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Group decision-making in animals

Abstract

Groups of animals often need to make communal decisions, for example about which activities to perform1, when to perform them2,3,4,5,6,7,8,9 and which direction to travel in1,6,7; however, little is known about how they do so10,11,12. Here, we model the fitness consequences of two possible decision-making mechanisms: ‘despotism’6,7,10 and ‘democracy’1,6,7,10. We show that under most conditions, the costs to subordinate group members, and to the group as a whole, are considerably higher for despotic than for democratic decisions. Even when the despot is the most experienced group member, it only pays other members to accept its decision when group size is small and the difference in information is large. Democratic decisions are more beneficial primarily because they tend to produce less extreme decisions, rather than because each individual has an influence on the decision per se. Our model suggests that democracy should be widespread and makes quantitative, testable predictions about group decision-making in non-humans.

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References

  1. Prins, H. H. T. Ecology and Behaviour of the African buffalo (Chapman & Hall, London, 1996)

    Book  Google Scholar 

  2. Cote, S. D., Schaefer, J. A. & Messier, F. Time budgets and synchrony in activity in muskoxen: the influence of sex, age and season. Can. J. Zool. 75, 1628–1635 (1997)

    Article  Google Scholar 

  3. Conradt, L. Could asynchrony in activity between the sexes cause inter-sexual social segregation in ruminants? Proc. Roy. Soc. B 265, 1359–1363 (1998)

    Article  CAS  Google Scholar 

  4. Ruckstuhl, K. E. To synchronise or not to synchronise: a dilemma for young bighorn males? Behaviour 136, 805–818 (1999)

    Article  Google Scholar 

  5. Stewart, K. J. & Harcourt, A. H. Gorillas vocalizations during rest periods—signals of impending departure. Behaviour 130, 29–40 (1994)

    Article  Google Scholar 

  6. Byrne, R. W. On the Move (eds Boinski, S. & Garber, P. A.) 491–518 (Univ. Chicago Press, Chicago, 2000)

    Google Scholar 

  7. Milton, K. On the Move (eds Boinski, S. & Garber, P. A.) 357–418 (Univ. Chicago Press, Chicago, 2000)

    Google Scholar 

  8. Poole, J. H., Payne, K., Langbauer, W. R. & Moss, C. J. The social contexts of some very low-frequency calls of African elephants. Behav. Ecol. Sociobiol. 22, 385–392 (1988)

    Article  Google Scholar 

  9. Black, J. M. Preflight signalling in swans—a mechanism for group cohesion and flock formation. Ethology 79, 143–157 (1988)

    Article  Google Scholar 

  10. Norton, G. W. Primate Ecology and Conservation (eds Else, J. G. & Lee, P. C.) 145–156 (Cambridge Univ. Press, Cambridge, 1986)

    Google Scholar 

  11. Stolba, A. Entscheidungsfindung in Verbaenden von Papio hamadryas, 77–80. Thesis, Univ. Zurich (1979)

    Google Scholar 

  12. Boinski, S. & Campbell, A. F. Use of trill vocalizations to coordinate troop movement among white-faced capuchins—a 2nd field-test. Behaviour 132, 875–901 (1995)

    Article  Google Scholar 

  13. Stephens, D. W. & Krebs, J. R. Foraging Theory (Princeton Univ. Press, Princeton, New Jersey, 1986)

    Google Scholar 

  14. Krebs, J. R. & Kacelnik, A. Behavioural Ecology: an Evolutionary Approach, 3rd edn (eds Krebs, J. R. & Davies, N. B.) 105–136 (Blackwell, Oxford, 1991)

    Google Scholar 

  15. Cuthill, I. C. & Houston, A. I. Behavioural Ecology: an Evolutionary Approach, 4th edn (eds Krebs, J. R. & Davies, N. B.) 97–120 (Blackwell, Oxford, 1997)

    Google Scholar 

  16. Seeley, T. D. & Buhrman, S. C. Group decision making in swarms of honey bees. Behav. Ecol. Sociobiol. 45, 19–31 (1999)

    Article  Google Scholar 

  17. Conradt, L. & Roper, T. J. Activity synchronization and social segregation: a model. Proc. Roy. Soc. B 267, 2213–2218 (2000)

    Article  CAS  Google Scholar 

  18. Decastro, J. M. & Decastro, E. S. Spontaneous meal patterns of humans—influence of the presence of other people. Am. J. Clin. Nutr. 50, 237–247 (1989)

    Article  CAS  Google Scholar 

  19. Gompper, M. E. Sociality and asociality in white-nosed coatis (Nasua narica): foraging costs and benefits. Behav. Ecol. 7, 254–263 (1996)

    Article  Google Scholar 

  20. Grundgesetz fuer die Bundesrepublik Deutschland (BGB1. I S.1-1822, 1949).

  21. Wagenknecht, E. Der Rothirsch (Ziemsen, Wittenberg Lutherstadt, Germany, 1980)

    Google Scholar 

  22. Clutton-Brock, T. H., Guinness, F. E. & Albon, S. D. Red Deer: Behaviour and Ecology of two Sexes (Univ. Chicago Press, Chicago, 1982)

    Google Scholar 

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Acknowledgements

We thank J. Soeding, D. Waxman and H. Kokko for comments on an earlier version of the model, and H. Prins and M. Manser for help with accessing references. L.C. was supported by a Royal Society University Research Fellowship.

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Correspondence to L. Conradt.

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Supplementary information

41586_2003_BFnature01294_MOESM1_ESM.doc

Supplementary Information: This file contains mathematical details of a model of decision-making in animals. The model predicts the fitness consequences of two types of decision-making mechanism: 'despotism', in which a single individual makes the decision, and 'democracy', in which the decision taken is that of a majority of group members. The decision being modelled is that of when to stop engaging in a particular activity ('activity synchronisation'). Information in the file relates to: (1) cases in which activity synchronisation costs do not increase linearly with the difference between a member's optimal activity duration and the group's realised activity duration; (2) cases in which activity synchronisation costs are not symmetrical (i.e., stopping an activity too early is more or less costly than stopping too late; and (3) the cost, to a despot, of coercing other group members into accepting its decision. (DOC 76 kb)

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Conradt, L., Roper, T. Group decision-making in animals. Nature 421, 155–158 (2003). https://doi.org/10.1038/nature01294

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