1. Introduction
Research on job satisfaction (JS) has a long history [
1]. Numerous studies have indicated that JS represents one key indicator of employees’ psychological well-being at work [
2,
3] and that it is one significant antecedent of employees’ work performance [
4], work behavior [
5], commitment [
6], job stress [
7], turnover intention [
8], and organization success [
9]. Notably, it is reported that teachers’ satisfaction levels are lower and stress levels are higher than other professional groups in many countries [
10,
11]. This is especially true for science, technology, engineering, and mathematics (STEM) teachers [
12,
13]. Considering that JS can directly impact turnover intention [
8], low satisfaction levels have led to high turnover rates and thus exacerbated the shortages of STEM teachers [
13]. Hence, to address this issue, it is very necessary to explore what factors influence STEM teachers’ JS. Furthermore, studies have revealed the significance of STEM teachers’ JS in the process of improving the quality of STEM education [
14] and students’ STEM learning outcomes [
15]. This also highlights the importance of increasing STEM teachers’ JS. However, to date, few studies have focused on the predictors of STEM teachers’ JS [
16].
There is a consensus that the initial years of employment are one of the most important segments of teachers’ professional careers [
17]. If teachers do not feel satisfied with their jobs in their novice stages, they may be dissatisfied with their jobs throughout their teaching careers [
17]. Hence, more attention should be paid to the exploration of novice teachers’ JS and its antecedents. However, until now, very few studies have set out to understand novice STEM teachers’ JS.
Nowadays, the job demands–resources (JD-R) model is widely applied to explore teachers’ JS [
18,
19]. Despite this, limited studies have confirmed its validity in the field of STEM teacher education [
16]. Furthermore, some scholars have argued that “personal resources can have the same function as job resources” and thus suggested that personal resources should also be incorporated in the model [
20] (p. 2). However, this argument has not been widely substantiated.
Motivated by the abovementioned three gaps, our study explores the antecedents of novice STEM teachers’ JS. Prior research has found that teachers’ JS may be decided by many antecedents [
21], such as work conditions [
22], work–life balance [
23], and so on. In light of the JD-R model, we focus on the roles of teachers’ personality traits (PTs) and perceived social support (PSS), which are representative factors of personal resources [
24] and job resources [
25], respectively, on JS. In addition, according to the JD-R model, we examine the mediating role of work engagement between the two factors and JS. A cross-sectional methodological approach is adopted, and 2592 novice STEM teachers from both urban and rural areas in China are recruited in this study. A new model is validated to show how novice STEM teachers’ personality traits, perceived social support, and work engagement influence their JS.
2. Literature Review and Hypotheses
The JD-R model was first proposed by [
26]. It posits that job characteristics can be classified as job resources and job demands [
26]. Job demands related to work cost negatively impact employee well-being, while job resources related to work support positively impact employee well-being [
26]. It should be noted that the impact of job resources and job demands on employee well-being is independent [
16]. In other words, when it comes to employee well-being (including JS), job resources and job demands can be discussed together or separately. We mainly examine the effects of job resources on JS in this study.
Specifically, based on [
26], job resources are “those physical, social, or organizational aspects of the job that may do any of the following: (a) be functional in achieving work goals; (b) reduce job demands and the associated physiological and psychological costs; (c) stimulate personal growth and development” (p. 501). Particularly, social support represents an important kind of job resource. This is because sufficient support from employees’ families, colleagues, friends, and others in their social networks can help individuals achieve their work goals, improve their psychological states, and promote their professional development [
27]. The term perceived social support (PSS) can be used to describe “the degree to which individuals believe they have social support” [
28] (p. 63).
The significant effects of PSS on JS have also been confirmed among different kinds of employees, such as bank staff [
29], traffic enforcement agents [
30], and nurses [
31]. However, this impact has yet to be validated among STEM teachers. We hypothesize the following:
Hypothesis 1 (H1). Novice STEM teachers’ perceived social support will significantly impact their job satisfaction.
Over the past years, much effort has been made to develop the JR-D model [
16,
32]. For instance, it is argued that individuals who have sufficient personal resources can also receive a series of work support, which may further increase employees’ satisfaction [
20]. Specifically, personal resources describe an individual’s sense of their capabilities to successfully control and influence their environments [
33]. Individuals without personal resources are more likely to be affected by the negative aspects of their working environments [
20,
32]. On the contrary, individuals with rich personal resources are more likely to be resilient and may not be influenced by the working environments easily [
20,
32]. In this sense, personal resources are no less important than job resources and should also be considered when predicting JS [
20,
32]. As personal resources are as important as job resources in predicting JS [
20,
32], it may be meaningful to incorporate personal resources into the JR-D model.
Particularly, numerous studies have pointed out that individuals’ personality traits (PTs) are their important personal resources [
33,
34,
35,
36]. Specifically, the term PT is defined as “the characteristics that are stable over time, provide the reasons for the person’s behavior, and are psychological in nature” [
26] (p. 448). Generally, PTs include five big factors, namely, openness, conscientiousness, extroversion, agreeableness, and neuroticism/emotional stability [
37,
38]. Emotional stability is the antonym of neuroticism [
38]. In our study, we choose to use the term emotional stability instead of neuroticism. PTs can, to a large extent, determine individuals’ “affective, behavioral, and cognitive style” [
26] (p. 440), including the style of perceived social support. To date, the impact of PTs on PSS has been validated among high school students [
39], university students [
40], and middle-aged adults [
41]. However, this impact has yet to be confirmed among STEM teachers. We hypothesize the following:
Hypothesis 2 (H2). Novice STEM teachers’ personality traits will significantly impact their perceived social support.
