HRM Practices and Work Engagement Relationship: Differences Concerning Individual Adaptability

: The importance of human resource management (HRM) practices to improve organizational attitudes and behaviors is not yet widely acknowledged. However, is not clear whether the effect of HRM practices on outcomes vary depending on the level of speciﬁc personal resources. The present paper aims to examine the relationship between HRM practices and work engagement by focusing on the moderating role of adaptability. We used cross-sectional data with surveys from 1219 Italian employees in public, private, and non-proﬁt organizations. The results of structural equation models (SEM) showed that HRM practices were positively related to work engagement overall for employees with low adaptability. Therefore, adaptability moderated the relationship between HRM practices and work engagement. In terms of originality, this study is based on the paucity of empirical studies linking developmental HR practices to employees’ work engagement. Hence, the present study addressed this gap by examining the relationship between the perception of HRM practices and work engagement, as well as how adaptability moderated this relationship. These ﬁndings are discussed in terms of their theoretical and practical implications for HRM. between HRM practices and adaptability on work engagement.


Introduction
In a competitive working scenario, organizations are forced to increase productivity and performance. Organizations are constantly adapting to growing international competition, a diversified workforce, and an increasingly complex work environment exacerbated by the COVID-19 pandemic. It has long been recognized both in theory and in practice that employees' engagement can improve well-being and performance [1]. Therefore, the current world of work has made employee work engagement a crucial key issue for organizations. The findings of empirical studies have been focused on the numerous antecedents of work engagement (WE) (for a recent meta-analysis review, see [2]). However, human resource management (HRM) practices as an antecedent of work engagement have been rarely investigated [3,4]. HRM practices refers to those practices that have the potential to improve and sustain organizational performance [3][4][5]. These practices may be identified as a function of the performance outcome wanted by the organization. Over the years, researchers have identified some frequently cited HRM practices, including those referring to recruitment, selection procedures, training and development, performance evaluation practices, and job security [6]. Generally speaking, scholars agree that appropriately designed HRM practices can enhance organizational outcomes because practices influence employees' attitudes and behaviors [6]. With this consideration in mind, this study focused on those HRM practices suggested by Gould-Williams and Davies [7] that were found to be related to enhance workers' performance through empowerment, development, and trust to achieve organizational goals. In this study, specific types of HRM practices were considered, concerning the following: communication programs in order to provide to employees information about their work; training and development programs in order to offer to employees opportunities to develop task-related skills; selective hiring in order to identify suitable candidates; and provision of adequate opportunity for employees' careers. Only recently, there has been increased interest in the impact of HRM practices on employee work engagement [8]. Some researchers have reported that HRM practices represent one means through which employers can indicate their intentions to invest in and support their employees and that such signals are seen as a necessary precondition for engagement [9,10]. Other researchers have highlighted the need for organizations to understand how employees' levels of work engagement could be improved through HRM practices [11][12][13]. The scant literature opens up new research scenarios including the possible interviewing role of additional variables in the relationship between HRM practices and work engagement. As a matter of fact, the previous literature has not yet investigated whether the effect of HRM practices on engagement is conditioned by employees' personal resources. In order to fill this gap, the present study investigated the association between HRM practices and work engagement by taking into account adaptability, as an individual-difference moderator variable on this relationship. Adaptability concerns the individual ability to successfully adapt to changes in the workplace [14]. Adaptability is a personal characteristic that resides within the individual. A personal characteristic means that adaptability is a not a characteristic of the situation and that cannot be shaped by the context or environment. Individual adaptability impacts on the way in which people perceive and cope with different situations [14]. Previous research on adaptability has focused on this variable considering its relation to task performance, cognitive process, coping, and organizational change [14]. In this study, the focus is on adaptability as an employee's disposition to change his/her behavior according to the situation and assume that employees have different levels of adaptability when at work. Therefore, this could be considered as personal resources. By integrating employee adaptability into the relationship between HRM practices and their work engagement, the present study may contribute to previous literature about HRM in several ways. First, the findings related to HRM practices support the assumption that these practices are important not only for the practices themselves, but also from the employees' perceptions on these. Second, this study investigates an understudied individual-difference resource and its role in the HRM practices and work engagement relationship. This lends greater precision to the understanding of the strategic role of employee engagement and, as a consequence, the organization. Third, this study considered for the first time adaptability as a moderator variable in the relationship between HRM practices and a positive attitude in the working context, i.e., work engagement in a sample of Italian subjects employed in private, public, and non-profit organizations. In this study, we first propose a specific and well-known theoretical framework, i.e., social exchange theory (SET) [15], regarding the relationship between HRM practices and work engagement. Furthermore, it has been argued that this relationship may vary across employees with different levels of adaptability. Finally, we discuss the theoretical and practical implications of our findings.

