The Relationship between Inclusion Climate and Voice Behaviors beyond Social Exchange Obligation: The Role of Psychological Needs Satisfaction

: Several studies have identiﬁed a work environment that promotes inclusiveness as a signiﬁcant predictor of afﬁliative organizational citizenship behavior or OCB (such as helping), whereas not much research has focused on inclusion and challenging OCB (i.e., voice). Moreover, no previous studies have explored the above-mentioned relationship in the light of self-determination theory (SDT), given that social exchange theory has traditionally been used as the main explanatory mechanism. Therefore, the aim of the present research was to test the mediating role of basic psychological needs satisfaction in the relationship between inclusion climate, promotive voice and prohibitive voice. Data were collected through self-report questionnaires administered to 246 employees of an international company operating in the service industry. Structural equation modelling was used to analyze the data utilizing R software. Results showed that satisfaction of the needs for autonomy, competence and relatedness partially mediated the relationship between inclusion climate and promotive and prohibitive voice, therefore supporting the idea that social exchange might not be the only determinant for employees to engage in voice behavior. Most importantly, those ﬁndings underline how a truly inclusive workplace needs to fulﬁl its employees’ basic needs of behaving volitionally, feeling effective and connecting meaningfully; this would motivate the workers to voice their suggestions and concerns.


