关键词: 经济不平等, 社会凝聚力, 人际关系, 群际关系, 社会规范

Abstract: Economic inequality not only adversely affects people’s physical and mental health, but is also linked to various social issues, including reduced civic engagement, increased social conflict, and higher crime rates. The underlying mechanism behind these negative outcomes in societies with high inequality is often attributed to reduced social cohesion. It is plausible that in less cohesive societies, individuals are less likely to participate in communal activities, advocate for policies that benefit the broader community, and provide material and emotional support to others. Therefore, this paper adopts a social psychological perspective to explore how economic inequality weakens social cohesion through a range of cognitive and motivational factors that arise from the interpersonal, intergroup, and normative processes.
Regarding the interpersonal level, we argue that high levels of inequality undermine social connections through processes of social comparison and status competition. Economic inequality, characterized by disparities in income or wealth, alters the framework and outcomes of social comparison. Specifically, individuals typically prefer upward comparison rather than downward comparison in terms of socioeconomic status. Consequently, people in more unequal contexts face a higher standard of comparison, and thus experience heightened status anxiety and desire for wealth in societies with high inequality. Given people generally view the gain and loss of wealth as the result of a zero-sum game, individuals in societies with high inequality are more likely to develop a competitive rather than cooperative mindset, thus eroding interpersonal trust and bonds.
At the intergroup level, we argue that economic inequality increases the likelihood of social conflict between different socioeconomic groups through processes of group categorization and social identity. Economic inequality accentuates wealth disparities between the rich and the poor, leading to a heightened tendency to perceive and categorize social groups on the basis of wealth. Such categorization diminishes the sense of shared destiny and fosters alienation and hostility between groups. At the same time, in societies with high levels of inequality, the affluent group becomes an advantaged group identity, which drives people’s desire to have more wealth for a positive group identity. How wealth is obtained or maintained depends on perceptions of social mobility and justice, thereby influencing intergroup dynamics. For instance, low levels of social mobility and injustice lead to the adoption of social competition strategies, resulting in increased social conflict and chaos.
Finally, at the level of social norms, economic inequality increases people's expectations of a competitive social climate through normative perceptions, which leads to less trust in social interactions. In societies with higher economic inequality, social strategies based on dominance and competition are more adaptive. Thus, people view economic inequality as an environmental feature and make inferences about the norms in that environment. Specifically, societies with high inequality are expected to foster a more competitive climate, which in turn increases individuals' social vigilance toward others.
Based on existing knowledge, several issues remain underexplored and warrant further attention. First, the three processes summarized in this paper have been studied relatively independently in existing empirical research. Future research should integrate these processes and explore their interactions at different psychological levels to better understand how economic inequality weakens social cohesion. Second, the conditions under which people adopt individual mobility or social competition strategies remain inadequately explored. The choice of strategy may depend on the level of economic inequality and on individuals' cognitions and beliefs, such as system-justifying ideologies and meritocratic beliefs. Third, while prior studies have highlighted that economic inequality increases competitive behaviors, recent studies have produced inconsistent results, with some finding that economic inequality enhances people's willingness to engage in instrumental cooperation. Thus, future studies should not solely focus on competition and cooperation but should thoroughly investigate the effects of economic inequality on various other facets of social relationships. Fourth, although existing empirical studies have examined the relationship between economic inequality and several indicators of social cohesion, there are still some key indicators (e.g., willingness to follow social rules and acceptance of external groups) that have not received attention. Future research can more comprehensively examine the relationship between economic inequality and social cohesion based on the three processes of interpersonal, intergroup, and normative. Finally, future studies should consider the potential role of culture in the impact of economic inequality on social cohesion. In contrast to Western societies, East Asian cultures place greater emphasis on social hierarchy, and individuals within these cultures tend to hold stronger beliefs in power distance. This heightened acceptance of inequality could significantly shape the dynamics of how economic inequality affects social relationships.

Key words: economic inequality, social cohesion, interpersonal relationship, intergroup relationship, social norm