In the changeable information age, many corporations have focused more prominently on the use of knowledge (Liu et al., 2018; Ganguly et al., 2019). Knowledge sharing is the key to knowledge management (Wang and Noe, 2010; Lei et al., 2019), the main problem of current knowledge management is how to facilitate information transmission among individuals and reduce knowledge hiding (King and Marks, 2008; Yao et al., 2020). This is crucial because knowledge cannot be fully utilized, which may affect the performance of the organization (Carmeli et al., 2011; Zhang et al., 2021b). Connelly et al. (2012) define knowledge hiding as “individuals intentionally conceal or hide the knowledge requested by others”. That is, knowledge hiding can be deemed as a strategy for employees to form a competitive advantage and maximize individual benefits in an organization. Importantly, in highly competitive environments, employees' knowledge hiding behavior will not only have a potential negative impact on employees themselves but also be a major threat to the development of contemporary enterprises, which may lead to massive economic losses to the organization (Černe et al., 2014; Connelly et al., 2019; Zhang et al., 2022). Despite the importance of knowledge hiding, there is little literature on the subject. Based on the significant benefits of knowledge, enterprises will pay more attention to the acquisition and effective use of information. Researchers have mainly categorized knowledge hiding in three elements. Connelly and Zweig (2015) indicates that knowledge hiding is individuals intentionally hiding or concealing knowledge requested by others and proves that knowledge hiding consists of three independent but related elements: i) Rationalized hiding, i.e., the concealer justifies, by implying that the requester is unable to provide the requested knowledge; ii) Playing dumb, i.e., the concealer pretends not to know the relevant information or knowledge; iii) Evasive hiding, i.e., the concealer provides incorrect information or knowledge.

Overqualification stems from the concept of underemployment and is a sub-dimension of it (Feldman et al., 2002). Overqualification is divided into objective and subjective. Objective overqualification means that the knowledge, skills, and abilities (KSAs) that an individual possesses more than the basic requirements and work experience of the job position (Maynard et al., 2006; Erdogan et al., 2011). It is determined by contrasting whether the individuals' qualifications are in line with the work label (Martinez et al., 2014; Zhang et al., 2016; Sesen and Ertan, 2019). This is an objective fact, assessed fairly and impartially by an observer who is not subject to external constraints (Maltarich et al., 2011; Sesen and Ertan, 2019) and only used to understand the psychological experiences of employees who have overqualifications (Erdogan et al., 2011; Chu et al., 2021). Subjective overqualification is described as “the degree to which individuals perceive their qualifications to match the position requirements” (Maynard et al., 2006). The perceived overqualification is related to individuals' personal opinions about them (Sesen and Ertan, 2019), within the category of subjective evaluation. Studies show that individuals with subjective overqualification are more susceptible to the mismatch between their surroundings and their eligibility (Fine, 2007; Luksyte et al., 2011; Chu et al., 2021).

This paper examines perceived overqualification and its effect on knowledge management, and therefore emphatically discusses the concept of the perceived overqualification. Previous studies found positive and negative regarding the consequences of the perceived overqualification, and maybe the individuals can treat and respond to their views of the perceived overqualification from two different points. Different individual abilities generate different effects on their work performance (Zhang et al., 2021c). Firstly, they may feel that their capacity is underutilized. This psychological feeling may cause them to have negative emotions, which in turn change their positive attitude and correct behavior (Maynard et al., 2006; Erdogan and Bauer, 2009; Chu et al., 2021). Most studies often adopt these ideas, such as affected individuals may develop negative emotions and psychology (Peiró et al., 2012; Liu et al., 2015; Simon et al., 2019), reducing work pleasure and increase the willingness to leave (Erdogan et al., 2020; Wu and Chi, 2020).

