity is a binary state and cannot increase further once a society is denoted as being complex. Second and more importantly, Guzmán et al (2018) model a warrior class comparable to administrators in our model, which is directly coupled to available food (energy). Hence complexity in terms of hierarchies cannot exceed the level of existing energy and thereby grow to an unsustainable size.…”