As aforementioned, it is argued that personal resources are also significant antecedents of JS and should be incorporated into the JR-D model [
18,
20]. A lot of research has also indicated that employees’ PTs, as one of the personal resources, will predict their satisfaction [
37,
42,
43,
44]. For instance, one study detected that the big five factors of PTs had a multiple correlation of 0.41 with JS [
37]. This revealed that PTs, as a composite construct consisting of five factors, is one significant antecedent of JS [
37]. However, the impact of PTs on JS has yet to be confirmed among STEM teachers. We hypothesize:
Hypothesis 3 (H3). Novice STEM teachers’ personality traits will significantly impact their job satisfaction.
Work engagement (WE) is a “positive, fulfilling, work-related state of mind that is characterized by vigor, dedication, and absorption” [
45] (p. 74). The JD-R model postulates that WE can mediate the effects of job resources on employees’ psychological well-being (including JS) [
20,
45,
46]. Karatape et al. also proposed a conceptual model illustrating that sufficient job and personal resources can impact WE directly, and WE may further impact JS [
47]. On the one hand, job and personal resources will help employees realize their goals, and employees with sufficient job and personal resources are more likely to be committed and engaged as they can derive fulfillment from their work [
48]. On the other hand, engaged teachers usually perform well in their schools and gain positive experiences [
49,
50] and thus will feel satisfied with their jobs [
50]. As TS is one important factor of personal resources and PSS is one important factor of job resources, it can be assumed that WE may mediate the impact of TS and PSS on JS. Specifically, firstly, prior research has elucidated that the big five factors of PTs can exert effects on WE [
51]. For instance, in one meta-analysis, researchers confirmed that all of the five PTs are significant antecedents of WE [
51]. Secondly, the assumption that PSS can predict WE has also been justified in two previous studies [
52,
53]. Thirdly, the assumption that WE is one antecedent of JS has also been verified in one prior meta-analysis [
54]. Notably, although these relationships have been confirmed in some prior studies, they have seldom been detected among novice STEM teachers. We hypothesize the following:
Hypothesis 4 (H4). Novice STEM teachers’ perceived social support will significantly impact their work engagement.
Hypothesis 5 (H5). Novice STEM teachers’ personality traits will significantly impact their work engagement.
Hypothesis 6 (H6). Novice STEM teachers’ work engagement will significantly impact their job satisfaction.
Hypothesis 7 (H7). Novice STEM teachers’ work engagement will mediate the impact of perceived social support on job satisfaction.
Hypothesis 8 (H8). Novice STEM teachers’ work engagement will mediate the impact of personality traits on job satisfaction.
Additionally, considering the hypothesized impact of PTs on PSS (see H2) and the hypothesized mediating role of WE between PSS and JS (see H7), it can be assumed that PSS and WE may serially mediate the impact of PTs on JS. However, to the best of our knowledge, this serial mediating effect has never been validated before. Hence, we propose our ninth hypothesis to help better understand the roles of PSS and WE in predicting JS.
Hypothesis 9 (H9). The impact of novice STEM teachers’ personality traits on job satisfaction will be serially mediated by perceived social support and work engagement.
Finally, considering the hypothesized impact of PTs on PSS (see H2) and the hypothesized impact of PSS on JS (see H1), we propose our final hypothesis. It should be noted that this mediating effect has never been verified in STEM teacher education.
Hypothesis 10 (H10). Novice STEM teachers’ perceived social support will mediate the impact of personality traits on job satisfaction.
Based on the above-mentioned arguments, we propose the conceptual model for our study (see
Figure 1). Our model is drawn from the JD-R model [
26]. Firstly, the JD-R model suggests PSS (as one kind of job resource) will impact WE and JS [
26]. Secondly, we adopt Kwon and Kim’s and Radic et al.’s advice and incorporate personal resources into the JD-R model [
20,
46]. In our model, personal resources are given the same importance as job resources. Hence, the variable PTs (as one kind of personal resource) is assumed to influence WE and JS. Thirdly, considering the impact of WE on JS indicated by the JD-R model [
20,
45,
46], our model also assumes that WE can mediate the impact of PSS and PTs on JS.
The proposed conceptual model has filled at least three theoretical gaps. Firstly, although the JD-R model’s validity in predicting employees’ JS has been justified in various fields (e.g., healthcare professionals, mariners) [
18,
19], to date, it has rarely been applied in STEM education, and its power in predicting STEM teachers’ JS remains unknown [
16]. To fill this theoretical gap, we propose the conceptual model, which is based on the JD-R model, to explore the antecedents of novice STEM teachers’ JS. Secondly, prior studies applying the JD-R model paid little attention to the impact of personal resources on JS [
20,
32]. In other words, the roles of personal resources were usually ignored in studies applying the JD-R model. To fill this gap, the proposed conceptual model expands the JD-R model by incorporating personal resources. It articulates that personal resources are as important as job resources in predicting JS. Thirdly, most prior studies paid attention to the direct relationships among the JD-R model [
16,
17], while the indirect relationships were seldom examined. To fill this gap, our model posits that PSS and WE can serially mediate the impact of PTs on JS, which has never been studied before. This mediating effect adds to the current understanding of the roles of PSS and WE in predicting JS.