Identification with all humanity reduces the ratio of moral differential circle

摘要: Identification with all humanity (IWAH) has emerged as a popular conceptualization essential for addressing global issues. This construct is generally considered both a stable individual characteristic and a moral concept. However, few studies have examined the influence of IWAH on moral psychological structure. Here, we propose an index of moral differentiation ratio based on the Moral Expansiveness Scale and investigate how IWAH affects this ratio, along with the cross-cultural universality and specificity of this relationship. Study 1 (N = 306) demonstrated a negative relationship between IWAH and the moral differential ratio using a questionnaire. Study 2 employed an imaginative priming paradigm to verify the effect of IWAH on reducing individuals’ moral differential ratio (N = 225). Furthermore, Study 3 recruited American participants (N = 256) and combined the data with Study 1, revealing that the effect of IWAH on reducing the moral differential ratio was weaker among Chinese participants compared to Western participants. This research introduces the novel concept of the moral differentiation ratio, which captures the variability of individual moral concern towards different entities. The findings highlight the importance of considering cultural variations when promoting global cooperation through appeals to IWAH.