The term “emotion” is traditionally regarded as the result of the changes of physiological systems ^[1][33] or psychological appraisals based on individual objectives and well-being ^[2][34], involving physiological stimuli and responses, psychological cognition, and behavioral disposition and manifestation ^[3][35]. However, it is increasingly viewed as a socially constructed concept whose connotation and expression are defined by cultural ideology, beliefs, norms, rituals, and social structures ^[4][36]. A case in point is teacher emotions, which are the “complex, multifaceted experiences that arise in a variety of sociopolitical relations and contexts” ^[5][37] (p. xviii). In other words, teacher emotions are constructed through their interactions with students, colleagues, administrators, and other parties in their respective pedagogical, institutional, and sociohistorical contexts. Because teacher emotions are pervasive in the professional practice of teachers ^[6][38] and central to teaching ^[7][8][12,39], it is critical for teachers to manage emotions in their professional life by engaging in emotion labor. The term “emotion labor” was first proposed as “emotional labor” by Arlie Hochschild, who defined it as the emotional management in workplace to “induce or suppress feelings in order to sustain the outward countenance that produces the proper state of mind in others” ^[9][27] (p. 7). Because this type of labor, in addition to physical and mental labor, has exchange value, it can be traded in for a wage ^[10][40].

Admittedly, some teacher researchers prefer the word “emotion” to “emotional” so as to avoid the negative association of the latter in its meanings. Instead they have argued that teachers’ EL is actually a healthy response to challenging conditions in teaching, and an active negotiation or struggle that purposefully seeks agreement among their educational beliefs, professional training, and explicit or implicit emotional rules ^[8][11][39,41]. In addition, the exchange value of teachers’ EL is expanded from merely monetary rewards (e.g., a wage or a salary) to emotional ones (e.g., sense of achievement, social praise, job satisfaction, etc.), which transforms teachers’ EL into a double-edged sword ^[12][42]: on the one hand, it reveals that teachers are restrained or even oppressed by the emotional rules in the cultural, social, or institutional contexts, so that they are qualified to meet the emotional demands of their profession; on the other hand, it legitimizes teachers’ pursuit of emotional rewards, which provides them with a continual driving force in their pursuit of sustainable professional development.

Influenced by the large-scaled, large-sampled quantitative research approach that has dominated the empirical research related to EL, studies on teachers’ EL have also adopted questionnaire survey or scale measurement as a dominant research method, and this tendency has extended to recent work ^[13][43]. A case in point is the three large-scaled surveys among secondary school teachers in Croatia conducted by Buri’c, Penezi’c and Sori’c ^[14][29]. Based on the process model of emotion regulation ^[15][16][44,45], they generalized and categorized teachers’ EL strategies as avoiding situations, active modification, reappraisal, suppression, and tension reduction. Another instance is that, based on a localized Teacher EL Strategy Scale ^[17][46], Yin, Huang and Lee ^[18][25] surveyed 1115 primary school teachers in Hong Kong, and concluded that the EL strategy of surface acting significantly negatively correlated with teacher efficacy, while strategies of deep acting and expression of genuine emotions tend to promote teacher efficacy. In a related study, Zheng, Yin, and Wang ^[19][47] analyzed the relationships between leadership practices, emotional labor strategies, and teacher efficacy by collecting quantitative data from a questionnaire survey that was administered to 1026 primary and secondary school teachers in China. Their principal findings were not only consistent with those of the previous study, but these findings also reinforced the important role of EL strategies in leadership practice; that is, surface acting and a genuine display of emotions significantly mediate the effects of leadership practices on teacher efficacy beliefs. Overall, the majority of these studies analyzed the correlation between these strategies and other variables in teachers’ professional development in addition to describing and categorizing the EL strategies adopted by teachers who work with learners across different age groups (e.g., kindergarten, primary school, university, etc.).

However, such quantitative and descriptive studies are less likely to reveal the contextuality and complexities that underpin teacher EL. To this end, researchers have also explored this popular theme via qualitative and interpretive means. For example, in light of the Confucian culture in China, Yin ^[20][21] interviewed 8 high school teachers, and generalized 7 localized strategies (pretending and restraining, which belong to surface acting; refocusing, reframing and separating, which are categorized as deep acting; releasing and outpouring, which are used by teachers to express genuine emotions to their students) that are commonly utilized in classroom teaching. However, most descriptive or interpretive studies still regard teachers’ EL strategies as a static entity that is related to emotional manipulation and management, or teacher EL.

By contrast, in this paper we argue that teacher EL should be treated as a dynamic process in accordance with teachers’ professional development. Our proposal is in fact inspired by several researchers who have underlined the significance of teachers’ dynamic EL based on “longitudinal studies … (that) will help determine how teachers develop their emotional regulation … strategies” ^[21][48] (p. 395). One of the earliest influential longitudinal studies on teachers’ emotions and EL is Zembylas’s ^[22][5][32,37] work. He conducted a 3-year case study about a primary school teacher, Catherine, and explored her emotional experiences when she taught science in different stages of her professional life. By proposing a longitudinal approach that involved “genealogies of emotions in teaching” ^[5][37] (p. 97), which he describes as “a process of finding out the historicity of emotional experiences” that “casts light on how emotions are located and represented in teachers’ work and personal/professional development” ^[5][37] (p. 98), Zembylas traced the trajectories of Catherine’s emotional experiences and analyzed her EL changes in an implicit manner.

Recently, more researchers have turned their investigative gaze to the temporal dimension of teacher emotions and EL strategies. As for qualitative studies, Taylor, Newberry, and Clark ^[23][49] analyzed the 14-week emotional episodes of the first author who recorded and discussed these episodes with a critical friend. They found out that as she gradually recognized and contextualized her surface emotions, she gained a greater understanding of herself and her deeper emotions, which in turn enabled a more effective practice of emotion regulation and reduced the level of her negative emotions. In another study, Gao and Cui ^[24][50] conducted a longitudinal case study about a team leader and a team member of an English for academic purposes (EAP) teaching team during an institutional curriculum reform in a Chinese university. Based on six rounds of interviews over two and half years, they tracked their EL changes and found that both of the team leader and team member applied the EL strategy of genuine expression most frequently, and deep acting least frequently; but due to their different identities and team roles, the team leader experienced increasingly intense and frequent EL, while the team member’s EL tended to decrease in intensity and frequency.

At the same time, however, a few quantitative studies have also started to investigate the progression of teachers’ emotional experiences and regulation in their professional life. For instance, Lavy and Eshet ^[25][51] investigated the daily dynamics of emotional experiences of 62 teachers, who completed daily measures of their own emotions, emotion regulation, burnout, and job satisfaction during a span of 10 workdays. The authors also confirmed the linking of teachers’ emotions and their EL strategies, namely the negative spiral effects of teachers’ negative emotions and surface acting, as well as the positive spiral of their positive emotions and decreased surface acting. In addition, the results of their study highlighted the obvious impacts of both negative and positive spirals on teachers’ burnout and job satisfaction in their professional development.