HRM Practices as an Antecedent of Work Engagement in Social Exchange Theory?
As already mentioned, HRM practices can be considered as an umbrella term composed of different types of organizational practices. These practices may also concur to improve work engagement levels. According to Schaufeli and colleagues [16], work engagement can be defined as a positive psychological state, characterized by energy, dedication, and absorption. Empirical studies have shown that engaged workers are energic and positive, dedicated to their work, and completely immersed in their job tasks [17]. Work engagement may lead to many benefits for everyone. At an individual level, because work engagement allows to employees to use their talents, at an organizational level because, consequently, employees' effectiveness and performance tend to improve [18]. Due to its well-recognized and strategic role, over the past two decades, research in the work engagement field has rapidly increased [19]. Although a large number of studies have considered the antecedents of WE, only recently has research started to investigate distal antecedents such as HRM practices [8]. This concept could be considered a critical antecedent, affecting positively work engagement [20].
A review of the scant literature suggests that HRM practices can have a noteworthy weight on employee outcomes such as work engagement [11,21]. HRM practices can be viewed by the employees as a set of job resources that enhance the proper working conditions. Following this line of reasoning, employees will be more likely to feel involved in working activities due to a personal positive state of mind related to the work, i.e., work engagement, rather than because of feeling coerced into them.
The theoretical support for this study is SET [15], according to which relationships between employees and employers are based on norms of reciprocity generated through a series of interactions between parties who are in a state of reciprocal interdependence. These relationships evolve over time into trusting, loyal, and mutual commitments as long as the parties abide by certain "rules" of exchange [22]. Rules of exchange usually involve reciprocity: the actions of one party lead to reactions by the other party. More specifically, where employees perceive that organizations treat them well, they tend to respond by exerting effort, and engaging more in their own work activities [23]. Practically speaking, the implementation of HRM practices by the organization is viewed by employees as an organization's commitment towards them, which is then reciprocated back to the organization by employees through positive behaviors [24,25] and attitudes such as work engagement [20]. Thus, employees are more likely to exchange their engagement for resources and benefits provided by their organization [26].
Accordingly, we propose the following hypothesis: Hypothesis 1 (H1). HRM practices will be positively related to work engagement.

