The Health China Initiative aims at narrowing the gap in basic healthcare services between urban and rural areas, regions, and communities, to achieve universal health coverage and social equity. The awareness of healthy life and family health (FH) management has been enhanced in recent years. The family lays the foundation for individual growth and sustainable development (1, 2), which exerts an unparalleled influence and resource for health maintenance and disease prevention (3, 4), especially during the post-coronavirus disease 2019 (COVID-19) era.

The hukou system was first devised in 1955 and propagated in 1958 as a measure of social control to restrict rural populations from access to state-allocated products, welfare, and rights. Based on the place of birth and lineage (i.e., mother's hukou type), each person is assigned a hukou type [either agricultural (rural) hukou or non-agricultural (urban) hukou] (5). Because the hukou system strictly confined people to the land they were born for a few decades, a de jure rural-urban division has been created (6). Due to the hukou system, there are distinct differences in geographical environment, welfare resources, behavioral habits, and cultural values between urban and rural China (7–10), which may translate into inequalities in the economic status, educational opportunities, employment and health outcomes (11–13). Education—perhaps the most salient modifiable social determinant and an upstream cause of health, is a powerful means of reducing socioeconomic and political disadvantages, to achieve upward mobility (14). However, the dual social structure causes disparities in the acquisition and utilization of educational resources between urban and rural residents (15–17). For the post-90s generation, the probability of urban students attaining higher education is 90% higher than that of rural students (65.12 vs. 34.41%) (18). Thus, education can also reproduce social class and health inequality. Poor education in rural areas can directly reduce the happiness perception of rural residents and negatively impact their happiness perception through income and social class perception gap (19). In this case, clarifying the nexus and mechanism between education and health is critical to avoid the unintended consequence of aggravating class solidification, which is beneficial to urban-rural integrated development.

Previous research has demonstrated a significant relationship between educational achievement and multiple health consequences, including mortality, self-rated health status, morbidity using objective health measures such as blood pressure, body mass index, hypertension, and chronic disease, and health-related behaviors such as smoking and drinking (20–22). However, so far, there is no consensus on the relationship between education and health. Some studies have reported a positive effect (23, 24), while others have reported no or even negative effects (25–27). The health benefits of education may vary among people with different socioeconomic statuses in different stages of education (28, 29), and a non-linear association should exist between education and health. Whilst numerous studies have explored individuals' health—focusing on physiological and behavioral factors—family, as a systematical unit to develop multifaceted material, psychological, emotional, social, and cultural capital for health, has attracted less attention (30). Moreover, the social context in which education and health processes are embedded has been ignored, which may have a limited impact on addressing disparities (31). From the lens of structuralism (32), the economic position and living conditions determined by the social structure can cause health inequalities (33). Nowadays, topics such as “small-town swot,” “impoverished families can hardly nurture rich sons,” and “schooling is useless” are heatedly debated. Therefore, it is necessary to explore the health benefits of education in China's unique dual social context. The present study examines the impact of education on FH for urban and rural residents, which may provide a panoramic view for policymakers, educators, and health practitioners to conduct interventions aimed at specific populations to reduce social inequality and promote common prosperity.

The family forms a the basic foundation for the individual and community health, as well as the basic unit of health care, disease prevention, and health promotion in the twenty-first century (34). Families are biologically, legally, or emotionally linked groupings, and health can “spread” through familial bonds. According to the family system theory, family members are interrelated, and individuals' health outcomes are determined by their family members (35).

Education can generate health externalities for individuals and their families through economic, health-behavior, and social-psychological paths (36) to preserve family wellbeing inter- and trans-generationally. Highly-educated people usually have life partners with similar educational backgrounds and professions, which can promote family harmony. Meanwhile, better-educated parents are more likely to live in a safe neighborhood and have stable family lives, providing sufficient material and spiritual support and developing healthy habits for their offspring (37, 38). In turn, better-educated adults can obtain decent jobs with higher salaries, relieving their parents' budget constraints, and making good use of health resources for physical examination and chronic disease management (39).

However, the long-term existence of uneven distribution of educational resources due to the Hukou system causes the segmentation of the labor market, the fragmentation of economic status, lifestyle, and social interaction, and the reproduction of health inequality (40). In the stage of compulsory education, rural schools are left behind in basic equipment, quality of instruction, attracting highly qualified teachers, peer influence, parental expectations, and extracurricular training (41, 42). As a result, the opportunity to attend high school is biased toward urban residents. Moreover, schools in rural areas lack a physical exercise curriculum, sports facilities, and health concepts, leading to low health literacy among rural students from an early age (43, 44). Although access to higher education has increased with the college enrollment expansion policy, there is still uneven distribution of higher education due to the impact of family background and magnified regional differences (45). According to the maximum maintenance inequality hypothesis and the effective maintenance inequality hypothesis (46, 47), the superior class will crowd out the educational opportunities of the inferior class, preventing the elimination of inequality until the educational opportunities are saturated for the superior class. Moreover, the type of inequality transforms from the simple quantity to the differences in quality of enrollment and level of the university. Constrained by economic conditions and cultural horizon, it is more difficult for rural residents to succeed in the college entrance examination (48), and they are even more likely to make a “rational” decision to give up their education. Therefore, hypothesis 1 is proposed based on the disparities between urban and rural China.

