The Impacts of Positive Psychology and Individualism on Mental Health Status of the Elderly in China: Evidence From Chinese General Social Survey Data


 Background

Many previous studies have proved that positive psychology can promote mental health. However, little is known about how and when it promotes mental health in older adults.
Methods

The data of this study were sourced from the 2017 wave of Chinese General Social Survey (CGSS), involving 1,537 older adults aged 60 and above. OLS regression model was used to explore the impact of positive psychology on mental health of the elderly. Moreover, stata 16.0 was used to measure the moderating effect of individualism on the relationship between positive psychology and mental health.
Results

After controlling for demographic characteristics, socio-economic status and lifestyle factors, the regression results suggest that positive psychology was associated with mental health (coefficient = 0.112, p < 0.01). In addition, the positive relationship was significantly stronger for people who were older, married, lived in urban areas, with higher education and higher subjective social class position, and higher exercise frequency. Moreover, the moderating effect analysis results suggest that individualism strengthened the relationship between positive psychology and mental health.
Conclusions

This study reveals that positive psychology has a positive effect on mental health among the elderly, and the positive health effect shows significant age, marital status, living areas, education background, social class position and physical exercise inequalities. Furthermore, this study also provides new evidence indicating that individualism positively moderates the relationship between positive psychology and mental health. Promoting positive psychology can be a promising way for China to promote psychological care for the elderly in the future.

development and the spiritual pillar of unity, encouragement, and support for social progress [8]. The connection between the Chinese dream and the American dream is the positive psychology behind the national dreams. The importance of positive psychology to China is not only the promotion of history, the inevitable requirement of development, the voice of the Chinese people, but also the responsibility of China's healthy aging.

Literature review
Compared with positive emotions, commitment, relationships and achievements, there were few studies on the impact of positive psychology on the mental health of the elderly. Like achievements, positive psychology is a promoting factor, which will make the elderly more resilient when facing di culties in life [9][10][11]. Scholars have explored the impact of positive psychology on mental health among people. The theoretical basis of positive psychology is Darwin's theory of evolution. In his theory of evolution, Darwin pointed out that human psychology is the result of long evolutionary history. Natural selection and sexual selection are the main evolutionary processes that produce these psychological mechanisms. The meaning of the selected psychological mechanism is to be conducive to human survival and reproduction. Human evolutionary choice makes human beings have positive nature, empathy, self-control, moral sense, and reason, like learning, love creation, good at imagination and willing to plan the future. It also makes human beings have love, a sense of responsibility, understand communication and cooperation, have the ability of aesthetic and image thinking, and improve their mental health status [12,13]. Furthermore, humans have one of the oldest nerve channels, called the vagus nerve. The vagus nerve governs most of the organs of the respiratory and digestive systems, as well as the feeling, movement, and gland secretion of the heart. The new research of positive psychology has found that the vagus nerve is related to prosocial behavior, morality, and positive experience of happiness [14][15][16]. Research on the elderly found that when people see noble and beautiful things, they will feel a positive force because of the opening of the vagus nerve [17]. Moreover, a study argued that when people are positive, their self-identity will be improved and they will be more willing to design and pursue life goals, so that their intellectual resources will be improved and their ability to solve problems, think about problems and create problems will be strengthened [18]. The study of Song et al. (2019) focused on the e cacy of psychological capital intervention (PCI) for depression from the perspective of positive psychology supported this conclusion [19]; the scholars agreed that positive psychology makes people produce positive emotions, including pride, calm, gratitude, satisfaction, interest, pleasure, hope, curiosity, and love. Positive emotion is an important ability that can help improve people's quality of life and happiness index. It is a valuable renewable resource. In addition, some studies summarized the moderating role of personal value between positive psychology and mental health [20,21].
In Chinese society, after economic reform in 1978, the erce competition of the free market economy to a large extent urged the individual atomized [22]. These individuals have lost the protection of the original planned economic unit system, and all social problems have been transformed into personal viability and let individuals bear these problems alone. In the 1980s, personal independence was once a liberation force admired by everyone, but now it has become a huge pressure that vulnerable individuals can't bear. After the mid-1990s, when the individualism ideology began to envelop the market, it also participated in the re-shaping of people, which made people equip with more independent consciousness [23]. Entering the 21st century, with the development of urbanization and the development of socialist market economy with Chinese characteristics, individualism has become an irreversible trend in Chinese society Individualism can positively or negatively regulate the relationship between positive psychology and mental health. On the one hand, individualism can play a negative regulatory role. Under the catalysis of individualism, due to the lack of responsibilities and obligations for the public interest, individuals have no sense of belonging to the community. Especially for people born in and after 1980s, economic reform has made them realize that personal interests had priority over collective interests, and they can't nd an organic connection with public life and public community, so they can't bear the corresponding responsibilities required by society, which may lead to their lack of positive psychology and reduce their mental health [24]. Besides, individualism may degenerate into more and more intense anxiety. The emergence of solipsistic individualism is related to the disappearance of certainty and security. When various communities acting as protectors are dissolved, people may lose their sense of security, and this will damage their mental health status [25]. On the other hand, individualism plays a different role for people born in 1960s and before. These people are the elderly in China. They experienced famine and poverty in the collectivist period. Individualism brings them hope that people can actively pursue life happiness. Economic reform in 1980s made them more aware that Individualism can play a positive role of initiative and participation in personal life and social interaction. This also means that individualism promotes people's own welfare [26]. In Chinese context, old people with individualism have a more positive attitude to face life challenges and have better resilience and mental health status in the transitional society [27].
Therefore, for the elderly in China, individualism is more likely to promote the relationship between positive psychology and mental health.
In summary, as fewer empirical studies have explored the impact of positive psychology on the mental health status of older adults in China, in the context of the rise of individualism. To ful ll this gap, this study aims to explore the relationship between positive psychology and mental health for the elderly in China, using the 2017 wave of Chinese General Social Survey (CGSS) data. The results of this study could shed light on future studies concerning the effect of positive psychology on mental health in transitional society.

