**4. Discussion**

The present study aimed to extend research on the link between conscientiousness and health by examining whether there is a reciprocal relationship between conscientiousness and well-being (subjective and physical well-being) using a cross-lagged design in a sample of Chinese undergraduate students. The results indicated that after controlling for the effects of gender, age, BMI, SES, and the prior level of conscientiousness, conscientiousness prospectively predicted subjective well-being (indexed by positive affect, negative affect, and life satisfaction) and physical well-being (indexed by self-reported physical symptoms). However, subjective and physical well-being didn't prospectively predict conscientiousness. Therefore, the reciprocal relationship between conscientiousness and well-being was not confirmed in the current sample of Chinese undergraduate students.

We found that conscientiousness prospectively predicted subjective well-being indexed by positive affect, negative affect, and life satisfaction among Chinese undergraduates. These findings replicated previous evidence that individuals with high conscientiousness reported more frequent positive affect, greater life satisfaction, and less frequent negative affect [12,14,16], revealing that conscientiousness is a robust and prospective predictor of subjective well-being. On the one hand, individuals high in conscientiousness are likely to be more effective at regulating negative affect [18] and may experience less daily stress [27,32]. On the other hand, individuals high in conscientiousness are more likely to be self-disciplined, goal-directed, industrious, and rule-abiding [4], and their efficient

and reliable performance may promote success in school or the workplace [5,6,8,9]. Such success can help to enhance their subjective well-being [12]. Additionally, individuals high in conscientiousness may be more successful in building stable and satisfying interpersonal relationships, which in turn may contribute to enhanced feelings of subjective well-being. In contrast, individuals low in conscientiousness may have difficulty developing or maintaining adaptive interpersonal relationships, which in turn may contribute to decreased feelings of subjective well-being over time [7].

Similarly, our study found that conscientiousness prospectively predicted physical well-being indexed by self-reported physical symptoms. This finding is the preliminary evidence to demonstrate the predictive effect of conscientiousness on physical well-being in the sample of Chinese undergraduates, which is consistent with the results found in the samples from Western countries [10,29,55,56]. Individuals low in conscientiousness reported more physical symptoms and negative health outcomes as compared to individuals high in conscientiousness. Researchers have proposed that conscientiousness may protect physical health by promoting favorable health behaviors and avoiding detrimental health behaviors [11,57]. Conscientious individuals tend to pursue higher quality of life and healthier life paths, such as engaging in more physical exercise and outdoor activities, and adhering to treatment and medication because of being self-disciplined and responsible [58,59], which is more conducive to physical health. While less conscientious individuals tend to be characterized by poor self-control and self-discipline and often have unhealthy lifestyles, such as poor diet and lack of exercise, which increases the risk of chronic diseases [60–62]. Personality is a determining factor for key outcomes across the lifespan, with the similar predictive validity to socioeconomic status and cognitive ability [57]. Therefore, it is of grea<sup>t</sup> significance to identify conscientiousness as a personality indicator of physical well-being.

Contrary to our hypothesis, this preliminary exploration into the reciprocal relation between conscientiousness and well-being among Chinese undergraduate students did not find prospective predictive effects of subjective well-being and physical well-being on conscientiousness. In other words, individual differences in conscientiousness can explain differences in subjective and physical well-being, but are less likely to be explained by differences in subjective and physical well-being. In the context of Chinese culture, conscientiousness is a highly valued trait shaped by collectivist cultural values. School and family education in China especially pay attention to the cultivation of culturally valued traits among children and adolescents [63]. From childhood, students are guided to develop the right values, a proactive view of themselves, and culturally valued traits, especially conscientiousness. Individual personality traits do change after adolescence and most change for the better; the changes that occur in adulthood, while clearly for the better, are smaller in magnitude than during childhood and adolescence [64]. Thus, individual differences in conscientiousness are less likely to be affected by differences in well-being during emerging adulthood than during childhood and adolescence. At least in the sample of this study, we did not demonstrate that subjective and physical well-being were prospective predictors of conscientiousness over a one-year interval. Future research could explore the reciprocal relationships between conscientiousness and subjective and physical well-being in children and adolescents.

## *4.1. Practical Implications*

Not only can personality change, it can substantially change with the general maturation process and personal circumstances [64,65]. The findings of this study sugges<sup>t</sup> that cultivating conscientiousness may help to improve physical and mental health, in addition to other interventions specifically designed to improve physical and mental well-being. Education policymakers and educators may wish to consider the following recommendations for interventions related to promoting conscientiousness, particularly for undergraduate students with low conscientiousness. First, create a safe, supportive, orderly, and minimally distracting environment that fosters students' sense of belonging. Second, help

students to internalize relevant social norms (e.g., rule compliance) to form internalized values. Third, cultivate developmentally appropriate skills related to conscientiousness, such as goal setting, time management, progress monitoring, and self-regulation. Finally, support students to work toward long-term goals that are achievable, challenging, and personally meaningful.

#### *4.2. Limitations and Future Directions*

Several limitations of the present study should be considered. First, the present study relied on a sample of undergraduates and thus the conclusions need to be further tested in a more general population in the future. Second, the present study used only a two-wave cross-lagged design with a one-year interval, a longitudinal design with more waves and longer time intervals should be adopted to establish the causal relationships between conscientiousness and well-being more reliably and accurately in future studies. Third, the lack of attention to balancing male and female participants in the study design limited the interpretation of the current findings, and future research should address this issue. Finally, this study included only self-reported physical symptoms as a measure of physical well-being. Future research could employ more objective indicators of physical well-being.
