CAS Key Laboratory of Behavioral Science, Institute of Psychology, Beijing, China.
Department of Psychology, University of Chinese Academy of Sciences, Beijing, China.
Soc Cogn Affect Neurosci. 2019 May 31;14(5):539-548. doi: 10.1093/scan/nsz031.
Human beings often curb self-interest to develop and enforce social norms, such as fairness, as exemplified in the ultimatum game (UG). Inspired by the dual-system account for the responder's choice during the UG, we investigated whether the neural basis of psychological process induced by fairness is under genetic control using a twin fMRI study (62 monozygotic, 48 dizygotic; mean age: 19.32 ± 1.38 years). We found a moderate genetic contribution to the rejection rate of unfair proposals (24%-35%), independent of stake size or proposer type, during the UG. Using a voxel-level analysis, we found that genetic factors moderately contributed to unfairness-evoked activation in the bilateral anterior insula (AI), regions representing the intuition of fairness norm violations (mean heritability: left 37%, right 40%). No genetic contributions were found in regions related to deliberate, controlled processes in the UG. This study provides the first evidence that evoked brain activity by unfairness in the bilateral AI is influenced by genes and sheds light on the genetic basis of brain processes underlying costly punishment.
人类常常会抑制自身利益，以制定和执行社会规范，如公平。在最后通牒博弈（UG）中，人们可以看到这一点。受双系统理论启发，该理论解释了 UG 中回应者的选择过程，我们使用双胞胎 fMRI 研究（62 对同卵双胞胎，48 对异卵双胞胎；平均年龄：19.32±1.38 岁）来研究公平引起的心理过程的神经基础是否受遗传控制。我们发现，在 UG 中，人们对不公平提议的拒绝率存在中等程度的遗传影响（24%-35%），与赌注大小或提议者类型无关。使用体素水平分析，我们发现遗传因素对双侧前岛叶（AI）中不公平引发的激活有中等程度的贡献，这些区域代表了对公平规范违反的直觉（左侧 37%，右侧 40%）。在 UG 中与深思熟虑、受控过程相关的区域没有发现遗传贡献。这项研究首次提供了证据，证明双侧 AI 中不公平引起的大脑活动受到基因的影响，并揭示了大脑过程背后的遗传基础，即代价高昂的惩罚。