The Moderating Role of Adaptability
Adaptability refers to cognitive, behavioral, and emotional adjustments that employees could make in the workplace [27]. Individual adaptability is not a characteristic of the working situation, nor does it occur only in response to a change in the organizational environment or job task. Therefore, adaptability does not depend on how employees appraise the organizational environment; rather, it is a personal characteristic.
In this turbulent and uncertain world of work, especially in organizational settings, employees with adaptability are particularly sensitive because they are ready to react accordingly with an adaptive change. Moreover, employees' adaptability can positively affect their attitudes in the workplace, including work engagement. Adaptability could be seen as a driver to enhance work engagement and, consequently, push employees to perform at consistently high levels, driving innovation and moving their organization forward. Regarding the relationship between different types of HRM practices and work engagement, the findings of some recent studies have showed inconsistent associations [4]. One of the reasons for these inconsistent results may be due to the fact that previous studies have not considered the role of additional variables, including personal resources. In other words, it seems necessary to incorporate moderator variable(s) into these relationships. There are currently no specific studies analyzing the moderator role of personal resources in the relationship between HRM practices and work engagement. Therefore, in order to fill this gap in the literature, we proposed to investigate adaptability as a moderator. As a matter of fact, the effects of HRM practices on engagement may vary according to different levels of adaptability. In line with SET, employees give back to organizations, also in motivational and behavioral terms, what they perceive to receive from the organization. Therefore, employees with fewer personal resources, such as adaptability, may perceive receiving more from the organization, in terms of HRM practices, and consequently give back more. More explicitly, we propose that the positive effect of HRM practices on engagement is stronger for employees with low levels of adaptability than employees with high or medium levels. Therefore, we propose the following hypotheses: Hypothesis 2 (H2). Adaptability will moderate the effect of HRM practices on work engagement. Specifically, when employees perceive high levels of HRM practices, employees with low levels of adaptability will have higher levels of engagement than employees with high levels of adaptability.

Materials and Methods
The present study is a part of a large-scale research project of the Work in Progress (WiP) research group of the Italian Psychological Association. According to the research protocol, researchers selected employees via a snowball procedure, beginning with employees known to the researchers. The questionnaires were presented via computer-assisted web interviewing (CAWI), through an online platform. Following ethical guidelines, any information about research, including free and voluntary participation, was described in the first page of the online questionnaire. By clicking on the appropriate button, participants agreed to complete the questionnaire. After completing the questionnaire, each participant was asked to send the link to other employees.

Sample
The participants included 1219 Italian employees, 45.7% women and 54.3% men, working in the public (33%), private (64.2%), or non-profit (2.8%) sector (Table 1). Furthermore, 62.1% were permanently employed and 24.4% were temporary employees. On average, the participants were 36.69 years old (SD = 12.98), ranging from 18 to 67 years old. Regarding education, 43.5% had a university degree, 50.6% had a high school diploma, and the remaining 5.9% had only completed compulsory education.

Measures
HRM practices were measured using an eight-item scale assessing an employee's perception about nine high-performance attributes: selection, training, development, teamwork, job security, pay, communication, involvement, and performance appraisal. Respondents were asked to indicate the extent to which they strongly agreed or disagreed with eight statements relating to HRM practices (sample item: "Management involve people when they make decisions that affect them"), using a Likert scale ranging from 1 (strongly disagree) to 7 (completely agree). The scale, developed by Gould-Williams and Davis [7], showed high validity and reliability. In the present study, Cronbach's alpha was 0.91.
Adaptability was assessed by six items of the Individual Adaptability (I-Adapt) Questionnaire [14]. Respondents were asked to indicate the extent to which they strongly agreed or disagreed with six statements relating to different issues of adaptability (sample item: "I believe it is important to be flexible in dealing with others"), using a Likert scale ranging from 1 (strongly disagree) to 5 (completely agree). Cronbach's alpha was 0.70.
Work engagement was assessed by the Italian version [28] of the short version of Utrecht Work Engagement Scale [29]. It was composed of nine items (sample item "I am enthusiastic about my job"), with a Likert scale ranging from 1 (never) to 7 (always). In the present study, Cronbach's alpha was 0.95.

Statistical Analyses
Preliminarily, we examined the measurement model for the full set of data via confirmatory factor analysis (CFA). The hypothesized three-factor model was compared with an alternative model in which all observed variables loaded onto a single latent variable (i.e., Harman's single-factor test). CFAs were tested with Mplus v.8 [30], evaluating the following fit indices: root mean square error of approximation (RMSEA; if ≤0.08, the model shows a good fit), comparative fit index (CFI; if ≥0.90, the model shows an acceptable fit), and standardized root mean squared residual (SRMR; if ≤0.08, the model shows an acceptable fit).
After establishing the measurement model, the moderation hypotheses were tested following the two-step approach [31]. In the first step, Model 1 including the effects of HRM practices and adaptability was evaluated; in the second step, the latent interaction term was included (Model 2) in the model. As suggested by Barbaranelli and colleagues [32], Model 2 should be compared with Model 1 by information criteria (see Kline [33]), such as the Akaike information criterion (AIC), the Bayesian information criterion (BIC) and the sample size-adjusted BIC (SABIC), preferring the model showing the lowest information criteria values.