Previous studies have stressed on work behavior under the influence of individuals' perceived overqualification with different conclusions. Most studies have argued that the perceived overqualification can adversely affect individuals' knowledge management behaviors, such as knowledge hiding (Khan et al., 2022; Li C. S. et al., 2022). Zutshi et al. (2021) believe that knowledge hiding is more correlated to negative emotions. Some researchers have also shown that perceived overqualification reduces knowledge-sharing behavior. Comparing knowledge hiding and knowledge sharing, deliberate attempts to hide information that another person needs is called knowledge hiding (Li C. S. et al., 2022). The researchers highlight the main difference between the two behaviors (sharing and hiding) may be their motive (Agarwal et al., 2021; Zhong et al., 2021; Khan et al., 2022). In prior studies, some scholars have proposed that the perceived overqualification of individuals was positively associated with knowledge management behavior of individuals in organizations. Employees perceived overqualification enhances their proactive work behavior (Erdogan et al., 2011; Zhang et al., 2016), and they may be involved in the work formulation actively (Maynard, 2011; Russell et al., 2016; Lin et al., 2017; Sesen and Ertan, 2019). Existing studies have confirmed that employees who perceived higher overqualification prefer to express their personal views in the organization to gain recognition. When individuals have the remaining KSAs in their work (At least in their self-perception), they may take a positive approach, i.e., they are willing to use the remaining KSAs to help colleagues (Li C. S. et al., 2022). Individuals with stronger KSAs often better understand, interpret, and use a variety of information (Earley, 2002; Earley and Peterson, 2004; Zhang Y. et al., 2020). For example, teams and organizations may request knowledge from the individuals who perceived overqualification by encouraging the others or leverage the KSAs of perceived overqualification individuals by having overqualified individuals guide more capable colleagues and impart their knowledge across the team (Thompson et al., 2013; Russell et al., 2016; Sikora et al., 2016). It enables individuals to obtain the satisfaction of self-worth, and the team or organization maximizes the benefits of individuals. Current empirical research on perceived excess of qualification and knowledge concealment is inadequate. We believe that the individuals who feel good about themselves will show their knowledge advantages and abilities to others in a positive way, so, according to the above literature review, we make the following hypothesis:

Psychological capital (PsyCap) is described as a developmental state of a person's positive psychology, including optimism, hope, resilience, and self-efficacy (Luthans et al., 2007; Avey et al., 2011), which can be established to improve their performance (Luthans, 2002; Luthans and Youssef, 2004; Luthans et al., 2007). The psychological capital appears to capture an individual's psychological abilities, containing four dimensions that all represent a positive assessment of a person's abilities. As an important psychological ability for individuals to undertake more demanding tasks (Parker and Collins, 2010), psychological capital is a primary component to study the relationship between the main variables (POQ and KH) studied in this paper. To some extent, the perceived overqualification is central to the formation of individual psychological capital (Gist and Mitchell, 1992; Den Hartog and Belschak, 2012). For example, when analyzing task requirements, individuals with higher qualifications may consider their tasks relatively easy and can be performed effortlessly, however, owing to possessing more resources (such as KSAs), individuals rather seek a wider range of tasks actively than instructions limited to upper managers, and they will better master additional tasks beyond their job requirements or responsibilities. In other words, individuals with surplus KSAs are more likely to perform challenging tasks and achieve these goals confidently, which leads to a higher assessment of their psychological capital. In a similar vein, Jung and Yoon (2015) believe that whether individuals can perform tasks within or outside their roles excellently depends on their psychological ability to a certain extent. Psychological ability will affect their subjective initiative and reduce the passive attitude of individuals in the organization. Therefore, psychological capital plays an important part in knowledge management, that is, individuals' optimism, hope, resilience, and self-efficacy, which provide psychological safety and psychological support for reducing the hidden behaviors of individuals' knowledge and enhancing other knowledge behaviors such as the sharing and application of individuals' KSAs.

