Excess of Social Behavior Reduces the Capacity to Respond to Perturbations

Social interaction increases significantly the performance of a wide range of cooperative systems. However, evidence that natural swarms limit the number of social connections suggests potentially detrimental consequences of excessive social activity. Using a canonical model of collective motion, we find that the responsiveness of a swarm to local perturbations is reduced when the social interaction exceeds a certain threshold. We uncover a similar effect for two distinct collective decision-making models of distributed consensus operating over a range of static networks. While increasing the amount of interaction always increases the capacity of these systems to adapt to slow changes, an excess of social behavior can hinder the swiftness of their response to fast perturbations. These results have far-reaching implications for the design of artificial swarms or interaction networks.