Results
In Table 2 are reported the descriptive statistics and zero-order correlations for the study variables computed as scale means. HRM practices were positively correlated to adaptability and work engagement, and adaptability was positively correlated to work engagement.
Afterwards, we tested the moderation hypotheses following the two-step approach [31]. In the first step, Model 1, without the latent interaction, showed an adequate fit to the data: As hypothesized, HRM practices were positively and significantly related to work engagement (β = 0.462; p < 0.001), supporting H1. Furthermore, adaptability was also positively and significantly related to work engagement (β = 0.371; p < 0.001).
In the second step, we added the latent interaction. Model 2 showed the following information criteria values: AIC = 76,950.54; BIC = 77,338.52; SABIC = 77,097.11. Model 2 should be preferable to Model 1 because its information criteria values were lower, suggesting that the latent interaction did not lead to a worse overall model fit. Furthermore, Model 2, with the inclusion of the latent interaction, significantly increased the overall proportion of explained variance in work engagement of about 3%, compared to Model 1. Figure 1 depicts standardized estimates from Model 2, with coefficients of the structural path closely to those of Model 1. As a matter of fact, HRM practice (β = 0.474; p < 0.001) and adaptability (β = 0.356; p < 0.001) were positively and significantly related to work engagement. The latent interaction of HRM practice X adaptability on work engagement was significant and negative (β = −0.079; p < 0.001). As hypothesized, HRM practices were positively and significantly related to work engagement (β = 0.462; p < 0.001), supporting H1. Furthermore, adaptability was also positively and significantly related to work engagement (β = 0.371; p < 0.001).
In the second step, we added the latent interaction. Model 2 showed the following information criteria values: AIC = 76,950.54; BIC = 77,338.52; SABIC = 77,097.11. Model 2 should be preferable to Model 1 because its information criteria values were lower, suggesting that the latent interaction did not lead to a worse overall model fit. Furthermore, Model 2, with the inclusion of the latent interaction, significantly increased the overall proportion of explained variance in work engagement of about 3%, compared to Model 1. Figure 1 depicts standardized estimates from Model 2, with coefficients of the structural path closely to those of Model 1. As a matter of fact, HRM practice (β = 0.474; p < 0.001) and adaptability (β = 0.356; p < 0.001) were positively and significantly related to work engagement. The latent interaction of HRM practice X adaptability on work engagement was significant and negative (β = −0.079; p < 0.001). The simple slope of the latent interaction is reported in Figure 2. It shows that when HRM practices are low, the levels of work engagement are also low, for low (−1 DS), medium (mean), and high (+1 DS) levels of adaptability. However, when HRM practices increase, levels of work engagement also increase, in particular for employees with low adaptability. The simple slope of the latent interaction is reported in Figure 2. It shows that when HRM practices are low, the levels of work engagement are also low, for low (−1 DS), medium (mean), and high (+1 DS) levels of adaptability. However, when HRM practices increase, levels of work engagement also increase, in particular for employees with low adaptability.