Introduction
Exclusion and marginalization of significant social groups is considered one of the main dilemmas which requires long-term efforts and measures for the development of sustainable organizations [1]. First, organizations can be defined as sustainable when much of their innovation is provided through inclusive human resources management, so that their innovative performance is a product of the investment in the social and environmental areas [1]. Second, and more importantly, the imperative of a sustainable organization is tackling economic and social inequalities; this can be realized through actions supporting, amongst other things, the achievement of decent and healthy work conditions for everyone, as stated in the 2030 Agenda for Sustainable Development [2].
However, despite the political and societal efforts to promote work settings that support diversity, workplace exclusion still prevents employees of different backgrounds from fully contributing to and benefiting from their organizations [3,4].
The prevailing literature suggests that when organizations create fair and inclusive environments, where employees are treated as insiders whilst keeping their uniqueness [5], those employees are likely to respond by demonstrating desirable behaviors that are valued by the organization [6,7], including organizational citizenship behaviors [8].
Extra-role behavior, namely organization citizenship behavior (OCB) is defined as "individual behavior that is discretionary, not directly or explicitly recognized by the formal reward system and, in the aggregate, promotes the efficient and effective functioning of the organization" [9] (p. 4).
In early research, OCB was described and operationalized as equivalent to the constructs of prosocial behavior, interpersonal helping, and altruism (e.g., [9,10]). The last 25 years have seen an increase in research aimed at questioning and challenging the dominant assumption that OCBs are solely focused on pro-sociality [11]; more specifically, those studies have contributed to show that OCB might originate from more self-serving or mundane motives and that their impact on organizational performance is variable [12]. Based on those developments, existing literature on OCB has acknowledged the existence of two forms of citizenship behaviors [13]. The first one is affiliative OCB, which includes behaviors aimed at maintaining the status quo through promotion and support of the existing working processes and relationships [14]. Therefore, affiliative behaviors are prosocial, based on cooperation and noncontrovery [15], and they comprise acts such as helping others and showing courtesy. The second form is challenging OCB, which refers to behaviors directed toward changing the status quo with the intention to constructively challenge and improve work procedures or relationships [13]. Examples of challenging OCB include promoting and prohibitive voice [16]. Both affiliative and challenging types of OCB are actions aimed at supporting the social and psychological environment for the benefit of the organization [17]; nevertheless, past literature has disproportionately focused on affiliative OCBs (primarily prosocial and helping behaviors), especially in the service industry (e.g., [18][19][20]).
Additionally, most of the research on OCB has relied massively on social exchange theory [21] as the main paradigm to explain how OCBs operate [22], with particular reference to perceptions of justice and inclusion [23]. More specifically, multiple studies identified some significant antecedents of OCBs, such as perceived organizational support (e.g., [24][25][26]), perceived justice (e.g., [27]), a climate for diversity (e.g., [28][29][30]), and inclusion (e.g., [31,32]). The relationship between workplace climate and OCB has often been explained through the existence of a direct link between what the organization offers to employees and what they give back in terms of OCB [8]. More specifically, a work environment that promotes inclusiveness is one where employees are treated as insiders while keeping their uniqueness [4,5]. In such a work climate, employees will feel they are appreciated for the unique value each of them represents in the eyes of the organization and the unique input each of them contributes; as a consequence, they will tend to reciprocate by behaving the way they perceive they are treated [8]. Namely, if they perceive their organization treats them with trust, fairness, and concern or interest, then they will feel an obligation to avoid destructive actions, this resulting in increased job performance and higher levels of OCB [33].
If social exchange theory has demonstrated the link between diversity, inclusion and affiliative OCBs in a satisfactory way, there is a paucity of research exploring the effect of diversity and inclusion on challenging OCBs, especially on voice behaviors. Those behaviors represent change-oriented actions that aim at suggesting improvements and, for this reason, they can disrupt or alter an organization's status quo [34]. Moreover, those types of actions can be particularly relevant when speaking up is related to a justice violation, because the employee might consider the consequences not only for other people but also for him/herself [35]. This evaluation of possible outcomes might be only one of the explanations for the fact that not all employees engage in voice behavior, therefore stressing the need for further research on the mechanisms that drive those behaviors beyond the principles of reciprocity and social exchange [36,37]. In fact, considering the assertive and nonconformist nature of voice, research has also started to examine motivational factors [38] which can explain the internal drive of an individual to speak out and constructively criticize organizational processes and practices.
Given all those premises, the present research contributes and adds to the current literature by (a) clarifying the role of inclusion climate in employees' engagement in promotive and prohibitive voice behaviors; (b) investigating the above-mentioned relationships in light of alternative driving mechanisms, based on self-determination theory [39]. Specifically, self-determination theory proposes that people have basic psychological needs for autonomy, competence, and relatedness that need to be fulfilled for the individual's optimal functioning and growth; the satisfaction of those needs is essential for a healthy functioning of the individual in different life domains, including positive work and organizational outcomes [40]. Therefore, the present study aims at using the above-mentioned theory to demonstrate how a highly inclusive climate contributes to the satisfaction of the basic human need to be autonomous, to be competent, and to belong; this, in turn, will elicit the expression of challenging (promotive and prohibitive) voice behaviors.

