Is morality hardwired into the brain? The recent advances and prospects of cognitive neural mechanism researches of morality

Abstract

“Is morality hardwired into the brain” is a major problem that have long puzzled philosophers. Since Piaget and Kohlberg, morality gradually comes into the view of psychological research. In the 21st century, morality has become a new growing point of cognitive neuroscience research and moral cognitive neuroscience has emerged. Current moral cognitive neuroscience studies give a preliminary answer to the above puzzle. These studies focus on three aspects: the brain mechanism of moral judgment, the brain mechanism of moral emotion and the integrative brain mechanism models of morality. Moral judgement is a process of individuals’ moral evaluation of their own or others’ behavior according moral principles which is the interaction of cognition and emotion. Therefore, the brain regions of moral judgment not only consist of some brain areas related to cognitive process which include DLPFC, ATL and TPJ, but also involve some brain areas related to emotional process which include VMPFC, OFC, ACC and amygdala. Moral emotions are some complex emotions which arise from moral evaluation of one’s own of others’ behavior and affect the occurrence and change of moral behavior, such as empathy, guilt and admiration, etc. Many studies show that the main brain areas of cognitive empathy are VMPFC and TPJ, and the core brain areas of emotional empathy include ACC, AI and mirror-neuron system. On the one hand, positive empathy has some same brain mechanism with negative empathy, for instance, both of them can activate left AI. On the other hand, there are certain cognitive neuroscience difference between positive empathy and negative empathy. Positive empathy activates the brain reward system, but negative empathy activate the right AI. The brain areas of guilt are mainly in VMPFC, precuneus, TP, ACC and insula. Admiration for virtue can activate posterior PMC, ACC, anterior insula, hypothalamus and folia cerebelli. The main integrative brain mechanism models of morality are dual-process theory of moral judgment, Event-Feature-Emotion Complexes, Triune Brain Theory, and brain mechanism models of cooperation and altruistic punishment. In the point view of dual-process theory of moral judgment, moral judgement which is related to explicit cognitive reasoning process and implicit emotional motivation process needs comprehensive function of VMPFC, PCC, precuneus, amygdala, ACC, inferior parietal cortex and DLPFC. The main components of Event-Feature-Emotion Complexes are structured event knowledge, social perception and functional features, and central motive states. According to Triune Brain Theory, the neural bases of safety ethic, engagement ethic and imagination ethic are reptilian brain, paleomammalian brain and eomammalian brain respectively. Cooperative decision-making is based on the interaction of reward system, cognitive control system and social cognition system. The brain mechanism model of altruistic punishment includes three system: reward, cognition and emotional regulation. Future researches should integrate the existing research results, improve ecological validity gradually, use many methods synthetically, and rich and expand research perspectives.