Repeated and incontrovertible collective action failure leads to protester disengagement and radicalisation

Protest is ubiquitous in the 21st Century and the people who participate in such movements do so because they seek to bring about social change. However, social change takes time and involves repeated interactions between individual protesters, social movements and the authorities to whom they appeal for change. These complexities of time and scale have frustrated efforts to isolate the conditions that foster an enduring movement, on the one hand, and the adoption of more radical (unconventional, unacceptable) tactics on the other. Here, we present a novel, theoretically informed and empirically evidenced, agent-based model of collective action that provides a unified framework to address these dual challenges. We model ~10,000 iterations within a simulated society and show that where an authority is responsive, and protesters can (cognitively and/or socially) contest the failure of their movement, a moderate conventional movement prevails. Conversely, where an authority repeatedly and incontrovertibly fails the movement, the population disengages but becomes radicalised (latent radicalism). This latter finding, whereby the whole population is disengaged but prepared to use radical methods to bring about social change, likely reflects the febrile pre-cursor state to sudden, revolutionary change. Results highlight the potential for simulations to reveal emergent, as-yet under-theorized, phenomena.