The Relevance of Voice
Voice is defined as a challenging, prosocial organizational citizenship behavior, aimed at improving existing organizational practices [41]. Unlike other citizenship behaviors, it is considered challenging rather than affiliative [14] because it involves speaking up with suggestions to improve the effectiveness of work routines [42] and it is targeted to higher management and supervisors who have decisional power [43,44]. Moreover, it is considered as a discretionary behavior aimed at constructive improvement rather than merely venting or criticizing [16].
This self-initiated type of input has shown to be positively related to several organizational outcomes, such as team learning [45,46], prevention of crises [47], innovation [48,49], and organizational performance [50].
In line with Van Dyne and LePine's [51] conceptualization of voice, it is possible to identify and distinguish promotive voice from prohibitive voice. The first represents a form of challenging extra-role behavior focused on changing the status quo, while being constructive in intent. Thus, it is a future-focused behavior, since employees speak up to express new ideas or suggestions for future improvement [52]; it is also considered a proactive behavior because, by proactively suggesting new ideas and improvements, it aims at achieving a better organizational state and to help its effective functioning in the long run [53].
From another perspective, prohibitive voice describes employees pointing out existing problems and practices which are perceived as harmful to the organization [52]; such a process would serve to identifying issues and correcting mistakes in a way that helps with cost reductions and process losses [53], as well as preventing or stopping harms in a more time efficient manner [52]. Despite those positive features and regardless of the existence of an established theoretical framework underlying the distinction between promotive and prohibitive voice [54], research has focused more heavily on promotive aspects of voice (e.g., [51]) or on general forms of voice considered as a unitary construct rather than a multidimensional one [54]. Besides, voice may also be risky and lead to negative consequences [55], especially the prohibitive one since it may cause negative emotions among coworkers and hurt interpersonal harmony [52]. Another consequence for pointing out problems and suggesting changes to the status quo is the negative repercussion speaking up might have on an employee's career and work relationships [42]. Employees who intend to be helpful by voicing problems and concerns may in fact be viewed as unacceptably questioning authority, causing troubles, just complaining, wasting time (e.g., [56]), or showing off and not being a team player (e.g., [57]). The judgement of potential risks and possible undesirable consequences might be one of the elements that plays a role in employees' decisions to speak up or not, together with an estimate about whether speaking up is likely to be effective [58,59]. Therefore it is not surprising that, despite the potential personal and organizational benefits associated with speaking up, employees do not seem to engage in voice often enough [60].
Based on the above premises, research is now calling for further investigation of both dimensions of voice as both are important for organizational functioning, and they might be rooted in different underlying psychological mechanisms; additionally, further research is needed to advance the comprehension of the contextual factors leading to voice behaviors in light of those mechanisms [43,61]. Such knowledge will help with understanding the conditions under which employees may be expected to speak up and what managers can do to encourage voice behaviors in the workplace [62].

Psychological Needs Satisfaction and Voice
Given the assertive and disruptive nature of voice [63], its motivational and psychological basis may be different from that used for other extra-role behaviors [14,64]. Specifically, an alternative theoretical explanation to social exchange theory might come from self-determination theory (SDT), which states that individuals are proactive and therefore tend to shape and try to optimize their own life conditions to develop their full potential and enhance the integration with the social context [65,66].
According to SDT, in order to thrive and maintain an effective and healthy level of functioning, individuals need to satisfy three basic psychological needs, specifically the needs for autonomy, for competence, and for relatedness [39,67]. Applied to a work context, the satisfaction of those needs would enhance the development of a subjective feeling of meaningfulness associated with one's work-related behaviors, as those would be perceived as congruent to one's true self [40]. The need for autonomy represents the individual's necessity to experience a sense of choice and authorship over their behavior [39]; this is viewed as the most impactful of the three needs on human motivation, and it determines the feeling of being oneself when on the job and the willingness to invest one's effort in tasks and work roles [68][69][70]. The need for competence refers to the individual's inherent desire to feel effective and confident that they can successfully interact with and adapt to new environments [39]; this leads to enhanced job performance [40]. The need for relatedness is defined as the individual's propensity to feel connected to others, which in the workplace means establishing and maintaining valuable interpersonal relationships with co-workers, feeling one is an active part of a group, and developing positive emotions because of those bonds [39,67].
The satisfaction of those psychological needs has been demonstrated to be an energetic driver of OCB (e.g., [71,72]). In fact, according to SDT, extra-role behaviors require individuals to put in an effort beyond the official demands of the job; hence, individuals need to be intrinsically motivated in order to engage in those behaviors [73]. Moreover, because of their intrinsic motivation, those individuals seek to undertake meaningful tasks which give them a sense of contributing to the broader community [74,75]; this, in turn, would lead to increased OCB, especially the change-oriented type, as employees would tend to expand their attention towards seeking new ways of doing things, challenging current work methods and discovering new solutions to problems [68,76].
While the relationship between needs satisfaction and affiliative OCB has been well established, especially in the form of helping behaviors and being respectful towards organizational rules and regulations (e.g., [77,78]), there are fewer studies exploring the relationship between needs satisfaction and voice behaviors.
Regardless, given the challenging and change-oriented nature of voice, employees who perceive to be free to act and decide (satisfaction of the need for autonomy), to be effective in performing their roles (satisfaction of the need for competence) and to be a valued part of a collective entity (satisfaction of the need for relatedness) are expected to proactively seek opportunities to participate in organizational matters such as voice [79,80].

