The interaction trade-off: from incoherence to rigidity. The interaction trade-off in drone swarms, and its relevance to social learning. With too little interaction (left), useful discoveries remain confined to individual drones and the swarm fails to benefit collectively. With too much interaction (right), the swarm converges rapidly but becomes rigid: a single erroneous cue can propagate to all members and dominate collective behaviour. The design challenge is to operate in the intermediate regime (centre), where information spreads efficiently enough to support effective coordination while preserving the autonomy and diversity that allow the swarm to remain robust under changing conditions.