Social information use and the evolution of unresponsiveness in collective systems

Torney, C. J. , Lorenzi, T., Couzin, I. D. and Levin, S. A. (2015) Social information use and the evolution of unresponsiveness in collective systems. Journal of the Royal Society: Interface, 12(103), (doi:10.1098/rsif.2014.0893) (PMID:25519991) (PMCID:PMC4305405)

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Animal groups in nature often display an enhanced collective information-processing capacity. It has been speculated that natural selection will tune this response to be optimal, ensuring that the group is reactive while also being robust to noise. Here, we show that this is unlikely to be the case. By using a simple model of decision-making in a dynamic environment, we find that when individuals behave rationally and are subject to selection based on their accuracy, optimality of collective decision-making is not attained. Instead, individuals overly rely on social information and evolve to be too readily influenced by their neighbours. This is due to a classic evolutionary conflict between individual and collective interest. The result is a sub-optimal system that is poised on the cusp of total unresponsiveness. Individuals in the evolved group exhibit delayed reactions to changes in the environment, before responding with rapid, socially reinforced transitions, reminiscent of familiar human and animal social systems (markets, stampedes, fashions, etc.). Our results demonstrate that behaviour of this type may not be pathological, but instead could represent an evolutionary attractor for such collective systems.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Torney, Dr Colin
Authors: Torney, C. J., Lorenzi, T., Couzin, I. D., and Levin, S. A.
College/School:College of Science and Engineering > School of Mathematics and Statistics > Mathematics
Journal Name:Journal of the Royal Society: Interface
Publisher:The Royal Society
ISSN (Online):1742-5662
Published Online:17 December 2014

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