Since the access to higher education is limited, highly competitive, and selective, rural students have to make greater efforts and overcome more barriers to secure college admission. The opportunity for urban residents to attend university was 3.4 times that of rural residents among those born between 1975 and 1979, which increased to 5.5 times among those born between 1980 and 1985 (50). Higher education attainment may not make rural students and their families happier because of the high cost, low rates of return, and a prolonged period of investment (51). Wang et al. demonstrated that the positive spillover effect of higher education is significant only in urban families (52). Moreover, after the expansion policy, the job market is flooded with college graduates (over 10 million), leading to the devaluation of diplomas and the mismatch with the employers' demand. Worse still, the labor market segmentation occasioned by the hukou system exposes graduates from rural areas to a higher risk of unemployment and low-wage employment.

Additionally, Grossman proposed that everyone obtains the initial health stock at birth through heredity, which is maintained or improved through later individual or public investment (53). There are disparities in health stock between urban and rural residents caused by endowments and social determinants. According to the “resource multiplication” or “add protection” theory (54, 55), education has multiplicative health benefits for an advantaged subpopulation. Urban residents have a preference for a healthy lifestyle, which can be solidified and reinforced through the process of education. However, it is more difficult for rural residents to obtain and translate educational gains into health benefits for the whole family due to the lack of a health concept and health resources (56). Moreover, accessing higher education is a crucial ladder for career development and social status for rural residents. While for urban residents with superior congenital conditions, higher education is more about cultural expectations and spiritual pursuit than just making a living. Thus, rural residents may suffer greater psychological deprivation and family-raising pressure when encountering negative events such as economic slumps and unemployment, which reduce their perception of happiness and family wellbeing (57). As a result, hypothesis 2 is proposed.

According to the life course theory (49), the health benefits of education differ depending on the stage of education. When the educational level is relatively low, increasing years of schooling (YS) can greatly improve the health status; however, beyond a certain threshold, continued increase can hardly have a health premium. In western studies, although individuals with a secondary education diploma have the highest perception of happiness, the “marginal” health promotion “increment” is reduced after individuals obtain a college degree (58, 59). Highly-educated people tend to have higher expectations and are usually in a state of tension, anxiety, and disappointment, which may in turn offset the potential mental health benefits (60). For example, Avendano et al. found that increasing YS could incur psychological stress and emotional burdens (61). Even worse, these negative emotions are usually ignored or even suppressed, which increases the risk of unhappiness. In 2019, Nature investigated more than 6,300 doctoral students around the world and 36% of respondents had sought help because of anxiety or depression (62). Besides, the rate of sleep problems and suicide attempts has increased among Chinese college students from 2010 to 2020 (63). Hypothesis 3 is proposed that a non-linear relationship exists between education and health.

The work-family conflict (WFC) occurs when demands and negative moods experienced in the work domain spill over into the family domain, which potentially undermines wellbeing, family functioning, and social relationships (64–69). WFC is significantly related to affective disorders including anxiety, depression, and suicidal ideation (70, 71). Frone et al. posited that mediates the relationship between work and family microsystems (65). Aryee et al. found that WFC mediates the effects of paid work and family systems on individual and family outcomes (72), including job and family satisfaction, psychological health (73), marital tension (74), and parenting (75). Highly-educated people are more engaged in administrative management, and professional or technical work under a greater cognitive load, leading to extensive exposure to electronic products, irregular diet and rest schedules, lack of exercise, depression, and chronic diseases (76). The work stressors and negative affect can cross over within families and ultimately lead to family dysfunction (77, 78). Therefore, hypothesis 4 is proposed.

To the best of our knowledge, this is the first study to examine the relationship between YS and FH using national representative data. Although several previous studies have explored the material returns of education, health benefits—as significant non-material returns of education—need more attention (92). Health is shaped by interaction with the family, community, and society. Instead of the individual-focused approach, the current study analyzed the family-centered health benefits of education, which can help release the positive externalities of education. Family is the basic “cell” of society in China, and FH forms the cornerstone of national health, which is a significant indicator for the implementation of health policy and allocation of social resources. Chinese people have strong family consciousness, and health-related knowledge and skills can be disseminated through kinship links, benefiting family members (93). Sharing information related to health care and disease prevention among families, especially during the COVID-19 pandemic, can build a culture of health, and foster family resilience and wellbeing (94–96).

