AgentZero++: Modeling Fear-Based Behavior
Vrinda Malhotra, Jiaman Li, Nandini Pisupati
TL;DR
AgentZero++ extends Epstein's Agent_Zero by embedding affective learning, probabilistic risk estimation, and social contagion within a $50×50$ toroidal grid to model fear-based collective violence. Implemented in Python with the Mesa ABM framework, the model introduces eight cognitively grounded extensions (including age-based impulse control, memory, endogenous destructive radius, flight-or-fight dynamics, retaliatory damage, affect-cognition coupling, affective homophily, and multi-agent expansion) that enable modular experiments and visualization of micro-to-macro dynamics. Results show that small changes in memory length, affective alignment, and impulse control can trigger tipping points, escalation cycles, and localized retaliation via feedback loops, with flight behavior mitigating damage and longer memory sustaining activation. By explicitly modeling internal thresholds, identity-driven behavior, and adaptive networks, AgentZero++ provides a flexible platform for studying affective contagion, decentralized collective action, and resilience of social systems under emotional stress.
Abstract
We present AgentZero++, an agent-based model that integrates cognitive, emotional, and social mechanisms to simulate decentralized collective violence in spatially distributed systems. Building on Epstein's Agent\_Zero framework, we extend the original model with eight behavioral enhancements: age-based impulse control; memory-based risk estimation; affect-cognition coupling; endogenous destructive radius; fight-or-flight dynamics; affective homophily; retaliatory damage; and multi-agent coordination. These additions allow agents to adapt based on internal states, previous experiences, and social feedback, producing emergent dynamics such as protest asymmetries, escalation cycles, and localized retaliation. Implemented in Python using the Mesa ABM framework, AgentZero++ enables modular experimentation and visualization of how micro-level cognitive heterogeneity shapes macro-level conflict patterns. Our results highlight how small variations in memory, reactivity, and affective alignment can amplify or dampen unrest through feedback loops. By explicitly modeling emotional thresholds, identity-driven behavior, and adaptive networks, this work contributes a flexible and extensible platform for analyzing affective contagion and psychologically grounded collective action.
