Quorum responses and consensus decision making

David J T Sumpter, Stephen Pratt

Research output: Contribution to journalArticle

219 Scopus citations

Abstract

Animal groups are said to make consensus decisions when group members come to agree on the same option. Consensus decisions are taxonomically widespread and potentially offer three key benefits: maintenance of group cohesion, enhancement of decision accuracy compared with lone individuals and improvement in decision speed. In the absence of centralized control, arriving at a consensus depends on local interactions in which each individual's likelihood of choosing an option increases with the number of others already committed to that option. The resulting positive feedback can effectively direct most or all group members to the best available choice. In this paper, we examine the functional form of the individual response to others' behaviour that lies at the heart of this process. We review recent theoretical and empirical work on consensus decisions, and we develop a simple mathematical model to show the central importance to speedy and accurate decisions of quorum responses, in which an animal's probability of exhibiting a behaviour is a sharply nonlinear function of the number of other individuals already performing this behaviour. We argue that systems relying on such quorum rules can achieve cohesive choice of the best option while also permitting adaptive tuning of the trade-off between decision speed and accuracy.

Original languageEnglish (US)
Pages (from-to)743-753
Number of pages11
JournalPhilosophical Transactions of the Royal Society B: Biological Sciences
Volume364
Issue number1518
DOIs
StatePublished - Mar 27 2009

Keywords

  • Collective animal behaviour
  • Condorcet's theorem
  • Decision making
  • Quorum responses
  • Social insect migration

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)

Fingerprint Dive into the research topics of 'Quorum responses and consensus decision making'. Together they form a unique fingerprint.

  • Cite this