The Relationship between Inclusion, Psychological Needs Satisfaction and Voice
As emphasized earlier, since the effective management of diversity goes beyond legal compliance [23], the constructs of inclusion and employee perceptions of inclusiveness become more and more important.
Inclusion can be defined as the employee's perceptions of being a valued member of the workgroup through the satisfaction of their need for uniqueness and belongingness within the workplace [4]. Moreover, a climate for inclusion is realized when "policies, procedures, and actions of organizational agents are consistent with fair treatment of all social groups" [4] (p. 1277), especially those traditionally disfavored and belonging to minorities.
There is an established relationship between diversity and inclusion [81]; namely, employees can feel excluded from some important organizational processes because of their actual or perceived membership in a minority or disfavored identity group [82,83]. However, a climate for inclusion has shown to be broader in scope because it requires going beyond the focus on managing the organizational demography [5]. More specifically, a perception of inclusiveness refers to the actual and meaningful involvement of workers in the core organizational processes of decision-making, communication networks and social-formal and informal-activities [84]. Therefore, an inclusive climate cannot be limited to the moral imperative of ensuring justice and fair treatment (i.e., providing equal opportunities in hiring and promotion), but it refers to "a person's ability to contribute fully and effectively to an organization" [85] (p. 215).
As previously mentioned, scholars have worked to establish the contextual antecedents of voice (e.g., [51,86]). According to the social information processing (SIP) theory [87], the workplace social context has an impact on employee perceptions of what is considered acceptable in terms of behavior [88]; since employees interpret their environment through social interactions with the intent of making sense of it, they develop perceptions regarding whether or not their workplace is a favorable one for speaking up [89], and they use these perceptions to guide their behavior [90,91].
Certain elements of the organizational context have been demonstrated to lead to voice behaviors, and those elements have shown some similarities with the construct of inclusion, such as a highly supportive climate [34], a fair workplace [49], an ethical leadership style based on encouraging employees to express their concerns [92,93], and acting as ethical role models [94].
Further research has underlined the role of organizational culture and climate [34,89,95], by pointing out how a conservative and exclusive organizational culture can be perceived as unfavorable towards issue-selling [91], and how a participative climate should be positively linked to beneficial employee voice behaviors [96]. The underlying rationale is that a participative climate (such as an inclusive climate), would be aimed at involving and supporting employees [97]; therefore, when they are invited to voice legitimate ideas and concerns, they perceive that speaking up is valued and that there are fewer risks associated with dissenting from the status quo [56,98].
As introduced earlier, self-determination theory gives an important contribution to the explanation of the mechanisms through which inclusion can influence voice behaviors; despite basic psychological needs that can be viewed as universal-meaning that individual dispositional differences exist in terms of strength of needs-it is the extent to which those needs are satisfied, rather than their strength, that impacts humans' growth, integrity and well-being [65,68]. Research has demonstrated that the organizational environment has a crucial role in the satisfaction of basic psychological needs, thus impacting the individual's functioning [39]. Accordingly, satisfaction of those needs is strictly dependent on the quality of the organizational social context [99] and, in turn, it is considered to be an antecedent of work performance [100]. From this perspective, work climate is a critical predictor of needs satisfaction [101], since it is based on the employees' perceptions regarding the ways they are treated [102]. More specifically, working environments that are highly supportive at the managerial level, namely those where the supervisor acknowledges employees' perspectives, provides meaningful information and offer opportunities for decision making and self-initiation [103], are the ones that facilitate needs satisfaction. It is evident how those elements of a supportive work environment fit in with the construct of inclusion climate, one in which the underlying focal point pertains to an employee's involvement in work groups, participation in the decision-making process, and access to information and resources [104]. Therefore, a climate supportive of an individual's true self will be positively linked to needs satisfaction [39], whereas a rigid and tense social climate will impede need satisfaction and thwart growth, functioning and wellbeing [40].
Most importantly, only a few studies have focused on the relationship between inclusion, needs satisfaction, and voice. They have found that an inclusive leadership behavior, one that nurtures a sense of openness, availability, and belongingness, leads to the satisfaction of followers' needs [105,106], and that this fulfilment has a central role between inclusion and voice. This is because, in order to engage in voice behavior, one should believe his/her action and inputs will be effective (competence), and they should feel safe enough about their group membership to speak up (relatedness) [107]. Moreover, the sense of independence in freely choosing to initiate an action at work (autonomy) would elicit a motivation to engage in more conscientious behaviors that help preserve and support the growth and advancement of the organization [68].
Therefore, based on these investigations, we expect the following: Hypotheses 1 (H1a). Basic psychological needs satisfaction will mediate the relationship between inclusion climate and promotive voice.