Data Source
The data of this study were obtained from the 2017 wave of the Chinese General Social Survey (CGSS). CGSS data are freely available at http://cnsda.ruc.edu.cn/index.php?r=projects/view&id=94525591. CGSS is a nationally representative longitudinal survey of communities, households, and individuals in China. Since 2003, CGSS has conducted an annual survey on individuals in 125 counties (districts), 500 streets (townships and towns), 1,000 neighborhood (village) committees and 10,000 families in China. By regularly and systematically collecting data from Chinese people and all aspects of Chinese society, CGSS summarizes the long-term trend of social change. The data in the CGSS are de-identi ed. The actual sample size of this project in 2017 was 12,582. Given the fact that this study investigated the impact of positive psychology on mental health among older population, respondents under 60 were removed. After deleting cases with missing information, a total of 1,533 older adults aged 60 and above were included in this study.

Dependent Variable
In this study, subjective mental health indicators were used to represent mental health status of older adults [28]. For example, positive and negative sensory indicators of mental health are subjective indicators. Subjective indicators are not random imagination but based on statistics. The subjective mental health indicators we selected include positive indicators and negative indicators, which can re ect the health status from a holistic view. In CGSS, older adults were requested to indicate their degree of subjective happiness and depression frequency, respectively. The responses to the two questions range from 1 to 5, and a higher number suggests a higher degree of mental health status. This study then summed the responses to obtain a mental health score, which ranges from 2 to 10.

Independent Variable
Positive psychology mainly refers to a positive psychological attitude or state. It is a positive and stable psychological tendency for individuals to treat themselves, others, or things [29]. When encountering negative things, positive psychology can change people's perspective on problems, cultivate positive thinking skills, and change people's behavior mode [30]. In CGSS, respondents were asked about six related questions, to indicate their positive psychological attitude, including attitude for uncertainty and hope. Each question used a 5-point Likert scale. This study summed these responses to get a positive psychology score, and the total score of the ve questions is 6 to 30 points, with a higher score indicating more positive psychology attitude.

Moderating Variable
Individualism is a political, ethical, and social philosophy that emphasizes personal freedom, personal interests, and self-control [31]. In China, the most individualistic issue is fertility, because China has experienced a period of family planning, and at present, birth restrictions are being liberalized. In CGSS, older adults were asked about their liberal attitude towards the number of children. The response ranges from 1 to 5, with a higher number indicating higher degree of individualism.

