Voting has ended

Evolutionarily stable strategies

placing evolutionary thinking on a mathematical basis South East,

John Maynard Smith sits on a low chair while writing on a notepad. In the background are books, a window and some jars of liquid.
John Maynard Smith at work in his office, 1980s. Courtesy of the University of Sussex.

John Maynard Smith (1920-2004) of the University of Sussex, along with George R Price (1922-75), developed a new theory to explain why animals behave as they do when in conflict with others. Called ‘evolutionarily stable strategy’, it was published in the journal Nature in 1973. 

Working with Price’s ideas, Maynard Smith helped introduce game theory analysis to biology. Game theory is a mathematical method used to analyse how an actor - ‘player’ - should behave when there is incomplete information about what another actor - ‘opponent’ - is going to do. This can explain why, for example, it is uncommon for members of the same species to kill one another. Since no combatant can have complete information on the others’ capacities, the optimal course for both parties is to refrain from escalating the conflict. The result, the evolutionarily stable strategy, becomes a ritualised struggle - for instance among black grouse or ruffs - without bloodshed. 

This way to play games with a population became fundamental for thinking about evolution. In his Evolution and the Theory of Games (1982), Maynard Smith extended this to show that stable coalitions of individuals - for example lifelong pair bonds among swans and geese - may develop from a simple rule of thumb that boils down to ‘you scratch my back and I’ll scratch yours’.

Science Museum

South East
University of Sussex
Key Individuals
John Maynard Smith, George R Price,