公平是人类社会有效运作的最为重要的准则之一。最后通牒游戏是探索人类公平相关决策的最为经典的范式，已被广泛地运用到探索公平相关决策的心理和神经机制的研究中。大量行为学研究表明，个体在遭遇不公平分配时，会牺牲自身利益对违反公平准则的个体做出惩罚,并且这种维护公平的行为几乎覆盖了世界的各个角落。神经科学方面的研究证明了这种“非理性”的行为过程涉及到情绪加工和认知控制脑区的参与。然后，个体的公平感作为一种特质与大脑活动之间存在一种怎样的关系仍然不得而知。本研究采用静息态功能磁共振成像技术（resting-state functional magnetic resonance imaging, fMRI）探索了大脑特定区域的全脑功能连接强度是否能够预测个体面对不公平分配时的行为表现。本研究分析了112名健康成人被试的行为和静息态脑影像数据。我们计算了各个体素的全脑功能连接强度（whole-brain functional connectivity strength, FCS）用于构建大脑自发神经活动的功能连接矩阵。结果表明，右侧前脑岛和右侧背外侧前额叶区域与全脑其他各个体素的功能连接强度与个体在最后通牒游戏中对不公平分配的接受率存在显著的正相关。随后，我们分析了感兴趣区与全脑其他体素的功能连接情况，进一步探索可以预测个体行为的功能连接。我们认为，这种个体行为与大脑自发神经活动的相关性可能是由基因或者外界环境所塑造形成。因此，本研究证明了大脑自发神经活动可以预测人类公平性相关的决策，为个体维持公平性的可能的神经机制提供了证据。

Fairness is one of the most important social norms in human society. As the classical paradigm of investigating fairness, the Ultimatum game has been used broadly to study about decision making related to fairness. According to the large sum of behavioral researches, people are willing to sacrifice personal benefits to punish the proposers who split the money unfairly between two people in the Ultimatum game, and such behavior aimed at maintain the equity of the society has been found almost every corner of the world. Studies of neural science have demonstrated that such kind of “irrational behavior” involves the activation of brain regions related to emotion processing and cognitive control. However, little is known about the relationship between the sense of fairness as a personal state and brain activity. Using resting-state functional magnetic resonance imaging (fMRI), the current research investigated whether the intrinsic functional connectivity (FC) of some specific brain regions can predict individuals’ responses to unfair offers. Both behavioral and neural imaging data from one hundred and twelve healthy participants were analyzed. The whole-brain functional connectivity strength (FCS) of each voxel of the brain was calculated to construct the brain’s spontaneous functional matrix. Correlation between each voxel’s functional connectivity strength and the participants’ acceptance rate of unfair offers was analyzed. Results revealed that the functional connectivity strength of right anterior insula and right dorsal lateral prefrontal cortex were positively related to the participants’ acceptance rate of unfair offers in the Ultimatum game. We later calculated the voxel-wise functional connectivity between those regions we are interested in and other voxels in the whole brain to detect those functional connectivities which can predict individuals’ behaviors related to the sense of fairness. We think that such correlation between human behaviors and the spontaneous brain activity might be driven by gene or environment. Thus the current research provides evidence that the spontaneous brain activity can predict human behavior related to fairness, which further supplements the possible neural mechanism of maintaining the norm of fairness in human society.