Hypotheses 1 (H1b).
Basic psychological needs satisfaction will mediate the relationship between inclusion climate and prohibitive voice.

Sample
The sample was composed by 425 workers (53% female) of an international company focused on development, property management and leasing of shopping centres. Of these, 58% were 30-49 years of age and 88% had completed a university degree. Participants were from different countries: Portugal (61%), Spain (15%), Germany (10%), Italy (9%), Romania (3%), and Greece (2%). Most of the participants worked in the central offices of the company (68%), mainly on a permanent contract (87%). Regarding the job function, 40% were team members, 18% team leaders, 16% managers, 14% project team specialists, 11% senior managers, and 2% executives. The contract term was full-time for 99% of the workers.

Inclusion Climate
Inclusion climate was assessed using the subscale "Inclusion" of the Mor Barak et al. [83] Diversity Climate Scale in its shorter version [108]. Three items were used to measure the inclusion climate at the management level (e.g., "Management here encourages the formation of employee network support groups"). Each item was answered on a 5-point ordinal scale (from 1 = "strongly disagree" to 5 = "strongly agree").

Basic Needs
Basic needs were assessed using a short version of the Basic Needs Satisfaction in General Scale [39,109]; ten items were used to assess the satisfaction of the needs for autonomy (e.g., "I am free to express my ideas and opinions on the job"), competence (e.g., "I have been able to learn interesting new skills on my job") and relatedness (e.g., "I consider the people I work with to be my friends"). Each item was answered on a five-point ordinal scale (from 1 = "strongly disagree" to 5 = "strongly agree").

Promotive Voice and Prohibitive Voice
Promotive and prohibitive voice was assessed using a reduced version of Liang et al.'s [52] Voice Behavior Scale, comprising six items to be answered on a five-point Likert scale (from 1 = "strongly disagree" to 5 = "strongly agree"), three for promotive voice (e.g., "Make constructive suggestions to improve the unit's operation") and three for prohibitive voice (e.g., "Speak up honestly with problems that might cause serious loss to the work unit, even when/though dissenting opinions exist").

Procedure
Participants completed an individual and anonymous questionnaire including the above-mentioned measures and some sociodemographic and career questions (i.e., workplace, academic level, country, functional level, contract type, contract term, gender and age). The study was conducted in accordance with the Declaration of Helsinki. Information regarding the study was provided to all subjects at the beginning of the questionnaire. The informed consent was firstly presented to all participants, and their agreement was necessary to continue with the voluntary participation. They were also informed that they could withdraw at any time.

