PS-I (Political Science-Identity) is an agent-based computer simulation platform originally developed to operationalize, refine, and test competing versions of constructivist identity theory. Based on an earlier prototype, the ABIR (Agent-Based Identity Repertoire) model, agents with repertoires of identities (or other potentialities) interact in localities of specifiable size and are influenced as well by cross-landscape values attached to particular identities. These values change over time, thereby simulating conditions in which individuals may express latent identities, or learn to use new identities, because of local pressures toward conformity and/or overall shifts in the relative attractiveness of presenting oneself as attached to one identity or another. Large batches of controlled virtual histories are used for comparative and statistical analysis. PS-I has been designed with two imperatives in mind: ease of deployment by users who know nothing of computer programming; and systematic correspondence between the algorithms for agent behavior and corroborated theoretical positions in political science and psychology. The non-technical user—the user with no programming skillsc—can PS-I, to build and execute sophisticated models of substantial academic and policy interest. PS-I thus differs very significantly from existing platforms complexions and governance patterns are now under development. The substantive problems of interest that triggered the development of ABIR and PS-I related to the crisis facing social scientists using constructivist theories of identity to understand patterns of mobilization, attachment, and conflict based on cultural, ethnic, religious, or other traits. Athough constructivist theory has been very successful in demonstrating the ineffectiveness of older “primordial†or “essentialist†notions of political identity, and in showing that identities are, within limits, fluid, tradeable, manipulable, and multiple, scholars employing these theories have been much less successful in studying the conditions under which and the limits within which collective identities can be stabilized, destabilized, created, or destroyed. The paper illustrates use of PS-I to study the dynamics of identity politics in a “typical†authoritarian Muslim Middle Eastern country subjected to globalizing pressures, religious mobilization, and conflict in culturally divided societies.