Drawn from psychological resource theory, psychological capital is a high-order structure consistent with active organizational behavior (Luthans and Youssef, 2004), and existing research focuses on its impact on organizational management. Psychological capital is a basic concept of positive organizational behavior (Avey et al., 2009), which emphasizes motivational rather than negative factors. In this context, psychological capital promotes job performance and job creation that are conducive for individuals to control their emotions and cope with stress, and reduce their negative behaviors (Avey et al., 2009). Studies have shown that skill utilization is positively associated with self-esteem in the workplace (Aryee and Luk, 1996). In particular, individuals who perceive overqualification may simultaneously provide dynamic energy in the whole process, with their own excess KSAs, and actively help colleagues to control the adverse impact of the perceived overqualification in this positive way. Accordingly, based on capability perspective of positive organizational behavior theory, they will use redundant KSAs to help the team and other members of the organization, and then make more contributions to the team or organization. In this process, its KSAs are valued by the organization, which promotes positive self-evaluation, and then affects their self-efficacy (Lai, 2011; Luksyte et al., 2011; Vinayak et al., 2021), forming a favorable cycle between perceived overqualification, psychological capital, and individual knowledge management behavior.

While scholars focus on the importance of individual characteristics, behaviors, and abilities in the context of knowledge management, there are few precedents for psychological capital. As for the potential of psychological capital structure, it has not been fully tested in the existing literature (Zhang et al., 2021a). Indeed, there is rather little literature on the effects of the perceived overqualification on psychological capital. Self-determination theory (Ryan and Deci, 2000) sees the need for competence, relevance, and autonomy as fundamental to a person's mental health and innate motivation. Employees with the self-identified remaining KSAs are more likely to perform challenging tasks. Their qualifications and experience give them a sense of self-efficacy that allows them to make full use of their skills. They may have a better command of other tasks beyond their job requirements or responsibilities, and then meet the need for motivation and internal motivation to work, driving his hope, optimism and resilience formation, which will lead to a higher evaluation of his psychological capital. Therefore, given the importance of the perceived overqualification for knowledge management based on the theory of planned behavior, it is reasonable to predict that perceived overqualification may have a positive effect on individual psychological capital. Consequently, we recommend that:

Prior research has revealed the difference between information dissemination and knowledge hiding. Connelly et al. (2012) distinguished two kinds of knowledge management behaviors: knowledge sharing (KS) and knowledge hiding (KH). The sharing is “the act of spreading knowledge within an organization” and “the conscious act of a person who knows” (Ipe, 2003). The study focuses on double key sides of sharing: the frequency and the quality or usefulness (Soo et al., 2004; Swift and Virick, 2013; Gagné et al., 2019). Kim and Park (2017) argue that only knowledge can be managed efficiently through effective knowledge sharing.

Though information dissemination and knowledge hiding are usually seen as the contrary behavior, their motives are distinctive (most cases are irrelevant). In other words, they are relatively independent actions, and also vary with each individual (Gagné et al., 2019). Knowledge hiding is not entirely negative behavior and does not necessarily harm an individual or organization (Connelly and Zweig, 2015). It has been distinguished from many related but different behaviors, such as cheat (Webster et al., 2008). In the light of Connelly et al. (2012), people's knowledge hiding occurs more due to distrust, and this behavior may be influenced by their cognition of organizational and individual psychology. However, when colleagues recognize the occurrence of knowledge hiding behavior, a cycle of mistrust will occur (Akhtar et al., 2021).

