Evolutionarily stable strategy

Evolutionarily stable strategy
Solution concept in game theory
Relationship
Subset ofNash equilibrium
Superset ofStochastically stable equilibrium, Stable Strong Nash equilibrium
Intersects withSubgame perfect equilibrium, Trembling hand perfect equilibrium, Perfect Bayesian equilibrium
Significance
Proposed byJohn Maynard Smith and George R. Price
Used forBiological modeling and Evolutionary game theory
ExampleHawk-dove

An evolutionarily stable strategy (ESS) is a strategy (or set of strategies) that is impermeable when adopted by a population in adaptation to a specific environment, that is to say it cannot be displaced by an alternative strategy (or set of strategies) which may be novel or initially rare. Introduced by John Maynard Smith and George R. Price in 1972/3,[1][2] it is an important concept in behavioural ecology, evolutionary psychology, mathematical game theory and economics, with applications in other fields such as anthropology, philosophy and political science.

In game-theoretical terms, an ESS is an equilibrium refinement of the Nash equilibrium, being a Nash equilibrium that is also "evolutionarily stable." Thus, once fixed in a population, natural selection alone is sufficient to prevent alternative (mutant) strategies from replacing it (although this does not preclude the possibility that a better strategy, or set of strategies, will emerge in response to selective pressures resulting from environmental change).

  1. ^ Maynard Smith, J. (1972). "Game Theory and The Evolution of Fighting". On Evolution. Edinburgh University Press. ISBN 0-85224-223-9.
  2. ^ Maynard Smith, J.; Price, G.R. (1973). "The logic of animal conflict". Nature. 246 (5427): 15–8. Bibcode:1973Natur.246...15S. doi:10.1038/246015a0.