Minority-Triggered Reorientations Yield Macroscopic Cascades and Enhanced Responsiveness in Swarms

TL;DR

This paper introduces a biologically plausible minority-triggered reorientation mechanism in swarm models, which produces macroscopic cascades and enhances collective responsiveness, explaining rapid information spread in animal groups.

Contribution

It presents a novel reorientation rule that generates scale-free cascades and improves responsiveness in flocking models, bridging biological plausibility with macroscopic collective behavior.

Findings

Heavy-tailed cascades of reorientations observed

Enhanced responsiveness without losing cohesion

Mechanism explains rapid information spread in groups

Abstract

Collective motion in animals and cells often exhibits rapid reorientations and scale-free velocity correlations. This allows information to spread rapidly through the group, allowing an adequate collective response to environmental changes and threats such as predators. To explain this phenomenon, we introduce a simple, biologically plausible mechanism: a minority-triggered reorientation rule. When local order is high, agents sometimes follow a strongly deviating neighbor instead of the majority. This rule qualitatively changes the macroscopic system behavior compared to traditional flocking models, as it generates heavy-tailed cascades of reorientations over broad parameter ranges. Our mechanism preserves cohesion while markedly enhancing collective responsiveness because localized directional cues elicit amplified group-level reorientation. Our results provide a parsimonious, biologically interpretable route to critical-like fluctuations and high responsiveness during flocking.