According to the social cognitive theory, self-efficacy in psychological capital is the inner driving power for individual initiative. Whether or not a person is willing to do something outside of their job will affect whether or not they decide to take action and invest the effort and time (Hong et al., 2016). The individuals who perceived overqualification feel that they have the remaining KSAs, so they have enough confidence and motivation to help others in the organization or team members, answer their questions, avoid knowledge hiding, and perform work responsibilities beyond their prescribed roles. Individuals with higher psychological capital are more inclined to control their knowledge hiding behavior. In addition, some studies have found that highly confident and optimistic employees can feel motivated and can control their own fate (Alessandri et al., 2018). They are willing to devote the resources and effort and to meet any challenges (Stajkovic and Luthans, 1998). When employees with high psychological capital experience negative experiences at work, they are likely to adjust and bounce back from higher resilience. Finally, the higher the individual hopes, the higher their chances of finding multiple ways of success, and the lower the likelihood of having knowledge hidden. Therefore, employees with higher psychological capital will not avoid knowledge sharing and abandon their goals, but will choose to achieve their desired results in a positive way. Furthermore, we believe that the psychological capital ability of employees provides positive psychological support for their positive behavior of knowledge management and make the following assumptions:

As mentioned earlier, individual characteristics and abilities are crucial factors influencing knowledge hiding behavior. The adjustment of psychological capital is related to the psychological state of individuals in their environment (Ward and Kennedy, 2001; Fish, 2005). This concept is subjective and related to an individual's emotional state, cognitive perception, and personal characteristic variables (Zhang, 2013). Perceived overqualification is an essential feature of outstanding individuals, and psychological capital is influenced by a wider range of leading factors. Given the complexity of the knowledge hiding formation mechanism, it is reasonable to assume that psychological capital would be influenced by the perceived overqualification and play an intermediary role between perceived excess qualification and knowledge hiding.

Specifically, the individuals who perceived high overqualification can respond to and adapt to different working environments, thus changing their working patterns to be consistent with their unique qualifications. Zhang and Oczkowski (2016) put forward the differences between work adjustment, general living conditions adjustment, and interaction adjustment. We believe that these three capabilities are vital for individuals with perceptible qualifications in the organization, and to a certain extent, they reflect the resilience of employees. Karatepe and Talebzadeh (2016) believe that the perceived overqualification drives individuals to develop a positive work attitude to promote a trusting relationship in coordination with colleagues and the organizations, and then establish optimistic psychological ability, so that employees become proactive and flexible, eliminating the negative emotions caused by their high sense of seniority, which also helps to motivate employees to work more efficiently (Hakanen et al., 2018). With all the foregoing considerations, we believe that individuals perceived overqualification favors the formation of their psychological capital, which would have a further impact on knowledge hiding. Therefore, we recommend that:

Based on social cognitive theory, individual motivation and initiative are influenced by environmental information. The feedback of an organization to individuals will affects the judgments of self-efficacy and the production of positive behavior (Fugas et al., 2012; Zhang et al., 2014; Javed et al., 2021). Research on personal-organization fit (P-O fit) mainly manifests in the similarity between individuals and organizations. This similarity is the compatibility between personal and organizational characteristics of individuals, for example, whether the values and goals of the organization are in line with those of the individuals (Kristof-Brown et al., 2005; Akhtar et al., 2020). In other words, personal-organization fit indicates the consistency between the values of the individuals and the organization (O'Reilly et al., 1991).

