Because human nature tends to sympathize and morality, it has a sense of responsibility to pursue moral goals [25] [26]. We more or less, or occasionally have some immoral behavior, which will harm our moral self-image. However, when we engage in immoral behavior, we still feel that we are a moral individual. Moral self licensing is used to explain this phenomenon, pointing out that the sense of security of self-image increases the possibility of our participation in immoral behavior. When our moral self-image is threatened, we can gain self-confidence from past moral behaviors. The more confident we are, the less we worry about future behavior. In fact, this increases the possibility of human participation in immoral behavior [27] [28]. Monin and Miller studied the effect of moral self permission, and found that when participants obtained a certificate proving that they were unbiased, although the audience did not know that they had a certificate, they were still more willing to express politically incorrect opinions [27].
