collective irrationality and positive feedback集体非理性和积极的反馈.pdfVIP

Collective Irrationality and Positive Feedback 1 1 2 1 Stamatios C. Nicolis *, Natalia Zabzina , Tanya Latty , David J. T. Sumpter 1 Mathematics Department, Uppsala University, Uppsala, Sweden, 2 School of Biological Sciences, University of Sydney, Sydney, New South Wales, Australia Abstract Recent experiments on ants and slime moulds have assessed the degree to which they make rational decisions when presented with a number of alternative food sources or shelter. Ants and slime moulds are just two examples of a wide range of species and biological processes that use positive feedback mechanisms to reach decisions. Here we use a generic, experimentally validated model of positive feedback between group members to show that the probability of taking the best of n options depends crucially on the strength of feedback. We show how the probability of choosing the best option can be maximized by applying an optimal feedback strength. Importantly, this optimal value depends on the number of options, so that when we change the number of options the preference of the group changes, producing apparent ‘‘irrationalities’’. We thus reinterpret the idea that collectives show rational or irrational preferences as being a necessary consequence of the use of positive feedback. We argue that positive feedback is a heuristic which often produces fast and accurate group decision-making, but is always susceptible to apparent irrationality when studied under particular experimental conditions. Citation: Nicolis SC, Zabzina N, Latty T, Sumpter DJT (2011) Collective Irrationality and Positive Feedback. PLoS ONE 6(4): e18901. doi:10.1371/journal. pone.0018901 Editor: Yamir Moreno, University of Zaragoza, Spai