The Influence Of Asymmetric Punishment On Cooperative Behavior

In nature or human society, cooperative behavior can be observed extensively in bothintra-species, inter-species and individuals in human society. And the cooperation isoften a kind of altruistic behavior, which violates the selfish or rational assumption.Many issues, including when individual will show the altruism cooperation orselflessness, when cooperation is characterized by rational or selfish paradox, areunsolved problems in sociology, economics and life science.In current researches, Adam Smith had tried to make clear cooperation viahypothesizes of rational man in the Wealth of Nations. Darwin had tried to make clearthe cooperation of animals via hypothesis of individual adaption. However, if weassume that individuals are selfish or rational, why altruism cooperation behavior stillexists widely in nature or human society? Hamilton (1964) suggested that cooperationcan be maintained through genetic similarity, which formed the kin selection theory.Robert Trivers (1971) explained the phenomenon of cooperation through reciprocityrelatedness theory which holds that cooperation can be maintained through benefitsexchange. However, Boyd and Lorberbaum (1987) argued that if there is anequilibrium in the cooperation, it will eventually collapse due to the diffusion ofspeculation individuals. In recent years, further theoretical research and experimentalobservations have proceeded to show that it is difficult to explain the cooperation ofmaintaining mechanism for speculative phenomenon of cooperation system by theexisting theory.The above theories are based on an assumption that partners interact symmetricallywith equal payoffs in a game of cooperation interaction. Whereas in fact, cooperativepartners are in an asymmetric interaction which has been empirically implied in morereal cooperation systems. What kind of impacts will the asymmetry has on thecooperation system? What’s the difference between individuals involved inasymmetric cooperation when they are choosing strategies? To solve these problemsis significant to the study of the mutually cooperation system both in theory and practicase.Based on the repeated prisoner’s dilemma game experiment, this paper firstintroduces asymmetry punishment, which is namely that if the players choose thepunishment strategy, the gains of two sides will be unequal. Based on the research ofDreber et al (2008) and Wu et al.(2009), who designed the three tactics of symmetricexperimental, symmetrical experiment (A0) and asymmetric experiment (E) aredesigned by adjusting the penalty coefficient of the three tactics of symmetricexperimental. Under this circumstance, the coefficient ratio is set to1:4in thesymmetrical experiment (A0) and to1:2and1:4in the asymmetric experiment (E1).And the coefficient ration of1:6and1:4are set in the asymmetric experiment (E2).Compared with the symmetry experimental results, the cooperation ratio of theasymmetry is20%which is lower than symmetric cooperation ratio31.5%, whichindicates that asymmetry groups tend to use fewer cooperation strategy. Theasymmetric cooperation ratio is68%which is higher than the symmetric cooperativeratio57.5%, which shows that asymmetric groups tend to use more co-operative. Theasymmetric penalty ratio is12%which exceeds the symmetric penalty ratio11%,which demonstrates that asymmetric groups tend to use more punishment strategy. Byemploying the Mann-Whitney U nonparametric test in analyzing the differences ofstrategy choices between the groups of symmetric and asymmetric, it can concludethat there are significant differences between groups of symmetric and asymmetric onthe use of cooperative and noncooperative strategies, but no significant differences onthe use of punishment strategy. At the same time, by modeling analysis ofexperimental data, it also can conclude that asymmetric groups tend to use fewercooperation strategy but more non-cooperative and punishment strategy than thesymmetric groups.