Personal-organization fit is essential for perceiving overqualified individuals, as individuals may actively seek out aspects of the organization that are consistent with their aims, thus buffering the adverse effects of their objective mismatches with their jobs. This is reflected in the high degree of compatibility between the values and cultures of individuals and organizations (Follmer et al., 2018), organizations prefer their capability and values and provide a comfortable working environment for individuals to support their development (Maynard and Parfyonova, 2013). Perceived overqualified individuals appreciate the values and culture of the organization and accept the support of the organization. At this time, the individual reaches an agreement with the organization, forming favorable interactions (Wu and Chi, 2020). Eisenberger et al. (1997) argue that the individuals' perceptions of their qualifications and values are influenced by the level of organizational support. Taller personal-organization fit can make individuals more optimistic, and a large of research shows that personal-organization fit affects individual behavior. Edwards and Cable (2009) found three supportive mechanisms in the process of investigating why personal-organization fit generate positive effects. First, personal-organization fit can enhance the common understanding of right and wrong among individuals, thus strengthening the sense of trust between each other. Second, personal-organization fit can promote individuals' common understanding of the same event, which in turn improves their communication and interaction skills. Third, having common values increases the attractiveness of organizations and their individuals to each other. The higher the personal-organization fit, the perceived overqualified individuals are eager to leverage their perceived remaining skills by helping colleagues. Because of mutual trust, they are more pleased to share knowledge with others, and also increased attention to the internal affairs of the organization. They are more inclined to use the excess KSAs to serve their colleagues (Wu and Chi, 2020). Kristof (1996) pointed out that personal-organization fit refers to the overall environment in which individuals operate in the workplace and covers its various elements—organizational attributes: organizational culture, organizational climate, and norms; personal features: personality, values, goals, and attitudes (Wojtczuk-Turek and Turek, 2016). The “fit” between one's psychological climate and the current organizational atmosphere can represent a potentially important factor in employee job satisfaction (Joyce and Slocum, 1982). If the perceived personal-organization fit is high, then the employee's psychological and organizational atmosphere perception will remain consistent (Conner, 2014).

Further, the literature suggests that the employee psychological capital is positively associated with a perceived organizational support climate (Luthans et al., 2008). They propose that a supportive environment may help the psychological capital to flourish among employees. A supportive environment may make workers more resilient and hopeful, encouraging them to actively respond to setbacks and try new methods in their work. Wang and Xie (2021) also expounded on the effect of organizational atmosphere on employees' knowledge hiding in their research on organizational motivational climate. Organizational motivation atmosphere includes two dimensions: organizational control atmosphere and organizational performance atmosphere (Nerstad et al., 2013), among them, the organizational control atmosphere attaches importance to the sustainable development of individuals, encourages individuals to learn from themselves and colleagues to learn from each other, and establishes the common destiny among employees (Ntoumanis and Biddle, 1999). In the controlled atmosphere of an organization, the standard of employees' success is concerned with self-ability improvement, which encourages colleagues' mutual learning and grow together (Ntoumanis and Biddle, 1999). In this atmosphere, individuals hiding their knowledge is not conducive to group achievement, and individuals does not have to worry about sharing knowledge in the high personal-organization fit and organizational emotion (Černe et al., 2014). As a result, individuals are willing to make progress together by sharing their experiences or insights. In a similar vein, it is easy to establish trust during an interaction, mistrust is a key factor in knowledge concealment in a collective (Connelly et al., 2012), and trust can significantly reduce knowledge hiding behavior among members (Zhao and Xia, 2019), this is consistent with the mechanistic theory of personal-organization fit. According to social information processing theory, an important characteristic of humans is adaptability, and individuals adjust their behaviors and attitudes according to the information provided by their surrounding environment (Salancik and Pfeffer, 1978). Thus, we believe when there are higher levels of personal-organization fit; individuals with higher levels of overqualification are more inclined to share knowledge with others. We put forward the following hypothesis:

The overall conceptual model is exhibited in Figure 1.

Original data was collected for hypothesis testing by survey method based on a network questionnaire. The sample includes organizations in China where knowledge management processes are implemented. The sample population comprises the managers and individuals from state-owned enterprises, foreign-funded enterprises, private enterprises, and government units, all of which are known to be knowledge-intensive industries with knowledge resources and practices according to previous studies.

Before the questionnaire is distributed, as a pilot study, 18 academics from universities in China were invited to evaluate the validity and reliability of the proposed questionnaire. Initially, with the assistance of the Chinese Chamber of Commerce directories, the International Business Cooperation Office based in Kunming, the First People's Hospital of Yunnan Province and Union Shenzhen Hospital, 41 Chinese organizations where knowledge management practices are implemented participated in our survey. To reduce the influence of homologous deviation and clarify the logical relationship between variables, we collected data from the same population at two-time points, with an interval of 3 weeks for each survey in early and late April 2002 respectively. Due to the spread of the COVID-19 pandemic, all data surveys were collected via the standardized online platform Microsoft Forms (see questionnaire at http://www.microsoft.com/zh-cn/microsoft-365/online-surveys-polls-quizzes). The survey period was 6 weeks altogether, and a total of 307 responses were obtained, with 9 containing invalid values of more than 25% and 49 cases failed to satisfy the research criteria for the research, resulting in a final data set of 249 usable questionnaires.

