Organizational Citizenship Behavior Motives and Thriving at Work: The Mediating Role of Citizenship Fatigue

: Employees can a ﬀ ect the sustainability of organizations, yet the di ﬀ erent e ﬀ ects of employee organizational citizenship behavior motives on employee thriving at work, as elements of organization sustainability, are not clear. Based on self-determination theory and conservation of resource theory, this study examined whether organizational concern motives and impression management motives behind employees’ organizational citizenship behaviors are di ﬀ erently associated with their citizenship fatigue and their subsequent thriving at work, and whether task performance moderates these relationships. Results from a multi-wave and multisource study using a sample of 349 employees show that organizational concern motives had a positive indirect e ﬀ ect on thriving at work through reducing employees’ citizenship fatigue, while impression management motives will undermine thriving at work through inducing citizenship fatigue. This study further found that task performance strengthened the positive relationship between impression management motives and citizenship fatigue. The theoretical and practical implications of these ﬁndings are discussed.


Introduction
A sustainable organization is viewed as an organization where employees are actively involved in a sustainable process of learning and change. As a factor of human sustainability and sustainable performance, thriving at work has recently become popular in the organizational behavior field [1][2][3][4]. Thriving at work refers to a psychological state in which employees experience a sense of learning and vitality during their working time [5]. Thriving employees are usually actively and sustainably learning and growing, and at the same time, they are more likely to engage in extra-role duties and contribute to the organization. Some studies have found that employees who are thriving at work engage in more organizational citizenship behavior (OCB) [6,7]. However, enacting OCB may consume individual resources, make the actor feel drained [8], and create excessive work stress [9]. This raises an interesting and important question: How will employees' psychological state of thriving change after they enact OCB? The impact of employee OCB on employee thriving at work, which is not clear, can affect not only employee career development but also organization sustainability.
OCB refers to how voluntary employees' discretionary behavior, which is not directly rewarded, can benefit the organization [10]. Research has revealed that OCB may have different effects. On the positive side, OCB is positively related to sustainable performance [11], and a great deal of research has posited and verified OCB as a sustainable contributor to organizational practices and outcomes [12], as well as benefiting the individuals who perform it [13]. On the dark side, some have suggested that OCB might have some unfortunate negative effects [14]. To some extent, striving to maintain job tasks' everyday effectiveness, while continuing to assist and support others, can create excessive work stress that not only affects job satisfaction but also the quality of family relationships [9]. Trougakos et al. [8] hypothesized that OCB would consume individual resources and, in the case of resource depletion, individuals should reduce their OCB to maintain task performance. This study will integrate the positive and negative aspects of OCB.
A great deal of research focuses on the causes of OCB. For example, corporate social responsibility, which has gained increased attention in line with the emergence of sustainable development [15][16][17][18][19], can positively affect employee OCB [20]. For a long time, there have been two main value orientations considered to underpin OCB: Volunteerism and utilitarianism [21]. According to the research on the value orientation of volunteerism, OCB is the positive behavior that individuals display voluntarily for the benefit of others, or the organization, beyond the call of duty [22]. It has been portrayed as a kind of voluntary behavior driven by personal values and internal motivation [23]. According to the research on the value orientation of utilitarianism, OCB is the trading behavior displayed by individuals under the norm of reciprocity to obtain more returns or expected returns [22]. It has been portrayed as a kind of self-interested behavior driven by external motivation [24]. Penner et al. [25] proposed that OCB is also a proactive behavior, which means employees are likely to choose to engage in OCB to satisfy their motives, and a recent study has explored the relationship between responsible leadership and OCB for the environment via employees' autonomous motivation and external motivation [26]. Thus, the current research chose two motives that account for OCB, representing the two value orientations underpinning OCB. Specifically, this study chose organizational concern (OC) motives, representing volunteerism, and impression management (IM) motives, representing utilitarianism [27]. OC motives are related to intrinsic motivation, while IM motives are related to extrinsic motivation. Although scholars have begun to study the consequences of OCB motives, they have mostly focused on the actual OCB levels [28,29]. Limited evidence has been provided on the effects of OCB motives on actors and resource loss. By integrating self-determination theory [30] with the conservation of resource (COR) theory [31], the current research studies the effects of two motives (OC motives and IM motives) of OCB on actors, and investigates the positive and negative aspects of OCB.
This study aims to examine whether OC motives and IM motives behind employees' OCB are differently associated with their citizenship fatigue and their subsequent thriving at work and whether task performance moderates these relationships. By testing these ideas in a multi-wave empirical study, this study makes several contributions. First, this study contributes to the OCB literature by providing a better understanding of the positive and negative effects of OCB motives from a resource-based perspective. By integrating self-determination theory [30] with COR theory [31], this study identifies the different effects of OC motives and IM motives on citizenship fatigue, which respond to the call to investigate the neutral and dark aspects of OCB [32]. Second, this study extends the COR theory by introducing OC motives and IM motives as two novel factors that may influence employees' resource loss. Third, this study contributes to the OCB literature by identifying task performance as a key boundary condition of the relationship between OCB motives and citizenship fatigue. As task performance serves as the outcome in most previous studies, this research also advances the task performance literature by focusing on the moderating role of task performance on the effects of OCB motives.
The remainder of this paper is organized as follows. Section 2 develops the hypotheses on the linkage between OC motives, IM motives, citizenship fatigue, thriving at work, and task performance. Section 3 introduces the methods and data. Section 4 presents the results. Conclusions and discussion are presented in Section 5.

