Abstract: Social exchange is one of the important factors affecting the mental health of the elderly. A large number of literatures have pointed out that positive exchanges support mental health, however, the adverse effects of negative exchanges and its psychological mechanisms remain to be further examined. Based on extant literature, the article reviews and summarizes the effect of negative exchange on mental health of the elderly from the following aspects: research status, relevant mechanisms, theoretical explanations, coping strategy, and future direction.
Firstly, this paper discusses the adverse influence of negative exchanges on mental health from three different dimensions: type, source and intensity. Specifically, some basic types of negative exchanges, such as social isolation, widowhood and divorce could damage the mental health of the elderly. The influence of negative exchanges from different sources on the mental health of the elderly is different. For example, the influence from spouse and children is stronger, while the influence from friends and other immediate family members is weaker. The long-term and high-intensity negative exchanges will have a sustained adverse impact on mental health.
Secondly, we review the mechanisms of effect of negative exchanges on mental health. Negative exchanges can not only directly affect mental health, but also indirectly affect mental health through other factors, such as individual perception of social exchanges, self-esteem and so on. In addition, we point out that gender, marital status and education can moderate the relationship between negative exchanges and mental health. Specifically, when negative exchanges occur within the family, women will suffer more than men; when outside the family, the psychological pressure of women will be lower than that of men. In the face of emotional setbacks, the elderly with a partner suffers more psychological trauma; when facing economic difficulties or social exclusion, the loneliness of the elderly without a partner is stronger. The level of education will weaken the negative link between negative exchanges and mental health, that is to say, individuals with higher level of education will be less affected when they encounter negative exchanges.
Thirdly, this article attempts to explain the relevant mechanisms of negative exchanges on mental health from four theoretical perspectives, and points out the differences in the explanation mechanism and application scope of these theories. Based on the socioemotional selectivity theory, negative exchanges could hinder the smooth realization of the emotional goals of the elderly, and then damage their mental health. This theory is mainly applicable to the elderly. According to the strength and vulnerability integration theory, negative exchanges can lead to continuous tension of physiological state and reduce the sense of well-being. This theory is applicable to high-intensity or continuous negative exchanges. In the light of the social exchange theory, the weak side in negative exchanges is relatively passive, which leads to lower self-esteem and poor mental health. This theory is applicable to the weak side in social exchanges. Through the theory of looking-glass self, the negative atmosphere in the process of negative exchanges will be internalized into the negative cognition of the individual, which will lead to the deterioration of mental health. Extant literatures pointed out that “forgiveness” and “cognitive distancing” may be effective strategies to alleviate the negative effects of negative exchanges.
Finally, the article points out limitations of extant researches and research direction in future. Although the above theories can explain the adverse effects of negative exchanges, their explanatory power remains to be verified, and special theories of negative exchanges have yet to be put forward. At the same time, it is necessary to find practical intervention means to reduce the harm of negative exchanges. Researchers also need to pay attention to the differences in the roles of negative exchanges in different situations, such as cultural background, online communication on the internet and exchanges nested in social networks.

Key words: social relationship, negative exchange, mental health, the elderly