As detailed below, existing scales from the literature were utilized, and measured on a 5-point Likert-type scale from 1 (strongly disagree) to 5 (strongly agree).

Common method variance (CMV) refers to the variance that is caused by measurement error than to the variable of the study (Bagozzi and Yi, 1991; Syed et al., 2021). It is an organized error variance common among the variables tapped with and emerges as a result of the same source or method used (Richardson et al., 2009). Common method variance generally exists in management studies, although self-assessment does not necessarily exist or create homogeneity, and method variance can deflate or inflate the true relationship between independent and dependent variables (Javed et al., 2020; Akhtar et al., 2022).

Since the data for each item all come from the same respondent, and the results are self-reported, it may lead to a problem of common method variance. Therefore in order to overcome CMV, we used different remedies (Aslam et al., 2021). First, to ensure the realness of the data, we kept the items clear in designing the questionnaire and reiterated that the questionnaire was completely anonymous for distribution. Secondly, our data are obtained from the same population by time and stage. Thirdly, in order to identify the distinctiveness of hypothesized model, we performed confirmatory factor analysis (CFA), where results reveal that (see Table 3) the model fitness of hypothesized model (χ² = 654.572, TLI = 0.952, CFI = 0.957, RMSEA = 0.060) is better than other models. It depicts that common method bias is not a concern in the present study. Finally, after the questionnaire was collected, we used Harman's single factor test (Podsakoff et al., 2003) to evaluate the negative influence of the common method bias. The findings indicated that the first factor without rotation explained 46.82% of the variance, which was <50% of the recommended value. Therefore, the common method bias is unlikely to cause considerable impact (Li C. S. et al., 2022; Li M. et al., 2022).

Table 4 illustrates the correlation coefficients and other statistics of constructs, which can preliminarily forecast the correlation coefficient. There are positive relationships between POQ and PsyCap (r = 0.64, p < 0.01); PsyCap and KH (r = −0.52, p < 0.01); POQ and KH (r = −0.49, p < 0.01).

We used Amos 26 to test the relationship between variables, and the results show where the fit index of each variable was acceptable (see Table 5). Additionally, structural model fit index was also acceptable: (χ² = 298.497, df = 146; χ²/df = 2.044; IFI = 0.970, TLI =0.964, CFI =0.970, RMSEA = 0.065, RMR = 0.048).

As predicted, POQ has a significant positive association with PsyCap (β = 0.688, p < 0.001), which indicated the direct effect of POQ on PsyCap was confirmed. Therefore, H2 is supported. In addition, PsyCap was related negatively to KH (β = −0.401, p < 0.001), and POQ also had a negative association with KH (β = −0.325, p < 0.001), which indicated preliminarily the existence of indirect effect (see Table 5). Therefore, H1 and H3 are also supported.

We used Hayes's (2017) Macro Process model for mediation analysis. Hayes' PROCESS (5,000 bootstrapping was specified) was used to test hypothesis 4 (see Table 6 for the results). The mediation hypothesis in this paper was confirmed by the prominent indirect effect (indirect effect = −0.224, 95% CI = [−0.321, −0.128]). Thus, psychological capital mediated the correlation between POQ and KH, thus, Hypothesis 4 was also accepted.