Organizational Citizenship Behavior (OCB) Motives and Citizenship Fatigue
OCB refers to voluntary employee behavior that is discretionary, i.e., not directly rewarded by a formal system, and can benefit the organization [10]. As previously stated, there are two main value orientations underpinning OCB: Volunteerism and utilitarianism [21]. OCB is also a proactive behavior, which means that employees are likely to choose to engage in OCB to satisfy their motives. Thus, the current research chose two motives, representing the two value orientations underpinning OCB. Specifically, this study chose OC motives, representing volunteerism, and IM motives, representing utilitarianism [27]. OC motives refer to the desire to be helpful and involved in the organization, and IM motives refer to the desire to manage impressions and be looked at positively [29]. Citizenship fatigue refers to the degree to which individuals feel drained, worn out, or tired due to engaging in OCBs [33], which is strongly associated with OCB and other work outcomes. Based on self-determination theory, this study argues that the two OCB motives will have different effects on actors' citizenship fatigue.
Self-determination theory differentiates between intrinsic motivation and extrinsic motivation, positing that different types of motivation should have functionally different consequences and concomitants [34]. Intrinsic motivation is defined as a natural inclination toward spontaneous interest and autonomous motivation, which represents a principal source of enjoyment and vitality throughout life [35]. Extrinsic motivation describes the desire to achieve separable outcomes and is thus contrary to intrinsic motivation, which focuses on the inherent satisfaction. Comparisons between internal motivation and externally controlled motivation typically reveal that the former has more excitement and interest, which will manifest as heightened vitality and general well-being [36]. For example, employees who finish daily work because, internally, they enjoy their jobs are motivated intrinsically, while those who have to finish work because they are adhering to the control of supervisor or reality are extrinsically motivated. The internal motivation, which involves enjoyment and autonomy, is likely to have a better outcome, while the external motivation, which involves instrumentalities and external regulation, may lead to poorer outcomes.
Klotz et al. [37] suggest that when employees intrinsically enjoy going the extra mile, they are less likely to feel citizenship fatigue. Because OC motives are based on an internal desire to help the organization with which the actor identifies and in which the actor takes pride [29], intrinsic motivation is typically maintained because such motives satisfy competence and autonomy needs [38]. When employees perform OCB driven by OC motives, combined with enjoyment and volunteerism, they will not suffer citizenship fatigue. Thus, this study argues that OC motives will result in the depletion of citizenship fatigue owing to its associated autonomous motives, volunteerism, and enjoyment. Thus, this study hypothesizes that OC motives will be negatively related to citizenship fatigue: Hypothesis 1a. OC motives will be negatively related to citizenship fatigue.
Bolino [39] has argued that, in some cases, individuals engaging in OCB is a form of ingratiation and impression management. IM motives underlying OCB focus on a desire to sustain positive images and avoid negative images. Impression management requires some forms of modification and monitoring to attain a positive image, which suggests that impression management is a process of self-regulation in nature and will consume self-regulatory resources [40]. However, when self-regulatory resources are depleted, employees will become less effective in social or normative ways, especially when IM motives run counter to employees' tendencies [41]. Further, the process of self-regulation within IM motives derives more from extrinsic motivation and involves instrumentalities rather than enjoyment [38], and according to Spreitzer and Porath [42], when employees are intrinsically motivated and their efforts are volitional, energy is depleted slower compared to that when behaviors are imposed and instrumental. In other words, employees with IM motives, who are controlled by external forces, deplete more energy or resources [37] while employees with OC motives can perform better on Sustainability 2020, 12, 2231 4 of 17 subsequent self-control activities (without feeling anxious, tired, or worn out). Thus, this study argues that when employees engage in IM motives they will feel worn out and subsequently suffer citizenship fatigue: Hypothesis 1b. IM motives will be positively related to citizenship fatigue.

