Sustainability requires the protection of natural and human (social) environments. Activities related to social sustainability are referred to as sustainable behavior. Sustainable behavior is intended to save and protect limited natural resources, allow equitable access for everyone, and to foster cooperation and assistance among people [1
]. Sustainable behavior takes into consideration the needs of both current and future generations, and is exhibited by pro-ecological behavior, equity, and altruistic behavior [3
]. Pro-ecological behavior is purposeful behavior dedicated to the conservation and protection of natural resources; equity is defined as the equitable access to resources, based on the consideration of both present and future generations; and altruistic behavior is behavior designed to enhance human well-being by maximizing others’ interests rather than one’s own interests [4
]. Steady efforts have been made since 1992 to implement sustainable behavior in educational settings, but the outcomes of the efforts have been scarce due to a lack of clear understanding of sustainable behavior. Social sustainability and equity in education affect a learner’s well-being. Therefore, educators need to take a new approach in teaching sustainable behaviors and changing attitudes to align with these behaviors.
In recent years, a growing number of studies have examined sustainable behavior in relation to educational and psychological factors; happiness research is the primary example [5
]. Happiness is an expected outcome of participating in sustainable development. Lykken and Tellegen [6
] maintained that, among variables that influence a person’s happiness, 50% are genetic, 10% are environmental, and 40% are inner activity. Inner activity includes everything that people think and do in everyday life. Emmons and McCullough [7
] classified inner activity into three types: Thanking others, acting kindly to others, and setting up a personal goal or planning a meaningful activity. Happiness is generated from these behavioral strategies, which are indicators of sustainability [8
]. People who engage in pro-ecological behavior were found to perceive themselves as happier than those who do not, and individuals who care about fairness experience a high level of subjective well-being [9
]. In addition, cooperative, compassionate, and altruistic people, who accommodate others’ requests, were found to experience greater happiness [10
]. These study results demonstrate positive psychological outcomes of sustainable behavior.
] argued that education and training for a better future contribute to happiness. It is, therefore, advantageous to facilitate both students’ understanding of environmental problems and their involvement in solutions through an education that contributes to sustainable development.
Study engagement is a positive study-related state of mind, and includes passion, dedication, and commitment [12
]. It refers to the investment of effort in study, i.e., being strongly involved in study. It includes a behavioral (e.g., effort) and affective (e.g., enjoyment, positive attitude about study) subtype [14
]. Engagement related to good health and has a positive affect [16
]. Chambel and Curral [17
] reported that students who are deeply engaged in learning show both a high level of academic performance and a positive well-being. Other research has shown that an engaged person experiences greater levels of well being [18
]. This implies that engaging in study helps individuals experience happiness.
In a study on measures to facilitate a positive learning status, Ouweneel et al. [20
] found that thanking others and exhibiting altruistic and kind behaviors provoke positive learning-related emotions. It was found that students experienced positive emotions by engaging in kind behavior, and this facilitated students’ engagement in learning [21
]. Christenson et al. [22
] also demonstrated that both behavioral and affective components play important roles in student engagement. This suggests that experiencing positive emotions from engaging in behavior leading toward a common good results in a deeper engagement in learning, which contributes to subjective well-being and happiness.
The results of previous studies suggest that participating in sustainable behavior to protect natural and human environments contributes to individuals’ engagement and happiness; positive emotions—such as happiness—in turn, contribute to learners’ well-being. Happiness can transform an individual and facilitate positive behavior. Educators, therefore, must pay attention to students’ happiness. Studies on sustainable behavior and positive psychological factors are, unfortunately, significantly lacking. Therefore, this study aims to investigate the structural relationships among sustainable behavior, study engagement, and happiness, in college undergraduates, to inform the direction of sustainable education and student happiness.
The subjects of this study were 202 undergraduate students who volunteered. Participants were recruited from metropolitan areas in South Korea. The questionnaire was administered to undergraduates during the last week of the fall semester. Of the study population, 103 participants (51%) were male and 99 participants (49%) were female. Of those participants, 51 (25.2%) were first year students, 72 (35.6%) were in their second year, 43 (21.3%) were in their third year, and 36 (17.8%) were in their fourth year. The students ranged in age, from 20 to 32; the mean age was 22.9.
Sustainable behavior was measured using the Sustainable Behavior Scale [45
]. This scale consists of three factors; pro-environmental behavior, altruistic behavior, and fairness, and includes twelve items measuring the frequency of participation in sustainable behavior on a five-point Likert scale. An example of a pro-environmental items is: I recycle paper; altruistic behavior: I yield my turn to those who are in a hurry; and fairness: Everyone has a right to education. Higher scores indicate a higher level of behavior in the factor measurements. The scale reliability was 0.85. Study engagement was measured using the Study Engagement Scale [46
], which is based on Gallini, Sarah and Moely’s (2003) [47
] academic engagement study. Study engagement items included: I enjoy taking classes; I am interested in this course; and I try to apply what I learn from class to real life; this scale consisted of three items. The items were five-point Likert scaled and the scale reliability was 0.76. Happiness was measured using the happiness scale [46
], which is based on Lyubomirsky and Lepper’s (1999) [48
] happiness theory. The happiness scale consisted of a single factor of three items on five-point Likert scale. The happiness items included: I am happy, I enjoy my life, and I am satisfied with my life. The scale reliability was 0.72.