Discussion
Over the last decades, research in the field of HRM investigated how and what HR practices stimulate employees [34], including attitudes such as work engagement [4,7]. Moreover, research on organizational antecedents of work engagement has moved the focus on the importance of employees' perceptions and interpretations of HRM practices. The present study investigates the impact of employees' perceptions of HRM practices on their levels of work engagement in light of SET as the theoretical framework. In addition, a moderator variable was included, i.e., adaptability, into this relationship in order to propose an empirical contribution in the connections between HRM practices and employees' work engagement. Adaptability as a moderator variable was chosen for the need to adapt in today's dynamic working environment, where employees are called to cope with new challenges daily.
To the best of our knowledge, the present research is the first that shows that the effect of HRM practices on the positive psychological work mindset varies for different levels of individual adaptability.
The results reveal that HRM practices are positively associated with work engagement, and this is positively associated with adaptability; specifically, when HRM practices increase, levels of work engagement also increase, in particular for employees with low adaptability. As mentioned earlier, our predictions were based on SET. The employee's feeling that the organization is interested in him/her through HRM practices has a positive impact on the social exchange between employees and the organization. This effect could be crucial to stimulate organizational outcome as work engagement specifically for employees with low levels of adaptability. In this way, adaptability levels can explain better the differences between employees on work engagement overall for those who do not have a sufficient ability to adapt within the organization. Therefore, our findings extend previous research on the association between organizational HRM practices and work engagement [11][12][13]. Furthermore, our results provide a greater understanding of what kind of employee personal resources influences the relations between their perceptions of HRM practices and their levels of work engagement.

Discussion
Over the last decades, research in the field of HRM investigated how and what HR practices stimulate employees [34], including attitudes such as work engagement [4,7]. Moreover, research on organizational antecedents of work engagement has moved the focus on the importance of employees' perceptions and interpretations of HRM practices. The present study investigates the impact of employees' perceptions of HRM practices on their levels of work engagement in light of SET as the theoretical framework. In addition, a moderator variable was included, i.e., adaptability, into this relationship in order to propose an empirical contribution in the connections between HRM practices and employees' work engagement. Adaptability as a moderator variable was chosen for the need to adapt in today's dynamic working environment, where employees are called to cope with new challenges daily.
To the best of our knowledge, the present research is the first that shows that the effect of HRM practices on the positive psychological work mindset varies for different levels of individual adaptability.
The results reveal that HRM practices are positively associated with work engagement, and this is positively associated with adaptability; specifically, when HRM practices increase, levels of work engagement also increase, in particular for employees with low adaptability. As mentioned earlier, our predictions were based on SET. The employee's feeling that the organization is interested in him/her through HRM practices has a positive impact on the social exchange between employees and the organization. This effect could be crucial to stimulate organizational outcome as work engagement specifically for employees with low levels of adaptability. In this way, adaptability levels can explain better the differences between employees on work engagement overall for those who do not have a sufficient ability to adapt within the organization. Therefore, our findings extend previous research on the association between organizational HRM practices and work engagement [11][12][13]. Furthermore, our results provide a greater understanding of what kind of employee personal resources influences the relations between their perceptions of HRM practices and their levels of work engagement.

Theoretical Implications
It has been acknowledged that HRM practices may play a crucial role in influencing employee work-related attitudes [35]. The relationships between HRM practices and work engagement have been somewhat explored in previous studies [4,7,36]. However, in most studies, HRM practices were linked to work engagement. As a result, researchers share a common approach that the perception of HRM practices for employees plays an important role as an antecedent in developing employee engagement. However, this relationship may be further explained by the perception of adaptability of employees. Some explanations are given below.
By linking the HRM practices to work engagement, this study created an opportunity to provide new, different explanations for this relationship. Among the most important, following Gould-Williams and Davies [7], HRM practices in the present research were evaluated by some representative types of practices that would be able to better represent the complexity of this organizational variable.
The findings highlight the positive association between perceived HRM practices and benefits to work engagement. This finding has two main implications: first, it confirms the conclusions of previous studies [4,23] in that the perception of HRM practices is relevant to work engagement [8,10]. Second, our results support and refine previous studies by highlighting that specific types of HRM practices have a positive connection with a workrelated and positive attitude such as work engagement. Furthermore, this study explains how employee adaptability may contribute to employee work engagement. Specifically, our findings suggest that the levels of adaptability of employees have distinct effects on work engagement. In the last decade, the working scenario has rapidly and deeply changed, particularly for organizations worldwide; the employees within these organizations have been forced to cope with different pressures that require adaptability [37,38]. Based on these assumptions, this study included adaptability as a moderator variable in the relationship between HRM practices and work engagement. The findings show that, at high levels of HRM practices, employees with low adaptability were more involved than employees with high and medium adaptability. This noteworthy result could be explained in light of the theoretical framework of SET, where employees that report high levels of HRM practices (tangible organizational resources) have high levels of work engagement (in the form of repaying the organization), in particular for employees with low adaptability. This suggests that it is possible that HRM practices are able to compensate for the eventual lack of personal resources, i.e., a low level of adaptability. In interpreting the effect of adaptability, it should be noted that adaptability in this study was measured in terms of a personal characteristic and therefore was treated as an individual-difference variable. Due to the competitive and challenging work context, our results may inspire future studies to explore different personal characteristics as moderators that could work in organizational settings.