Data Analysis
To conduct the statistical analysis, the software R [110] through the integrated development environment RStudio [111] was used. An α = 0.05 (Type I error) was considered for all analyses. The skimr package [112] was utilized to produce the descriptive statistics. The skewness (sk) using the "sample" method (i.e., sample skewness of the distribution) and the kurtosis (ku) using the "sample excess" method (i.e., sample kurtosis of the distribution with a value of 3 being subtracted) were calculated using the PerformanceAnalytics package [113]. The coefficient of variation (CV) was estimated with the sjstats package [114], and the standard error of the mean (SEM) was calculated with the plotrix package [115]. The mode was computed by the modeest package [116]. Absolute values of ku smaller than seven and sk smaller than three were assumed to be indicative of no severe violations of the univariate normality [117,118].
To obtain evidence about the originally proposed dimensionality of the measurement models, confirmatory factor analysis (CFA) was used. The following goodness-of-fit indices were used: TLI (Tucker-Lewis Index), NFI (Normed Fit Index), SRMR (Standardized Root Mean Square Residual), CFI (Comparative Fit Index), RMSEA (Root Mean Square Error of Approximation), and χ 2 (df) (Chi-Square statistic and Degrees of Freedom). Estimates above 0.95 are considered acceptable for CFI, NFI, and TLI, whereas estimates smaller than five are considered acceptable for χ 2 /df [119]. Values below 0.08 are expected for RMSEA, and SRMR [120].
The package lavaan [121] was used to run the CFA analysis using the WLSMV (Weighted Least Squares Means and Variances) estimator [122]. The WLSMV was chosen because it does not require multivariate normality as an assumption and because all items of the psychometric instruments used have an ordinal response scale.
The Average Variance Extracted (AVE) was estimated to test the evidence for convergent validity in terms of internal structure [123]. Satisfactory convergent validity evidence in terms of the internal structure was assumed for AVE ≥ 0.5 [124].
To assess the reliability of first-order factors, the following estimates of internal consistency were used: α ordinal [125] and ω [126]. Values of α ordinal ≥ 0.7 and ω ≥ 0.7 are considered indicative of acceptable reliability evidence. To assess the internal consistency of the second-order latent factors, the proportion of variance explained by second-order factor after partialling the uniqueness of the first-order factor (ω partialL1 ), the proportion of the second-order factor explaining the total score (ω L1 ), and the variance of the first-order factors explained by the second-order factor (ω L2 ) were used. Both second-order and first-order internal consistency estimates were calculated using the semTools package [127].
The structural model (i.e., full structural equation model) was tested using the lavaan package [121] to test validity based on relationships with other constructs. In the CFA as in the full structural equation model, listwise deletion was implemented (i.e., only the cases with complete data for all variables in the analysis are included). The total, direct and indirect effects were reported with a 95% confidence interval.

Results
To test the hypotheses within the proposed model, a two-step approach was used [117]. First, the measurement model was tested through a CFA, and afterwards the structural model (with all the hypothesized regression paths) was tested. Both models were tested using only the subjects with complete observations for the used measures (n = 246).

Items' Distributional Properties
The distributional properties of the measurement model indicators are presented in Table 1. Various summary measures, together with kurtosis (ku), skewness (sk) and a histogram were used to analyze the psychometric sensitivity and distributional properties of each item. None of the items presented values indicative of severe violations of the univariate normality, since all |ku| < 7 and |sk| < 3 [117,118].

Dimensionality
The measurement model was based on three measures: Inclusion Climate (one firstorder factor), Basic Needs Satisfaction (one second-order factor with three first-order factors) and Voice Behavior Scale (two first-order factors). Regarding the Basic Needs Satisfaction scale, it was required to constrain the residual variance of the first-order factor satisfaction of the needs for autonomy to 0.01, to avoid negative variance.
The measurement model (with the three measures) presented good fit to the data (χ 2 (144) Table 2 presents the latent correlations among the used variables.