The Mediating Role of Citizenship Fatigue
Thriving at work refers to a psychological state in which employees experience a sense of learning and vitality during their working time [5]. Thriving at work as a "factor of human sustainability" typically matters in today's organizations and work environments, because employees have to deal with protean work and simultaneously struggle for high performance [43]. Spreitzer et al. [44] suggested that thriving composed of two dimensions: The sense of vitality and learning. Drawing on self-determination theory, Spreitzer and Porath [42] suggest that when employees are intrinsically motivated, behaviors are less effortful and vitality increases; and when employees are compelled for some instrumental reasons, vitality decreases. Furthermore, when employees are more responsible for the organization and more likely to go beyond the boundaries of their focused work responsibilities, they will experience more thriving at work [44]. Thus, this study argues that OC motives are positively related to employees' thriving at work, while IM motives are negatively related to thriving. This study supposes that the relationships between the two motives and thriving are mediated by citizenship fatigue.
The origin of citizenship fatigue is rooted in research that has sought to develop a more complete understanding of what happens when going out of one's way. Citizenship fatigue refers to the degree to which individuals feel drained, worn out, or tired due to engaging in citizenship behaviors. And citizenship fatigue is different from felt stress, role overload, and burnout. For instance, felt stress captures the sense that one's work is stressful which is associated with job tasks, and burnout reflects a general syndrome of emotional exhaustion and depersonalization, which can influence many facets of jobs [33]. Employees suffering from citizenship fatigue may be more likely to attribute this to their engagement in OCBs and, therefore, decrease future acts of OCB as a response to citizenship fatigue [33].
According to COR, when employees engage in resource loss at work, they will experience strain in the form of depression, feeling worn out, and psychological outcomes [45], and they will avoid such behaviors and further resource losses since loss can have a negative impact [46]. In the context of this study, when employees experience resource losses (manifested via citizenship fatigue), they are more likely to avoid resource investment to reserve resources. However, research has indicated that individuals need to be active and agentic in work to gain thriving at work [44]. Thus, employees who feel citizenship fatigue may experience less thriving at work because they invest less effort in citizenship work which has the potential to enhance one's vitality and knowledge. In line with this view, scholars have suggested that when employees lose resources, investment becomes more difficult (i.e., a resource loss spiral) [47].
Further, one stream of research has examined concepts like being worn out or depression that appear to share a similar domain space, which means that these concepts share general syndromes in all aspects. Employees suffering from citizenship fatigue will feel frustrated and worn out and have a low level of psychological capital [48]. Paterson et al. [1] asserted that psychological capital will have a positive effect on thriving at work. Thus, this study argues that citizenship fatigue will subsequently have a negative effect on employees' thriving at work.
This study also argues that OC motives derive from an internal desire and intrinsic motivation to help the organization [29], while IM motives focus on extrinsic motivation to control the public image. Through enjoyment and volunteerism, this study argues that OC motives will result in the depletion of citizenship fatigue and that, due to the depletion of self-regulation resources through a form of instrumentalities rather enjoyment, employees with IM motives will feel worn out and subsequently suffer citizenship fatigue. Based on what is discussed above, this study proposes that citizenship Sustainability 2020, 12, 2231 5 of 17 fatigue will mediate both the positive and negative relationship between OC motives, IM motives, and thriving at work: Hypothesis 2a. Citizenship fatigue will mediate the positive relationship between OC motives and thriving at work. Hypothesis 2b. Citizenship fatigue will mediate the negative relationship between IM motives and thriving at work.

The Moderating Role of Task Performance
Thus far, this study has argued that OC motives may increase employees' thriving at work through decreasing their citizenship fatigue, while IM motives influence thriving at work and citizenship fatigue oppositely. As self-determination theory suggests that the satisfaction of basic needs depends on the extent to which contextual factors support individuals' basic needs satisfaction [30], this study further proposes that the effects of OCB motives on citizenship fatigue may be moderated by task performance. Task performance refers to the supervisor's appraisal and evaluation of their subordinates' task performance [49]. This study suggests that when employees receive high task performance ratings from their supervisors, such context may amplify both the negative effect of OC motives and the positive effect of IM motives on citizenship fatigue.
Regarding OC motives, evidence has indicated that performance appraisal can meet employees' competence need, which may, in turn, enhance their intrinsic motivation [50]. Similarly, research has shown that performance feedback may contribute to intrinsic motivation through increasing individuals' perceived competence [51]. Given that employees with OC motives are likely to feel enjoyment from engaging in OCB when they can derive more intrinsic motivations from supervisors' task performance ratings, their enjoyment can be enhanced and engaging in OCB may become easier, both of which may result in lower citizenship fatigue [37]. Thus, this study argues that, when task performance is high, employees engaging in OCB with OC motives are likely to feel less citizenship fatigue.
The COR theory can also help to understand the moderating role of task performance in the OC motives-citizenship fatigue relationship. Research has indicated that high-performance ratings may improve employees' resources through enhancing their feelings of self-worth and achievements [52]. These resources can supplement the resource loss caused by engaging in OCB among employees with OC motives. This is in line with the COR theory which suggests that resource loss can be buffered through obtaining external resources from the environment [53]. Therefore, given the potential to increase employees' enjoyment and resources, this study proposes that when employees with OC motives receive a high-level task performance rating from their supervisors, their level of citizenship fatigue will be decreased.

