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 variable---slow, 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 after, 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.

中文翻译：

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简单和复杂社会的生态系统：社会和地理动态

我们提出了一个基于空间代理的模型，该模型在最初由简单社会居住的孤立地区中，出现了前现代复杂社会。在社会内部层面，该模型整合了标量压力，社会裂变，社会文化演变，社会崩溃以及马尔萨斯-里卡德人口动态。在地理级别上，该模型包括针对领土和俘虏的战争，由于社会冲突而引起的领土划分以及由于崩溃而引起的领土瓦解。我们发现，单一变量-集约农业的缓慢持续发展-推动了社会和地理动力。与考古和历史记录一致，该模型产生了三个连续的“时代”：在第一个时代，简单的社会主导了该地区。他们使用广泛的食品生产方法。集约化农业工作者的小型复杂社会间歇性地出现在集约化可行的核心地区。不久之后，它们崩溃或被当地的简单社会所摧毁。在第二个时代，一些复杂的社会避免了早期的崩溃和歼灭。他们通过征服而扩张。它们始终与简单的社会共存。一些复杂的社会在战争中被摧毁；其他人崩溃了。复杂的社会不时地崩溃。在第三个时代，不再有大规模的坍塌。复杂的社会慢慢扩张，直到它们统治核心地区。简单的社会在边缘化地区避难，那里的集约化是不可行的。简单和复杂的社会并存，被不断变化的边界所分隔。一波三折，复杂的社会扩展到边缘土地，然后撤退到核心土地。模拟的结果在质量上与史前和历史案例研究一致。该模型复制了从简单社会到更复杂社会的发展过程，并解释了为什么这种发展过程适得其反。