Structural Model
The structural model presented a good fit to the data (χ 2 (144) Table 3 presents the structural model regression paths (direct effects) as well as the indirect and total effects. The model explained 28% of the basic needs satisfaction variance (r 2 BN = 0.277), 12% of promotive voice variance (r 2 PromV = 0.122) and 21% of prohibitive voice variance (r 2 ProhV = 0.214). It should be noted that all direct effects were statistically significant, with both inclusion climate and basic needs satisfaction presenting stronger effects on prohibitive voice rather than on promotive voice.
Both tested indirect effects were statistically significant (p < 0.001), being the standardized effect higher for prohibitive voice (β ProhV ← BN ← IC = 0.286) rather than for promotive voice (β PromV ← BN ← IC = 0.215). However, the total effects were not statistically significant, presenting standardized regression paths near to zero. Some authors call it a suppression or inconsistent mediation [128].

Discussion
Organizational citizenship behavior (OCB) is central for the survival of modern businesses [129]. However, and with specific reference to the challenging nature of some OCB such as voice behavior, it can be risky for individuals and therefore only flourishes in certain contexts [42]. The literature has shown that, in general, perceived diversity management and inclusion are positively linked to OCB [130,131]; nevertheless, previous studies have either mainly focused on the affiliative type of OCB (such as helping behaviors) (e.g., [132]) and/or they have relied on social-exchange theory as the only mechanism to explain the relationship between an organization's context for diversity and inclusion and what its employees give back in terms of OCB [133].
The present study filled the gap in existing research by investigating the contribution of self-determination theory in explaining the impact of inclusion climate on promotive and prohibitive voice.
Specifically, the analysis performed revealed that the satisfaction of needs for autonomy, competence and relatedness partially mediated the relationship between inclusion climate and promotive and prohibitive voice, therefore supporting our Hypotheses 1a and 1b.
The findings can be interpreted in line with the small amount of existing literature on the topic; specifically, a work climate that is supportive of and validating one's true self (as an inclusive climate is) would elicit an organization's ability to satisfy its employees' basic psychological needs [39]. In turn, the employees' enhanced feeling of fulfilment in independently initiating action at work (autonomy), effectively mastering work activities and being confident about possessing the required skills (competence), as well as being part of an in-group based on meaningful relationships (relatedness), would lead them to engage in proactive discretionary behaviors aimed at challenging the work processes with the intention to improve them [107].
On a separate note, it is important to highlight that the satisfaction of basic psychological needs only partially mediated the relationship between climate for inclusion and voice behaviors and that the indirect effect mentioned above was stronger for prohibitive voice rather than for promotive voice. This means that other mechanisms should also be taken into consideration when trying to explain how inclusion/exclusion impacts challenging OCB and that especially for promotive voice, other factors might have an important role. For example, some individual and personality differences can affect motivation to engage in those behaviors [134]. Therefore, future research should take them into account.
Our results represent an element of novelty compared to the existing literature, as they show that the impact of inclusion on voice is more complex than expected; specifically, the direct effect of inclusion climate on both promotive and prohibitive voice is negative, whereas its indirect effect on both voice behaviors through needs satisfaction becomes positive. There could be several explanations for such phenomenon. First, as briefly mentioned earlier, there are some individual and personality attributes which have been demonstrated to have a distal influence on voice. One such personality factor is core self-evaluations (CSE), which describes the core self-concepts that individuals hold about themselves [134]. The main attributes of CSE, such as generalized self-efficacy, locus of control, emotional stability, and self-esteem, reflect human agency or a predisposition to interact with the environment [134]. Individuals who are high in CSE consider themselves as efficacious in facing challenges and they perceive themselves as having control over their work environment, therefore leading to a higher approach motivation; such motivation is the drive to explore ways to improve organizational processes and it has been proven to lead to higher engagement in voice behavior as a way of seeking growth [135]. On the contrary, low CSE would be linked more to an avoidance motivation, which entails a focus on security needs and prevention of negative outcomes; therefore, individuals high in avoidance motivation will tend to act cautiously and work diligently to accomplish their prescribed roles and duties, being