4.3. Data Analysis
This study aimed to determine the structural relationship among undergraduate students’ sustainable behavior, study engagement, and happiness. The study was conducted by establishing research models, based on previous studies, and compared Models 1 and 2. To evaluate the model fit of structural equations, maximum likelihood was used, and the model fit was compared using χ2 (chi-squared statistics), χ2/df (degree of freedom), root means square error of approximation (RMSEA), comparative fit index (CFI), and the Turker-Lewis index (TLI). Following the model-fit comparison, the model with greatest parsimony and validity was selected as the final model, direct and indirect effects and path coefficients of the final model were then examined. The comparison of model fit and direct and indirect effects was conducted using Amos 18.0 (IBM: Armonk, NY, USA). Reliability and correlations among variables were investigated using SPSS 19.0 (IBM: Armonk, NY, USA).
This study was conducted to investigate the relationships among sustainable behavior, study engagement, and happiness. Specifically, it modeled structural relations on the variables and investigated the influence of sustainable behavior on learners’ happiness, mediated by study engagement. The study created two models: Model 1, in which sustainable behavior has direct and indirect effects on happiness, mediated by study engagement; and Model 2, in which sustainable behavior has an indirect effect on happiness, mediated by study engagement, and then compared them. Based on the results of the comparison, Model 1 was chosen as the final model, and it was found that sustainable behavior has direct and indirect effects on happiness, mediated by study engagement. Additionally, this study explored the moderating effect of study engagement. The result showed that sustainable behavior and study engagement had significant effects on happiness; however, there was no significant association effect in this survey.
The results of the mediation analysis suggested that college students’ sustainable behavior was positively associated with study engagement, and study engagement was positively associated with happiness. This result is consistent with Corral-Verdugo et al. [43
] and Zelenski and Nisbet [51
], who that reported a positive relationship between sustainable behavior and happiness, and Chambel and Curral [17
], who examined the effect of students’ engagement on happiness. In addition, the results correlate with Salanova et al. [31
] and Howell [32
], who argued that engagement requires self-control and autonomy. Sustainable behavior is deliberate and effective [4
]. Study engagement is in a range of educationally purposeful activities [52
]. These factors need both self-control and a positive perspective. Prior studies also demonstrated that people’s happiness is under their control and motivation [53
In the present study, study engagement was positively correlated with pro-environmental behavior, altruistic behavior, and fairness; altruistic behavior showed the highest correlation with study engagement. This provides partial support for the findings of Pekrun et al. [21
], which identified positive relationships between gratitude, kind behavior, and study engagement. In the relationship between sustainable behavior and happiness, fairness showed the highest correlation with happiness.
The results of this study suggest that behavior management, such as sustainable behavior and engagement, influence the happiness of college students. This further suggests that students who have concern for society and others—who can control and regulate their behaviors for that purpose—can also be engaged and committed in an educational setting by controlling their behaviors. Sustainable behavior is to consider the well-being of future generations, moving beyond mere conservation of resources. Moreover, a sustainable behavior affects other sustainable behaviors, and, consequently, catalyzes entire sustainable behaviors and systems. Therefore, for a sustainable society and the future of humanity, it is important to teach an effective management of given resources, and cultivate minds and attitudes toward a concern for others.
Learners’ happiness is associated with personal well-being, as well as academic success [55
]. For this reason, happiness is an important issue for both individuals and society. Diener [27
] argued that, in happiness, subjective judgment of how people feel about their lives is more important than the objective criteria. In that context, this study aimed to investigate sustainable behavior that requires learner’s autonomic control and values in relation to educational settings and happiness. This study will contribute to an increase in understanding, and will make advances in a learner’s well-being and life in a sustainable society.
Although the results of this study can provide significant implications for a learner’s studies and well-being, and sustainable society, this study may have limitations due to inclusion of study participants from specific regions and age groups. Additionally, this paper may potentially have a weakness due to sample size. Although a minimum sample size of 200 is recommended for accurate parameter estimates [56
], this research does not have a large enough sample size. Future studies should consider a broader sampling and socio-demographic characteristics. Additional exploration on antecedent and outcome variables of sustainable behavior and happiness is also necessary. Engaging in positive behavior boosts happiness by satisfying psychological needs, such as self-control and competence [18
]. In addition, happy people perceive a high degree of control and exhibit environmental morals [57
]. Therefore, happiness can be measured as possibly both dependent and independent variables. Both study outcomes make an important contribution to future research. These efforts are expected to enhance learners’ awareness regarding the well-being of environment and society, and further lead to fostering a learning environment that emphasizes positive psychology.