公正世界信念对第三方惩罚的影响:来自ERP的证据

The Influence of Belief in A Just World on Third-Party Punishment:An ERP Study

采用事件相关电位技术(ERP)考察公正世界信念对第三方惩罚的影响。行为结果显示,高公正世界信念个体的第三方惩罚显著多于低公正世界信念个体,低公正世界信念个体在高不公正提议下的第三方惩罚显著增加;ERP结果显示,高公正世界信念个体比低公正世界信念个体诱发了更大的MFN波幅和更小的P300波幅,且高公正世界信念个体的MFN波幅在高、低不公正提议下没有差异,低公正世界信念个体在高不公正提议下的MFN波幅明显更大。这说明高公正世界信念个体更愿意做出第三方惩罚,且惩罚行为更多基于自身对于公正结果的预期,较少受到提议公正性的影响;而低公正世界信念个体的第三方惩罚会随提议不公正性的提高而增加。

Third-party punishment refers to the phenomenon that individuals sacrifice their own interests to punish the violators when the violation has nothing to do with their own interests(Fehr&Fischbacher,2004).Although third-party punishment is encouraged as a typical altruistic behavior,it is not common in the real world.On the contrary,when facing the victims of injustice in real life,people tend to treat them with indifference and seldom carry out third-party punishment.Lerner(1977)put forward the belief in a just world theory to explain these phenomena.Belief in a just world means that people need to believe that the world they live in is a just and orderly world,in which people get what they deserve.The significant individual difference of belief in a just world may lead to different behavioral responses to an unfair event.However,relatively few studies have explored the impact of belief in a just world on third-party punishment from the perspective of individual differences.This study will explore the impact of belief in the just world on third-party punishment.In addition,MFN and P300 are the two most common components in the ERP study of third-party punishment.So far,the neural mechanisms of justice and third-party punishment have been studied.Belief in a just world,as a subjective cognition of justice,is still lack of research on the neural mechanism of third-party punishment.Based on this,it is necessary to study the neural mechanism of belief in a just world that affects third-party punishment.In our study,the Personal Belief in a Just World Scale was used to test 83 college students.After excluding invalid data,the score results were ranked from high to low.The participants with the highest score of 27%were regarded as the group with high belief in a just world,while the participants with the lowest score of 27%were regarded as the group with low belief in a just world.Finally,there were 36 participants,18 of whom were in the high belief in a just world group and 18 of whom were in the low belief in a just world group.We administered a modified version of the third-party punishment task,in which participants made a choice between changing or not changing.This study recorded and analyzed the differences of ERP components in third-party punishment task to explore the neural mechanism of the impact of belief in a just world on the third-party punishment.The behavioral results showed that the third-party punishment of individuals with high belief in a just world is significantly higher than that of individuals with low belief in a just world,and the third-party punishment of individuals with high belief in a just world has no difference under high and low injustice proposal,while the third-party punishment of individuals with low belief in a just world is significantly higher under injustice proposal.The ERP results showed that individuals with high belief in a just world induced larger MFN amplitude and smaller P300 amplitude than individuals with low belief in a just world,and there is no difference in the MFN amplitude of individuals with high belief in a just world under high and low injustice proposal,while the MFN amplitude of individuals with low belief in a just world under high injustice proposal is significantly larger.In conclusion,the present study found that individuals with a high belief in a just world are more willing to perform third-party punishment,and the punishment behavior is more based on their own expectations of fair outcomes and less affected by proposed justice.Third-party punishment of individuals with a low belief in a just world will increase as the proposed injustice increases.