Hypothesis 3a.
Task performance can moderate the negative relationship between OC motives and citizenship fatigue, such that the negative relationship will be stronger in the presence of higher (vs. lower) task performance.
However, employees with IM motives pay more attention to environmental cues which can guide them to regulate their behaviors to maintain a good image, instead of to contribute to their organizations [28]. As such, when supervisors give high task performance ratings to their subordinates, those with IM motives may use this as a cue of future impression management. Research has indicated that employees who receive high task performance ratings are likely to gain high-performance appraisal such that supervisors may perceive these employees as outstanding [54]. Such high-level performance appraisals may promote the standards or goals for employees with IM motives to manage their impressions, which in another sense limits the employees' impression management such that they must maintain or improve the current image and avoid falling below the standard. Thus, according to the self-determination theory, supervisors' high task performance ratings may further undermine the sense Sustainability 2020, 12, 2231 6 of 17 of ownership of behaviors (i.e., autonomy needs) among employees with IM motives [34]. Research has indicated that a decreased satisfaction of autonomy needs may associate with an increase of external motivations [55], which forces employees to engage in behaviors without inherent satisfaction of the behavior itself [30]. Thus, when employees with IM motives receive high task performance ratings from their supervisors, they may experience more citizenship fatigue because they need to achieve higher goals through engaging in OCB which is not inherently enjoyable and easy to start.
Besides, employees engaging in impression management need to consume resources to regulate their behaviors [40]. As discussed above, a high-level task performance rating may increase the standard of impression management, which may require more resources to regulate employees' behaviors. Thus, employees with IM motives may experience more citizenship fatigue when they receive high task performance ratings because they need to invest more self-regulatory resources to engage in OCB, which is instrumental to build positive images. Taken together, this study proposes the following hypothesis: Hypothesis 3b. Task performance will moderate the positive relationship between IM motives and citizenship fatigue, such that the positive relationship will be stronger in the presence of higher (vs. lower) task performance ratings.
These arguments suggest an integrated model, in which OC motives have positive indirect effects whereas IM motives have negative indirect effects on thriving at work via citizenship fatigue. Moreover, this study suggests that task performance moderates the effects of OCB motives on citizenship fatigue. Accordingly, this study proposes that task performance also moderates the strength of the mediating mechanism for citizenship fatigue in the relationship between OCB motives and thriving at work-a moderated mediation model. Because stronger linkages of OC motives with citizenship fatigue when employees receive a high rating of task performance are expected, this study predicts that the mediating effects of citizenship fatigue on the relationship between OC motives and thriving at work also will be stronger among these employees. Similarly, this study proposes that the mediating effects of citizenship fatigue on the relationship between IM motives and thriving at work will be stronger among employees who receive a high task performance rating. Thus, this study proposes the following hypotheses: Hypothesis 4a. Task performance will moderate the positive indirect effect of OC motives on thriving at work via citizenship fatigue, such that the positive indirect effect will be stronger in the presence of higher (vs. lower) task performance ratings.
Hypothesis 4b. Task performance will moderate the negative indirect effect of IM motives on thriving at work via citizenship fatigue, such that the negative indirect effect will be stronger in the presence of higher (vs. lower) task performance ratings.
Based on the above hypotheses, this study proposes a theoretical model, which is presented in Figure 1. Besides, employees engaging in impression management need to consume resources to regulate their behaviors [40]. As discussed above, a high-level task performance rating may increase the standard of impression management, which may require more resources to regulate employees' behaviors. Thus, employees with IM motives may experience more citizenship fatigue when they receive high task performance ratings because they need to invest more self-regulatory resources to engage in OCB, which is instrumental to build positive images. Taken together, this study proposes the following hypothesis: Hypothesis 3b. Task performance will moderate the positive relationship between IM motives and citizenship fatigue, such that the positive relationship will be stronger in the presence of higher (vs. lower) task performance ratings.
These arguments suggest an integrated model, in which OC motives have positive indirect effects whereas IM motives have negative indirect effects on thriving at work via citizenship fatigue. Moreover, this study suggests that task performance moderates the effects of OCB motives on citizenship fatigue. Accordingly, this study proposes that task performance also moderates the strength of the mediating mechanism for citizenship fatigue in the relationship between OCB motives and thriving at work-a moderated mediation model. Because stronger linkages of OC motives with citizenship fatigue when employees receive a high rating of task performance are expected, this study predicts that the mediating effects of citizenship fatigue on the relationship between OC motives and thriving at work also will be stronger among these employees. Similarly, this study proposes that the mediating effects of citizenship fatigue on the relationship between IM motives and thriving at work will be stronger among employees who receive a high task performance rating. Thus, this study proposes the following hypotheses: Hypothesis 4a. Task performance will moderate the positive indirect effect of OC motives on thriving at work via citizenship fatigue, such that the positive indirect effect will be stronger in the presence of higher (vs. lower) task performance ratings.
Hypothesis 4b. Task performance will moderate the negative indirect effect of IM motives on thriving at work via citizenship fatigue, such that the negative indirect effect will be stronger in the presence of higher (vs. lower) task performance ratings.
Based on the above hypotheses, this study proposes a theoretical model, which is presented in Figure 1.

