The Influence Of Theory Of Mind On Inequity Aversion

In the process of evolution,human beings developed a tendency to reject unfair distribution,that is,inequity aversion(IA).In an unfair situation,when an individual holds the advantage,he will feel the advantage IA.In contrast,when an individual holds the disadvantage,he will feel the disadvantage IA.Numerous studies have shown that IA requires the participation of several kinds of social emotion and social cognitive functions.As one of the basic social cognitive functions,theory of mind(ToM)which refers to the ability or process of understanding others' cognition and emotions,therefore,may be involved in these two kinds of AI.Through two studies,the article tried to explore the relationship between ToM and AI among college students.Study 1 aimed at obtaining evidence of correlation explored the relationship between ToM tendency and AI,as well as the role of guilty traits in it.While the second study attempted to provide causal evidence that explains whether the process of ToM affects AI,through altering the neural activity of right temporo-parietal junction(rTPJ),as one of the key brain regions of the ToM.Through a large sample survey(N = 2626),study 1 measured ToM tendency by using the perspective taking scale,a subscale of Interpersonal Reactive Index Scale,and measured the guilty traits by using the Guilt and Shame Proneness Scale.The advantage and disadvantage IA were measured by a new version of dictator game paradigm,in which participant must choose one of two allocation schemes.Revealed by the result of the correlation analysis,ToM tendency,guilty traits and advantage IA were positively correlated with each other.In addition,the result of mediation analysis showed that guilty traits partially mediated the effect of ToM tendency on advantage IA.For the disadvantage IA,however,the above relationship has not been found.After that,the participants were divided into three groups of high,medium and low ToM tendency according to the score of perspective taking scale.The results showedthat there were significant differences in the advantage IA of the three groups.The advantage IA of high ToM tendency group was the highest,while the low group was the lowest.disadvantage IA among three groups also showed a similar trend.Study 2 used high-definition transcranial direct current stimulation(HD-tDCS)to manipulate the neural activity of rTPJ,and further explored the causal relationship between IA and the process of ToM.The anodal stimulation in HD-tDCS activates the neural activity of the target brain region,while the cathodal stimulation inhibits the neural activity of the target brain region.During the HD-tDCS stimulation,participants were asked to completed the dictator game with two forced selection.At the end of the experiment,the participants reported the degree of consideration of peer interest,personal interest,collective interest and the tendency to avoid guilty during forced selection.The results revealed that compared with the anodal stimulation group,the cathodal stimulation group had significantly lower advantage and disadvantage IA,which means that compared with activating rTPJ,inhibiting the activity of rTPJ reduces two kinds of IA.The results of subjective reports indicated that the difference of peer interest consideration among the three groups was also significant,as the score of the anodal stimulation group was significantly higher than the cathodal stimulation group.Correlation analysis suggested that the degree of consideration of peer interest and the tendency to avoid guilty are significantly positively correlated with advantage IA,while the degree of consideration of personal interest are significantly negatively correlated with advantage IA;And the degree of considering personal interest is significantly negatively correlated with disadvantage IA.The results of two studies,from correlation to causality,jointly depicted the relationship between ToM and two kinds of IA: ToM is an important basic function of IA,as low ToM tendency or ability will result in low IA,especially for the advantage IA.