Evolutionary Game Theory - Rock Scissors Paper Game

Rock Scissors Paper Game

An evolutionary game that actually turns out to be a children’s game is rock-paper-scissors. The game is simple – rock bests scissors (blunts it), scissors bests paper (cuts it), and paper bests rock (wraps it up). Anyone who has ever played this simple game knows that it is not sensible to have any favoured play – your opponent will soon notice this and switch to the winning counter-play. The best strategy (a Nash equilibrium) is to play a mixed random game with any of the three plays taken a third of the time. This, in EGT terms, is a mixed strategy. But many lifeforms are incapable of mixed behavior — they only exhibit one strategy (known as a “pure” strategy”). If the game is played only with the pure Rock, Scissor and Paper strategies the evolutionary game is dynamically unstable: Rock mutants can enter an all scissor population, but then – Paper mutants can take over an all Rock population, but then – Scissor mutants can take over an all Paper population – and on and on…. This is easily seen on the game payoff matrix, where if the paths of mutant invasion are noted, it can be seen that the mutant "invasion paths" form into a loop. This in triggers a cyclic invasion behaviour.

Read more about this topic:  Evolutionary Game Theory

Famous quotes containing the words rock, paper and/or game:

    Compare the history of the novel to that of rock ‘n’ roll. Both started out a minority taste, became a mass taste, and then splintered into several subgenres. Both have been the typical cultural expressions of classes and epochs. Both started out aggressively fighting for their share of attention, novels attacking the drama, the tract, and the poem, rock attacking jazz and pop and rolling over classical music.
    W. T. Lhamon, U.S. educator, critic. “Material Differences,” Deliberate Speed: The Origins of a Cultural Style in the American 1950s, Smithsonian (1990)

    There’s a long story, my friend. I never did like the idea of sitting on newspapers. I did it once and all the headlines came off on my white pants. On the level, it actually happened. Nobody bought a paper that day. They just followed me around over town and read the news off the seat of my pants.
    Robert Riskin (1897–1955)

    The chess-board is the world; the pieces are the phenomena of the universe; the rules of the game are what we call the laws of Nature. The player on the other side is hidden from us. We know that his play is always fair, just, and patient. But also we know, to our cost, that he never overlooks a mistake, or makes the smallest allowance for ignorance.
    Thomas Henry Huxley (1825–1895)