Sample and Procedures
This study was conducted by convenience sampling in 40 hotel companies in China, and paper questionnaire surveys were conducted by visiting these companies directly. To alleviate common method variance concerns, this study collected three rounds of data with a 1-month time lag [56].

Sample and Procedures
This study was conducted by convenience sampling in 40 hotel companies in China, and paper questionnaire surveys were conducted by visiting these companies directly. To alleviate common method variance concerns, this study collected three rounds of data with a 1-month time lag [56]. This research design is widely applied in the research, which studies the moderated mediation model [57]. With the assistance of the companies' human resource departments, this study invited employees and their direct supervisors to complete the paper questionnaire. This study ensured that all invited participants understood that participation was voluntary and informed them of the manipulation procedures of the survey. At Time 1, of 815 invited employees supervised by 160 supervisors, 682 employees rated their own OC motives, IM motives, age, gender, tenure, and education, and 141 supervisors rated their employees' task performance. At Time 2, one month after

Measures
This study translated the survey from English to Chinese to ensure the appropriateness of the content and a high degree of accuracy by using the conventional translation and back-translation procedures [58]. All measures used a five-point Likert scale ranging from 1 ("strongly disagree") to 5 ("strongly agree").
OC motives. This study used the 10-item scale developed by Rioux and Penner [27] to measure OC motives (α = 0.92). This study asked participants to rate the extent to which their OCBs were motivated by various reasons, e.g., "Because I want to understand how the organization works." IM motives. This study used Rioux and Penner's [27] 10-item scale to measure IM motives (α = 0.91). This study asked participants to rate the extent to which their OCB was motivated by various reasons, such as, "To avoid looking bad in front of others." Task performance. This study assessed task performance (α = 0.92) with a five-item scale adapted from Ingold et al. [49]. A sample item was, "The employee plans and organizes to achieve objectives of the job." Citizenship fatigue. This study used a seven-item scale developed by Bolino et al. [33] to measure employee citizenship fatigue (α = 0.95). A sample item was, "Volunteering to take on extra tasks and assignments at work has left me feeling drained." Thriving at work. This study used Porath et al.'s [5] 10-item scale to measure employee thriving at work (α = 0.84). Sample items included, "I see myself continually improving" and "I am looking forward to each new day." Control variables. This study measured gender (0 = male, 1 = female) and education degree as control variables [59].

Data Analysis
Data were analyzed using the SPSS, Amos, and Mplus. First, frequency analysis and descriptive statistics analysis were conducted, and correlation analysis was conducted to identify the relationship and direction among major variables using SPSS. Second, a confirmatory factor analysis (CFA) was conducted, using Amos 21, to assess the discriminant validity of the main variables. Finally, this study tested the hypotheses using Mplus 7 and tested indirect and conditional indirect effects using the Monte Carlo resampling method.

Preliminary Analyses
Before testing the hypotheses, this study conducted a confirmatory factor analysis (CFA), using Amos 21, to assess the discriminant validity of the OC motives, IM motives, task performance, citizenship fatigue, and thriving at work. Based on previous research [60], this study adopted item parceling. This study used parcels as indicators, because parcels are more reliable, lead to more equal and smaller distances between values, and can also increase normality in distributions. While too many items as indicators would result in a high number of parameters to be estimated [61]. This study created two facet-based parcels (learning and vitality) for thriving at work [62] and three parcels each for OC motives and IM motives, respectively. Because the two measures did not have facets, this study adopted an unplanned aggregation strategy for item parceling [61]. The five task performance items and the seven citizenship fatigue items were not parceled. The results are shown in Table 2. Note. OCM = organizational concern motives, IMM = impression management motives, TP = task performance, CF = citizenship fatigue, WT = thriving at work, RMSEA = root mean square error of approximation, SRMR = standardized root mean square residual, CFI = comparative fit index.
Sustainability 2020, 12, 2231 9 of 17 As shown in Table 2, the five-factor model had the best fit (χ 2 (160) = 386.96, p < 0.01, RMSEA = 0.06, SRMR = 0.04, CFI = 0.96) over the four-factor model, in which OC motives and IM motives were combined (∆χ 2 /(4) = 489.54, p < 0.01), and better than a series of alternative models. Thus, this study reserved the five-factor nested model and continued to test the proposed hypotheses. Although the data derived from different sources, this study performed Harman's one-factor test [56] to check the common method variance. The factor explained 20.57% of the variance; thus, this research did not have serious common method variance. Table 3 shows the descriptive statistics, reliabilities, and correlations of variables. As shown in Table 3, OC motives were negatively related to citizenship fatigue (r = −0.11, p < 0.05) preliminarily supporting H1a; IM motives were positively related to citizenship fatigue (r = 0.38, p < 0.01), preliminarily supporting H1b.