Following Hayes and Andrew (2009), we apply PROCESS 3.4 to examine the moderating role of person-organization fit on the relation between POQ and KH by 5,000 bootstrap samples. We also ran Process Model 1, in which the P-O fit moderated the association between the POQ and KH. The consequences in Table 7 showed interaction item moderating negatively the relationship between POQ and KH (β= −0.552, LLCI = −0.216, ULCI = −0.049). To analyze further the moderating effects, in Figure 2, we used a simple slope test to observe the strength of the negative correlation between POQ and individual KH at high and low levels of P-O fit, respectively. As shown in the figure, the negative correlation between POQ and KH is slow when the P-O fit is low. When P-O fit is higher, it enhances the negative correlation between POQ and KH, indicating that when individuals' P-O fit is high, POQ will reduce KH behavior. Therefore, H5 is supported.

First, this research increases the literature on hidden knowledge from the subjective perspective of employees and expands the scope of knowledge hiding in the knowledge management system. The researchers acknowledge that knowledge hiding is an important factor requiring high attention and that some attention has been given to its impact based on employee perceived overqualification. These studies provide important insights into the perceived excess qualification and knowledge hiding, namely that the perceived overqualification is one of the main reasons behind this factor. The existing literature lacks new empirical evidence for the existence of a negative intrinsic link between the perceived overqualification and knowledge hiding. Our study also helps to extend the knowledge about the perceived overqualification through its findings. Based on our results, employees identified their KSAs as an essential asset they bring to the workplace and the organization, and their surplus qualifications are valuable additions to the organization. Because of their initiative in the team or organization, they may bring greater benefits to the team or organization. This study shows new empirical evidence for the existence of a causal relationship between the perceived overqualification and knowledge hiding. Our work responds to the academic call for more research on the potentially positive aspects of the perceived overqualification and the reasons for knowledge hiding and the consequences of these practices (Hu and Liden, 2015; Luksyte and Spitzmueller, 2016; Lin et al., 2017; Deng et al., 2018; Van Dijk et al., 2020).

Second, this study has made an important contribution to knowledge hiding by testing the mediation of psychological capital and the moderation of person-organization fit. Previous studies have rarely considered their predecessor, and in the past have examined knowledge concealment with working conditions, executive behavior, or situational factors. The subjective experience of employees' perceived overqualification has done less research on knowledge hiding, and overqualification is a common concern of organizations today. It is crucial to focus on this factor, as employee perceived overqualification is closely related to work status. The research on knowledge hiding is especially lacking in terms of potential positive aspects of the perceived overqualification. Our study found that when employees perceived overqualification, due to strong role self-efficacy and positive psychological cognition, employees will respond to teams or organizations by seeking more active or broader ways, that is, psychological capital will effectively affect employees' knowledge hiding behavior to a certain extent. From the theoretical perspective of person-organization fit, knowledge hiding is reduced when employee values align with organizational values. Due to psychological capital, this study enriched the research on the influencing factors of employee subjective perspective “POQ” on knowledge hiding, confirming that the perceived overqualification is negatively linked with knowledge hiding.

Third, we also examined a moderated factor, “P-O fit” when addressing the negative effect of the perceived overqualification. Person-organization fit can relieve the positive impact of the perceived overqualification on knowledge hiding. By studying the moderated function of person-organization fit, we provide a novel and important condition for the effect of the perceived overqualification on employee psychology and performance (Bari et al., 2020). Our findings show that employees working in a team or organization with a better atmosphere and meeting their values can decrease the passive impact of the perceived overqualification, and also have a positive impact on their psychological capacity building.