Control Variables
Since socio-demographic characteristics and health-related lifestyle factors signi cantly impacted the mental health of the elderly [32,33]. To reduce the bias of omitted variables, three categories of control variables were used in this study. The rst type of control variable describes the demographic characteristics, including four variables: age, gender, marital status and living areas. The second type of control variables describes the socio-economic status, including three variables: education background, income, and subjective social class position. The third type of control variables focuses on health-related lifestyle factors, including four variables: internet use, friend interaction, gathering with relatives, and physical exercise. It worth mentioning that age is a continuous variable, gender is binary variable ("male"=1, "female"=0), marriage is a binary variable ("being in marriage"=1, "not in marriage"=0), living area is a binary variable ("urban"=1, "rural"=0), education background is a binary variable ("above junior high school"=1, "junior high school and below"=0), and income is a binary variable ("above 10,000 RMB per year"=1, "below 10,000 RMB per year"=0). Besides, subjective social class ranges from 1 to 10, with higher score indicating higher social class position. What's more, internet use, friend interaction, gathering with relatives and physical exercise all ranges from 1 to 5, with higher score indicating higher frequency.
Furthermore, before the empirical study, the method expansion factor was used to test the main variables. The results showed that the Variance Expansion Factor (VIF) value of independent variables, moderating variables, and control variables were far lower than the critical value of 10, which further suggested that there was no multicollinearity problem across these regression models.

Methodology
In accordance with the Grossman's analysis frame [34], this study constructs the following econometric model to analyze the impacts of positive psychology and individualism on mental health: Where i indicates the individual, Mental health i denotes the mental health score for the older adult i, β 0 refers to the intercept term, β 1 , β 2 and β 3 are the regression coe cients for positive psychology, individualism, and interaction item, respectively. In addition, CV i stands for the control variables, and ε i represents the error term.

Results
Characteristics of the study population Table 1 reports the characteristics of the study population. The mean value of mental health, positive psychology, individualism of respondents was 7.615, 21.205, and 2.675, respectively. Furthermore, most respondents were aged around 71.412, and more than half of them were women. Most respondents were married. Half of the respondents lived in urban areas. Most respondents positioned themselves as medium to lower class in society, and they received less than 9 years of education and had income less than 10,000 RMB. Moreover, seldom did the respondents use internet, interact with friends or relatives, or do physical exercise. Overall Regression Results Analysis Table 2 shows the overall regression results. The overall regression results suggest that mental health was associated with positive psychology (coe cient = 0.114, p < 0.01). This suggests positive psychology can alleviate mental health status among older adults. Furthermore, it was found that being older, married, living in urban areas, having more years of education, positioning in higher social class, and doing more physical exercise were signi cantly associated with higher mental health status. Moreover, the regression results also indicate that gender, income, internet use, friend interaction and gathering with relatives had no signi cant impact on mental health status of the elderly.

Regression Results In Different Subgroups
In this section, this study further examined whether the mental health bene t of positive psychology differs by living area and physical exercise. The reason why investigate living area and physical exercise is that age, marital status, and social class have long been proved associated with mental health status. However, fewer studies focused on the heterogeneity of living area and physical exercise, considering China's unique urban-rural differences and physical exercise has recently been promoted as a national strategy, this study chose living area and physical exercise to carry out further regression analysis. Table 3 illustrates the regression results by living area and physical exercise. The regression results reveal that positive psychology improved mental health for older adults lived in both urban areas (coe cient = 0.099, p < 0.01) and rural areas (coe cient = 0.125, p < 0.01). Moreover, there was no evidence to suggest that there was statistically signi cant different for urban and rural older adults. Furthermore, the mental health promoting impact of positive psychology was stronger for the elderly living in rural areas.  According to Table 3, the effect of positive psychology on mental health was at signi cant level for all physical exercise subgroups. However, the effect was the largest for older adults did physical exercise several times a month (coe cient = 0.196, p < 0.01). In addition, for older adults who exercise every day, the impact of positive psychology on mental health was the least (coe cient = 0,053, p < 0.05). This phenomenon indicates that medium level of physical exercise group achieved the best effect to improve mental health through positive psychology.

Moderating Mechanism Analysis
In this section, this study attempted to explore the moderating effect of individualism on the relationship linking positive psychology and mental health among the aged, and Table 4   Notes: ***p<0.01, **p<0.05, *p<0.10. Positive Psychology * Individualism means the interaction item of positive psychology and individualism.