Tests of the Hypotheses
This study tested the hypotheses using Mplus 7. The results are shown in Table 4. OC motives were negatively related to citizenship fatigue (β = -0.25, p < 0.001), supporting H1a. Besides, IM motives were positively related to citizenship fatigue (β = 0.37, p < 0.001), supporting H1b. This study tested H3a and H3b by examining the interactive effects of OC motives and task performance as well as IM motives and task performance on citizenship fatigue. As shown in Table 4, the interaction of IM motives and task performance was significantly related to citizenship fatigue (β = 0.16, p < 0.05). A simple slope test as reported in Figure 2 indicates that there was a stronger positive relationship between IM motives and citizenship fatigue among employees who received high task performance rating (simple slope = 0.50, p < 0.001) than among those who received low task performance rating (simple slope = 0.24, p < 0.01). Thus, H3b was supported. However, the interaction of OC motives and task performance was not significant (β = -0.04, n.s.); thus, H3a was not supported, and H4a was not supported either. positive relationship between IM motives and citizenship fatigue among employees who received high task performance rating (simple slope = 0.50, p < 0.001) than among those who received low task performance rating (simple slope = 0.24, p < 0.01). Thus, H3b was supported. However, the interaction of OC motives and task performance was not significant (β = -0.04, n.s.); thus, H3a was not supported, and H4a was not supported either. This study tested indirect and conditional indirect effects using the Monte Carlo resampling method [63]. Each confidence interval was based on 20,000 resamplings [64]. As shown in Table 5, this study found that the indirect effect for OC motives on thriving at work via citizenship fatigue was 0.04 (95% confidence interval, CI [0.02, 0.06]). The indirect effect for IM motives on thriving at work via citizenship fatigue was -0.05 (95% confidence interval, CI [-0.08, -0.03]). These results supported H2a and H2b. The indirect effect of IM motives on thriving at work was significant when task performance was high (indirect effect = -0.07, SE = 0.02, CI [-0.11, -0.04]) and significant when task performance was low (indirect effect = -0.04, SE = 0.01, CI [-0.06, -0.02]), and the difference was significant (effect = -0.04, SE = 0.02, CI [-0.07, -0.00]). Thus, the results did support H4b.  This study tested indirect and conditional indirect effects using the Monte Carlo resampling method [63]. Each confidence interval was based on 20,000 resamplings [64]. As shown in Table 5, this study found that the indirect effect for OC motives on thriving at work via citizenship fatigue was 0.04 (95% confidence interval, CI [0.02, 0.06]). The indirect effect for IM motives on thriving at work via citizenship fatigue was -0.05 (95% confidence interval, CI [-0.08, -0.03]). These results supported H2a and H2b. The indirect effect of IM motives on thriving at work was significant when task performance was high (indirect effect = -0.07, SE = 0.02, CI [-0.11, -0.04]) and significant when task performance was low (indirect effect = -0.04, SE = 0.01, CI [-0.06, -0.02]), and the difference was significant (effect = -0.04, SE = 0.02, CI [-0.07, -0.00]). Thus, the results did support H4b.  Note. N = 349. CI = confidence interval. a Confidence intervals were calculated using the Monte Carlo method. Each confidence interval was based on 20,000 resamplings.