Practical Implications
The results provide some implications for HRM. First, to design and implement HRM practices, HR professionals need to focus not only on different types of these practices such as communication, training and development programs, hiring procedures, and opportunity for employees' careers, but also on employees' individual resources. Therefore, HR practitioners could enhance employee outcomes by offering targeted HRM practices. In this regard, an individual growth path through HRM practices related to learning to incorporate new tasks had a positive relationship with work engagement [39]. According to our findings, HRM practices can have effects on employee-level outcome variables [9] in organizations with more engaged employees.
Second, the results recommend that employees' adaptability plays a role in the work engagement process. Therefore, HR departments can use this insight to increase personal adaptability as a personal resource. For example, at the micro level, for employees, those with low levels of adaptability can be involved in training programs to improve this personal characteristic and to stimulate their work engagement. At the macro level, for organizations, adaptability can be enhanced through a positive organizational culture. Therefore, organizations with a positive culture also foster work engagement in their employees. Focusing on personal resources such as adaptability, HR departments should take care of their own employees; organizations should promote organization positivity and get their employees to become more engaged, which could stimulate employees to be better able to adapt to their changing work environment.

Limitations and Future Research
Some limitations of the present study should be acknowledged. First, a correlational approach was used to investigate the relationship between HRM practices and work engagement. Therefore, the investigated relationship may be reciprocal. If the proposed path model can follow an inverse direction, HRM practices can influence work engagement, but the perception of work engagement also directs employees' perceptions of HRM practices. Therefore, further studies should investigate this reciprocal relationship by a longitudinal approach. Furthermore, future research, as stated above, should consider additional personal characteristics, such as healthy employees' resources [34], and different organizational contexts should be considered [40].
Another shortcoming concerns the outcome variable. The results would have been more convincing if additional work-related attitudes had been included. Fourth, data were collected from the same source. This sample design could lead to common method variance. To isolate this bias, a single-factor CFA was conducted, and the structure of the measures was identified before testing the hypotheses [41]. Finally, the samples used in this study were just from Italy; there might be a specific bias in the perception of adaptability due to the particular Italian labor market. In this regard, whether the findings can be generalized across national boundaries remains a question. On this point, future research with a cross-cultural approach is needed.

Conclusions
The relationship of the perceptions of HRM practices and their work engagement were investigated in this study, using adaptability as a moderator. The results show that HRM practices are positively related to work engagement, and adaptability moderates this connection. These findings make three main contributions. First, they prove evidence and support previous studies that HRM practices are related to a specific work-related attitude, such as work engagement. Second, they shed new light on the key role of adaptability as a moderator in that relationship. Third, they provide noteworthy support to consider the personal resources of employees as a strategic component in an organizational context.

Data Availability Statement:
The data presented in this study are available on request from the corresponding author. The data are not publicly available due to privacy reasons.