Properties of 2×2 game based on genetic algorithm

Evolutionary games are widely studied in the fields of biology, physics, sociology, economics and informatics. People´s interests focus on how to explain cooperation emerged in a population that individuals are selfish. Many researches reveal that some mechanisms contribute to the cooperation such that network structure, memory device and so on. This paper gives a new illustration to the phenomenon: inheritance. A scare-free network is build and agents locate on the nodes to simulate individuals in population. Each agent has two devices: memory and chromosome. The memory can remember the game history with its´ neighbors. The chromosome is constructed by genes (`0´ or `1´), and the genes mean cooperation or defection to a particular history. In a generation, every agent games with its neighbors repeatedly; its strategy (cooperation or defection) is decided by game history and chromosome. Then agents evolved to next generation by chromosome´s crossover and mutation with their neighbors who get high payoffs in games. We show the cooperation ratio distribution in the 2×2 game model and some characteristic genes and frequently used genes emerges after generations. These findings give new perspectives to the illustration of cooperation behavior in biological group and society.