Conclusions
Using a three-wave survey, this study has proposed and empirically tested a moderated mediation model linking two OCB motives with thriving at work via citizenship fatigue, and the moderating role of task performance on these effects. The findings revealed that, while OC motives enhance employees' thriving at work through reducing their citizenship fatigue, IM motives undermine employees' thriving at work through increasing their citizenship fatigue. This suggests that different motives underlying OCB will affect differently on employee thriving at work. When employees enact OCB under OC motives, which combines with enjoyment and volunteerism [29], they will consume less resources, and they will suffer less fatigue and further maintain vitality and learning at work. In contrast, when employees enact OCB driven by IM motives, which is often viewed as extrinsic motivation and involves instrumentalities rather than enjoyment [38], they will consume more self-regulatory resources and feel worn out. As a factor of human sustainability and sustainable performance, employee thriving at work contributes to organizational sustainability [1][2][3][4]. The findings of this study increase our understanding of the factors that foster thriving and sustainable performance.
Further, when employees enacting OCB with IM motives received high task performance ratings from their supervisor, they experienced more citizenship fatigue and subsequently less thriving at work. This reveals that employees who take advantage of organizational citizenship behavior to make good impressions on their supervisor would experience increased fatigue when they receive high task performance ratings. OCB is often viewed as a sustainable contributor to organizational outcomes [12], as well as benefiting the actors [13]. OCB is positively related to sustainable performance [11]. However, the dark side of OCB cannot be neglected [32]. We distinguished motivations behind OCB as previous studies do [26,29], and examined their different effects on thriving. Especially, for high performers with IM motives, they may invest more effort to regulate their behaviors to avoid a discrepancy between their future image and their current image, which will lead to negative outcomes. This research advances the task performance and OCB literature by highlighting the potential dark sides of high task performance ratings and OCB.
The findings of this study increase our understanding of the factors that foster thriving and sustainable performance. Our study seeks to draw the attention of managers regarding the importance of OCB motives, task performance appraisal in promoting thriving among employees, which in turn enhances the sustainable development of the organization.

Theoretical Contributions
The current research makes several theoretical contributions. First, this study contributes to the OCB literature by identifying the positive and negative effects of OCB motives from a resource-based perspective. Although scholars have begun to study the consequences of OCB motives, they have mostly focused on actual OCB levels [28,29]. Limited evidence has been provided on the effects of OCB motives on actors and resource loss. By integrating self-determination theory with COR theory, this study examined and found that employees engaging OCB with OC motives would experience less citizenship fatigue while those with IM motives would experience more citizenship fatigue. By doing so, this study also responds to the call of investigating the neutral and dark aspects of OCB [32].
Second, this study also extends the COR theory by introducing OC motives and IM motives as novel factors that may influence the extent of individuals' resource loss. Employees with OC motives are more willing to engage in OCB because doing so can enhance their sense of belonging to the organization [65]. According to the self-determination theory, activities satisfying individuals' relatedness needs may activate their intrinsic motivation, which makes them more willing and able to complete this activity [38]. Although employees inevitably need to invest resources in their work [46], engaging in OCB with more OC motives may decrease their levels of resource loss. In contrast, employees who engage in OCB with IM motives focus on external factors such as supervisors' evaluations [39]. Such employees may devote more effort to take on extra work because they are not interested in the work itself [66], and thereby they will experience more resource loss. The COR theory has primarily been applied to explain the effects of stress and strain, which are the main causes of individuals' resource loss [45].
Third, this study contributes to the OCB literature by identifying task performance as a key boundary condition in determining the effects of OCB motives on citizenship fatigue. Previous studies have mainly focused on the direct effects of OCB motives or interactions between different OCB motives on individuals' levels of OCB [13,17,47]. However, factors that may influence the strength of the effects of OCB motives have been neglected. This research suggests that for employees with IM motives who are inherently not interested in citizenship work, they may consume more self-regulatory resources when supervisors give them high task performance ratings. This is because becoming a high performer in the eyes of supervisors improves the goal they need to achieve through self-regulation, which in turn exacerbates the resource loss. However, task performance had no moderating effect on the negative relationship between OC motives and citizenship fatigue. This study provided two possible reasons for this unsupported moderating effect of task performance. First, self-determination theory proposes that contextual factors such as feedback or rewards, which lead to individuals' feelings of competence, can enhance the effect of intrinsic motivation [38]. This study argues that high task performance ratings are likely to foster a feeling of competence, thus enhancing the effect of employees' intrinsic motivation [50]. However, employees who voluntarily engage in OC motives often already have a high awareness of their competence [67] and may be less influenced by external competence appraisal. This may help to explain why the moderating role of task performance between OC motives and citizenship fatigue was not found to be significant. Second, the COR theory suggests that the benefits of resource gain can be more salient when employees need them [31]. For employees with OC motives, this study suggests that their citizenship fatigue will be lower than those with IM motives since they engage in OCB for enjoyment instead of being forced to engage in OCB with an instrumental goal. Thus, task performance, as one resource, may provide limited benefits to employees with OC motives as they are not in a situation where resources are particularly needed.
Furthermore, this research also advances the task performance literature by highlighting the potential dark sides of high task performance ratings. Compared with previous studies that examined task performance as an outcome of OCB [28], this study examined how task performance strengthens the citizenship fatigue of employees who engage in OCB with IM motives. The findings of this research showed that employees who take advantage of organizational citizenship behavior to make good impressions on their supervisor would experience increased citizenship fatigue when they receive high task performance ratings. As employees who receive high task performance ratings are also likely to gain high-performance appraisals such as outstanding employees [54], they may invest more effort to regulate their behaviors to avoid a discrepancy between their future image and their current image (i.e., a high performer) [40]. In other words, high task performance ratings promote employees' latitude of images that they need to maintain in front of their supervisors. Although giving high-performance appraisals enables those who perform OCB with IM motives to achieve their goals [28], this study suggests that it may also lead to higher citizenship fatigue and subsequently lower thriving at work for them.
Finally, this research advances the thriving literature by examining and integrating different effects of OCB motives on thriving at work. As an important factor of human sustainability, employee thriving has recently drawn much attention [1][2][3][4]. Some studies posited that thriving employees are more likely to engage in OCB [6,7]. However, the impact of employee OCB on employee thriving is not clear, which can affect not only employee career development but also organization sustainability. This research argues and examines that OC-motivated OCB positively affects thriving, while IM-motivated OCB negatively affects thriving. Thus, this study advances the reciprocal cycle between OCB and thriving: Thriving is positively related to OCB, and only OCB driven by OC motives is positively related to thriving.