In the process of building a moderately prosperous society, the principal contradiction between people's needs for a better life and unbalanced and inadequate development should be overcome. Besides medical factors, health status can be affected by social determinants to a certain extent, hence, health promotion should be extended to cultural, psychological, and social perspectives. By expanding from micro, middle, to macro levels, the study clarifies the internal relations among individuals' education, family health, and social structure, which is of great value to address systemic vulnerabilities, improve practices, and ensure more equitable education and health outcomes.

First, we found disparities in FH, educational attainment, household income, healthcare coverage, and job type between urban and rural China, and education inequality can translate into health inequality. There is uneven distribution and utilization of public resources, with low health awareness and inadequate medical security in rural China (80). Second, in general, education may have a positive effect on FH both for urban and rural residents. However, there is no simple linear relationship between education and health. Our study found an inverted-U relationship between YS and FH, which illustrates an upper limit of the “health dividend” of education. Increasing education beyond a certain threshold may not have health benefits (97). Higher education may negatively affect health. Previous studies demonstrated that people with higher education are more likely to be diagnosed with hypertension and psychological distress (98), and to drink more and exercise less (99). In the present study, health benefits declined at the turning point of 17.1 YS in the urban subsample, which occurred earlier in the rural subsample at 13.7. This suggested that rural residents, obtain limited FH benefits from higher education (52). One study suggested that minoritized racial groups generally experience poorer health and obtain fewer health benefits from education (100). Besides, the proportion of higher education is significantly lower among residents of rural hukou (101). It takes more effort for individuals and their families to attain higher education (102). However, they have more material expectations for higher education because of the long-term investment (103). Moreover, they have to overcome more risks to withstand the screening of the labor market (57). Through mechanism analysis, we discovered that highly-educated people face stronger WFC, which undermines the FH benefits of education. One compelling explanation may be that highly-educated people usually migrate to first-tier cities with rapid economic development and higher living standard, where the work intensity and competitiveness encroach on their time and energy devoted to their families (104, 105), thus, they are faced with difficulties such as family regulation and family health management. It is more challenging for rural residents to settle in first-tier cities due to the inherited disadvantage in endowments and resources (42).

The study indicates the health benefits of different educational stages and heterogeneity of the impacts of Hukou. Education can exert substantial, lasting, and wide-ranging health benefits by modifying health behaviors, enhancing healthy psychology, and strengthening social interactions (106). Therefore, policymakers, healthcare practitioners, and educators, should develop joint strategies to suppress the health disadvantages caused by social factors. Besides, the gradient upgrading of human capital should be encouraged in rural areas through the consolidation of compulsory education, the popularization of high school education, and the extension of higher education. Meanwhile, the social inequalities caused by education should also be negated. Our study supports the “resource multiplication” theory, the advantages of urban residents in cultural resource stock and the utilization efficiency further widens the urban-rural health inequality. This suggests that strategies to prevent vulnerable groups from falling into the happiness “trap” of education, that is, to pursue education and self-development at the cost of individual health and family happiness should be developed.

In this study, we only measured the YS by an individual rather than the whole family. Notably, educational attainment can be influenced by the family to some extent. Thus, although the robustness of the results was high based on PSM and the substitution of the dependent variable, the causal relationship between education and health cannot be concluded given the cross-sectional nature of the data analyzed in this study. Future studies should explore and compare the health benefits of different educational stages, such as compulsory education, high education, and associate, bachelor, and postgraduate education. It should be on that the data used in this study was collected during the pandemic, and thus whether the findings can be generalized to other contexts before or after the pandemic should be further explored. Moreover, the extent of work-family conflict faced by people of different genders and occupational types, and how it mediates the relationship between education and health need to be analyzed in future.

In summary, health development and promotion are embedded in the family unit and social structure. The present study contributes to family-centered health promotion and targeted interventions for urban and rural populations, respectively. Contrary to the intuition that education can promote social equity, this study reveals that uneven distribution and utilization of educational resources exacerbate health inequalities between urban and rural China. In addition, health dividend decreases after higher education. WFC is believed to be the negative mechanism of the education-FH nexus, which warns highly-educated people to avoid falling into the happiness “trap” of education and maintain a balance between work and family. However, this requires the joint efforts of the government, educational and health institutions, and the labor market to broaden externalities in education.

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

The studies involving human participants were reviewed and approved by Jinan University. The patients/participants provided their written informed consent to participate in this study.

CJ and YL: conceptualization and methodology. CJ: software. YL: writing—original draft preparation. XLu and XLi: writing—review and editing. WZ and YW: supervision and project administration. All authors have read and agreed to the published version of the manuscript.