Our research sheds new light on the consequences of overqualification for business practitioners. First, our findings suggest that overqualification is not the relative deprivation of overqualification and waste of talent. Employees can use their excess KSAs to temper their psyches and do more. They achieve self-efficacy by accomplishing a wider range of tasks, and they can actively make pro-social changes (Grant and Ashford, 2008; Parker and Collins, 2010). Overqualification will not only stimulate their sense of value in the team, organization, and society, and drive them to better job performance and respect for others. We stand for that the outcome of the perceived overqualification may vary; it depends on one's mind and attitude. That is, whether an individual wants to be an outstanding person of the general population or an ordinary person among the best group. When an employee perceives overqualification, he/she may conduct more job-seeking behaviors (Maynard and Parfyonova, 2013). In this study, we think that employees who perceive overqualification will pay more attention to their residual ability rather than insufficient working conditions, and are more likely to take the opportunity to take the initiative to complete more tasks, especially in an atmosphere full of organizational support, employees with greater psychological capital ability and higher levels of person-organization fit have greater probabilities to perform better.

First of all, from the perspective of the potential positive role of the perceived overqualification, this study discusses the reasons for the inconsistency between employees' perceived overqualification and employees' active work behavior in the existing research, which has a certain practical guiding value. It is suggested that managers should pay attention to employee selection and post allocation, fully understand employees' career development goals, analyze their post adaptability, and evaluate whether the enterprise can meet employees' needs and expectations.

Second, this study proposes the mediation role of psychological capital in the path between employees' sense of excess qualification and employees' knowledge hiding behavior. Based on social embeddedness theory, it verifies the influence process mechanism of “perceived overqualification—psychological capital—employees' knowledge hiding behavior”, which enriches the research results of the relationship between psychological capital and knowledge hiding behavior. Given that psychological capital plays an important role between employees' perceived excess qualification and knowledge hiding, it is suggested that enterprises with the problem of employees' excess qualification should take how to build employees' psychological capital and positive psychological cognition as the management focus. For example, arrange work carriers for employees with excess qualifications that can demonstrate their qualifications, release their qualification energy, and meet the expected benefits of qualifications to stimulate their knowledge sharing behavior. According to employees' unique abilities and psychology, through professional training and development plans, guide employees to continue to move in the right direction, and make full use of their qualifications to achieve the best interests of the team or organization.

Third, our results show that person-organization fit positively regulates the relationship between excess qualification and knowledge hiding at the individual level. Accordingly, enterprises should attach importance to employees' recognition of enterprise values and corporate culture, as well as the construction and maintenance of enterprise organizational atmosphere, pay full attention to, support and trust employees' contributions, create a psychological safety atmosphere for employees, provide them with opportunities to display their talents, and encourage and support employees' extra job behaviors beneficial to the organization to enrich their current work. So as to strengthen the identification of employees with excess qualifications with the organization, and then make employees show more positive behaviors.

This paper has several limitations that should be resolved in future studies. First, since all the main variables in the study were fully self-reported in the form of a questionnaire since knowledge concealment is a more sensitive and negative topic, respondents may not give completely true responses due to social desirability bias. Therefore, we expect future non-self-reported, more credible ways to investigate perceived excess of qualification and knowledge concealment. Second, the types of the perceived overqualification vary with each individual. According to Maynard (2011), common studies all assume that employees want to use their KSAs to obtain a higher salary. However, some people may receive far less for their interest or sense of mission than they can be paid for their potential abilities. Maltarich et al. (2011) have proposed the concept of “intentional mismatch”, which proves that many people make different choices about their work because of their different needs. The perceived overqualification does become a deprivation in most cases, but in certain situations the potential positive effects of the perceived overqualification can produce excellent results. Third, we found that employees' psychological capital plays an intermediary role in the covering relationships and this can be further examined and validated on different samples across various cultural backgrounds in future research. Meanwhile, we investigated the moderating effect of person-organization fit on the relationship between the two key variables, and confirmed its active effect. In addition to person-organization fit, future researches can explore the other situations where the beneficial effects of the perceived overqualification are ignored or highlighted. In addition to the situational variables and employee personal psychological factors variables in this study, future studies can examine more personal characteristic variables or bias variables as moderators or mediators from the perspective of managers to gain insight into how managers capture potential positive outcomes of the perceived overqualification.