Practical Implications
The present research also has several practical implications. First, as shown by these findings, OC motives enhance thriving at work through reducing citizenship fatigue while IM motives undermine thriving at work through inducing citizenship fatigue. Thriving at work, which reflects human sustainability and sustainable conditions, should be of concern. To improve employees' thriving at work, managers should look beyond the surface appearance of OCB performance to get to the core of why their subordinates are performing OCB. Organizations should cultivate employees' feelings of organizational concern and decrease their opportunistic tendency. Second, this research confirms that high task performance ratings will be harmful to employees who engage in OCB with IM motives. Thus, managers are suggested to pay attention to employees' motives when they assess their subordinates' task performance. For those employees who view citizenship work as instrumental, they are "good actors" who are inherently not interested in and do not enjoy the citizenship work [39]. Rating them highly on their task performance may force them to engage in a higher level of OCB to maintain an image of a high performer, which in turn results in higher citizenship fatigue and lower thriving at work. The development of an organization is as important as the physical and mental health of its Sustainability 2020, 12, 2231 13 of 17 employees. Although employees with IM motives can contribute to organizations to engage in OCB in the short-term, the resulting high level of citizenship fatigue may discourage these employees from investing effort in their future work.

Limitations and Future Directions
Although the current research reveals several implications, there are still some limitations. First, although this study collected data at three time points, the potential for reverse causality cannot be completely ruled out. Future studies may conduct laboratory experiments to provide support for the causal relationships in this model. Besides, although this study collected data from two different sources-supervisors and subordinates-findings on the relationships between employee-rated variables may be influenced by common method bias. As recommended by Podsakoff et al. [56], this study tested the potential influence of common method bias and results showed that it would not be a major concern. Nevertheless, future research may replicate the present findings using data collected from multiple sources.
Second, considering citizenship fatigue and thriving at work may vary from day to day, future studies should test this model again using the experience sampling method [68]. For example, participants can rate their levels of OC motives and IM motives in the afternoon and rate citizenship fatigue and thriving at work at the end of the day. Future studies can also examine the effects of thriving at work on the next day's levels of OC motives and IM motives.
Third, although Rioux and Penner [27] identified three different OCB motives, this study only focuses on OC motives and IM motives and does not cover the prosocial value motives (describe a desire to help and connect with others) which may have similar effects as OC motives. However, future research still needs to examine the three motives simultaneously to see if there are different effects among them. As recent research has begun to discuss OCB motives through identifying whether employees' helping behaviors are volunteered or pressured by the organization (i.e., autonomous motivation vs. controlled motivation) [69], future research may build on this research to examine the difference between these two motives. In addition to resource loss, future research can also explain the different effects of OCB motives by drawing from other theories.
A fourth limitation is that this study was conducted among a specific group of employees, namely hotel workers. The convenience sampling strategy in this study limited the generalizability of the findings to the general working population. Future studies may investigate whether the results can be generalized to different sectors.
Finally, we tested hypotheses using a sample from China, which has a collectivistic culture [70]. Compared with employees in individualistic cultures, employees in collectivistic cultures are more likely to act in the interest of working groups and organizations [71]. This would suggest that the positive effect of organizational concern OCB motives we observed may be weaker in individualistic cultures. In contrast, employees in individualistic cultures will regulate their investments more with their direct benefits and focus more on the leader [72]. Thus, the negative effect of impression management OCB motives we observed may be stronger in individualistic cultures.

Conflicts of Interest:
The authors declare no conflict of interest.