Robustness Test
Changing the measurement method is one of the effective means for robustness test. This study replaces OLS regression with logit regression for robustness test. If the conclusions of the two models are basically the same, the conclusion is robust and reliable. Table 5 shows that after logit model was used to run regression analysis, the results were consistent with previous regression models, so the results are robust  Based on existing studies [35][36][37], this study contributes to an understanding of the impacts of positive psychology and individualism on mental health status and the comparison of urban-rural and physical exercise disparities: (1) This study not only investigated the effects of positive psychology on the mental health of the elderly, but also introduced individualism as a moderating variable to analyze the impact mechanism.
(2) Considering at present, most studies focus on intervention treatment through experimental method to explore the impact of positive psychology on mental health. This study uses questionnaire data to establish a measurement model for research. This is consistent with the conclusion con rmed by many studies, that is, positive psychology will enhance self-e cacy and personal resilience, and improve the level of mental health [38][39][40][41]. But the difference is that this study makes up for a research gap: what mechanism does positive psychology affect the mental health of the elderly? This study found that individualism plays an important regulatory role in it, promotes the positive impact of positive psychology on the mental health of the elderly.
More studies are recognizing that as a general attitude towards political, economic, social, and religious behavior, individualism includes high evaluation of personal self-con dence, personal private life and respect for individuals, opposition to authority and all kinds of domination over individuals, which can enhance positive psychology [42,43]. Moreover, one of the important symbols of modernity is the rise of individual and the emergence of individualism. Over the past 30 years of economic reform, great changes have taken place in the social culture of contemporary China. The concept of self-consciousness and individual rights has risen unprecedentedly. An individualistic society has come. 44 This also shows that individualism is credible as a moderating variable.
According to previous studies, positive psychology is a powerful health capital, which can urge people to actively face the di culties of life, have strong determination and courage to overcome di culties, create a better life and pursue happiness [45,46]. However, these studies did not realize the importance of individualism as an important cultural factor shaping the relationship between positive psychology and mental health. On the one hand, the individualistic cultural gene in western culture, especially the cultural concept of personality liberation and personal freedom promoted after the Renaissance and religious reform, is an internal force for the nal formation of an institutionalized market economic order in western modern society. It also promotes individuals to bear market risks, create a better life and strengthen positive psychology [47]. provide more concrete evidence. Secondly, in addition to the differences between urban and rural areas, there are also great regional differences in China; however, due to the unavailability of data, this study failed to control for reginal factors. Third, the evaluation of health-related lifestyle factors is extremely complex, and how to measure it comprehensively has not reached a uni ed consensus. Therefore, the selected variables re ecting lifestyle factors may be far from complete. has not been formed [50]. It is di cult to establish the collective positive psychology and improve mental health. On the other hand, with the development of the market economy, people have obtained unprecedented freedom in the private sphere and have a sense of personal rights. On the other hand, individuals were thrown out by various disintegrated communities, especially the elderly generation, have realized "self-centered", but they can't nd an organic connection with public life and public community [51,52]. Therefore, they may encounter di culties producing the positive psychology needed for mental health.
The purpose of this study is to show that for the elderly, individualism can promote the positive impact of positive psychology on mental health, but this individualism is not atomized individualism, but the consciousness of citizenship and individual rights under the proper protection of individual rights. This is also the reason why this study chose reproductive attitude as the representative variable of individualism. Because family planning once deeply restricted individuals' reproductive rights.

Conclusion
Through empirical analysis, this study drew the following conclusions: (1) Positive psychology could signi cantly increase the mental health of the elderly. In addition, by dividing samples into subgroups according to living area and physical exercise frequency, this study found that positive psychology had a signi cant impact on the mental health of both urban and rural elderly people at 1% signi cance level; this shows that the power of positive psychology can surpass the impact of the objective economic, cultural, and political gap caused by China's urban-rural dual structure on people and improve mental health.
Meanwhile, for people who exercise several times a month, the mental health bene t of positive psychology is the largest. (2) Individualism promotes the relationship between positive psychology and mental health damage.
The results suggest that positive psychology is signi cantly associated with a better mental health status for older Chinese residents, moderated by individualism, which is consistent with China's recent development of market economy, the improvement of the rule of law and the improvement of citizens' awareness of individual rights.
Abbreviations CGSS Chinese General Social Survey. Figure 1 The Moderating Effect of Individualism