13. ZambeziLand: A Canonical Theory and Agent-Based Model of Polity Cycling in the Zambezi Plateau, Southern Africa

The Zambezi plateau region in Southern Africa experienced the rise and fall of polities with different levels of inequality and complexity—known as cycling—for many centuries before the arrival of Europeans and the beginning of the region’s written history. We address the enduring research question of explaining politogenesis and polity cycling: the recurrent rise, fall, and abandonment of the earliest polities with monumental structures (such as massive stone-wall enclosures) called zimbabwes, built between ca. 1200 and 1450 CE. The agent-based model (ABM) presented here, called ZambeziLand, supports an explanation based on the Canonical Theory. In this theory, a succession of opportunities (situational changes) to engage in collective action by a community strengthens or weakens the complexity of the polity. The main finding from the ZambeziLand ABM simulation is that individual micro-level dynamics, driven by leadership and sentiments of loyalty to the community, can generate collective, macro-level behaviors observed in the archaeological record of the Zambezi Plateau.