The Effects Of Personality And Fnendliness On Cooperation Based On Evolutionary Game Theory

Recently, the theory of complex networks provides a convenient framework forstudying game relations among multi-player. Evolutionary game theory based oncomplex networks proposes a new method to investigate the evolution of cooperation inpopulation consists of selfish individuals. According to Darwinism, selfish behaviorscan get more rewards during fierce competition. However, natural selection makes thecooperation behaviors become popular in nature, this apparently contradicts Darwinism.In this thesis, based on the evolutionary game theory, some mechanisms that promotethe emergence and maintenance of cooperation are proposed.(1)This thesis develops a Prisoner’s Dilemma game model on static network basedon friendliness and personality. Each individual with different personality adjusts itsfriendliness to its neighbors by considering its neighbors’ strategies. After that, eachindividual selects its neighbors and updates its strategy on the basis of friendliness. Thesimulations show that this indirect reciprocity which based on friendliness andpersonality reinforces the relations between cooperators. Thus, the cooperative clustersare enhanced. Consequently, the cooperative behavior can persist at a high level over awide range of the temptation to defect.(2)The thesis proposes an evolutionary game model in which individuals can adjusttheir partnerships based on friendliness and personality. In this model, individuals canadjust their partnerships by their friendliness to their neighbors and the differencebetween individuals’personality. The simulations show that the existence of friendlinesscan promote cooperation. However, only at a low level temptation to defect, theexistence of friendliness can promote cooperative behavior. Furthermore, in the progressof evolution, the individuals who always cooperate can transform into hubs.Consequently, the heterogeneity of the networks increases. Moreover, an increasingtendency of switching partners is more likely to lead to a higher level of cooperation.However, the dense network will inhibit this cooperative behavior.