careful to avoid anything that could threaten their job security or lead to any other potentially negative outcome, such as challenging the status quo through speaking up [134]. Those individuals may have internalized organizational behavioral expectations and are therefore unlikely to challenge the status quo [136]. This could explain why in our study inclusion climate alone would lead to lower promotive and prohibitive voice; in fact it is likely that some other personality factors not considered in the present research accounted for those results, and those could also explain the partial (not full) mediation through need satisfaction. Having an individual tendency to avoid any challenge with the aim of preserving harmony and security could interact with a work climate where there are already some positive initiatives around inclusion, therefore eliciting in the employees a sense of obligation not to show ungratefulness towards management, nor to make trouble by suggesting time consuming changes.
This can also be linked to the second explanation, in that change is not always popular and it is not always perceived positively from supervisors; for instance, a change could challenge the status quo resulting in a different power structure, and supervisors might not want that [54]. This is even truer for prohibitive voice, since supervisors might consider the challenging behavior as a manifestation of rebellion and complaint [44]. Furthermore, it can lead to negative consequences such as poor performance ratings given to subordinates [55], thus impacting coworkers as well. As noted by Morrison and Milliken [137], organizations can develop climates around speaking up or not speaking up and, according to existing research on climate [138], such shared beliefs and social norms also emerge at the work group/work unit level, and they have a strong effect on behavior [34].
The unpopularity of change as linked to questioning the power structure also seemed to be particularly relevant in cultural contexts characterized by a high power distance and where face-saving is emphasized [139,140]; in fact our sample is characterized by employees from countries with a moderate/moderately high power distance (i.e., Portugal, Spain, Italy, Romania; https://hi.hofstede-insights.com/national-culture, accessed on 8 June 2021).
An additional explanation for our results could rely on the fact that the inclusion climate measurement used in the present study refers to the inclusiveness implemented by the higher management; therefore, and in line with what was already discussed in this section, it is possible that employees do not want to risk being misunderstood or experiencing other undesirable social consequences within their everyday working groups (at a lower organizational level); in particular, they might not want to have their good intentions misinterpreted as "bossiness, unsolicited interference, and an effort to undermine the credibility" of their peer colleagues and supervisors [141] (p. 457). Hence, it would make sense that only when individuals feel safe enough in terms of not having their positive relationships and the belongingness to their in-group threatened, feeling valued in their unique contribution (not losing their face) and satisfying their personal volition in being impactful and self-determining in the workplace-namely, having their fundamental needs fulfilled-will they engage in both promotive and prohibitive voice.
The present findings reinforce the uniqueness of voice compared to other OCBs; by definition, voice involves speaking up with suggestions for change. This requires more formal decisionmaking and resource allocation power than the speaker possesses. If it did not, there would be little reason to speak up rather than simply taking action by oneself [41].

Limitations, Implications and Future Research
Our findings must be interpreted in light of some limitations. One limitation is common method bias, based on the reliance on self-report data only [142]. However, the literature has underlined how self-report is the only valid measure of basic psychological needs satisfaction [143]. Additionally, findings from meta-analytic studies have strongly encouraged the use of self-reported measures of OCB [144].
A second limitation is the cross-sectional design of the study, which would not allow to test causality. Thus, we could only claim indirect relationships between the variables (e.g., [145]), grounded in self-determination theory. Such a strong theoretical foundation should help to counteract the lack of time-lagged data collection [128]; nevertheless, longitudinal research designs are needed to better investigate the relationship between psychological factors and voice behavior over a period of time.
Finally, future research about organizational climate should also consider the possibility of multilevel design by aggregating data at the group level of analysis [148], considering the simultaneous influence of inclusion climate at different levels, for instance at the management level, but also at the supervisor and at the peer levels. This implies that three inclusion climates should be considered: the one generated at the higher management level, the one generated at the supervisor's level (who transforms those management policies and procedures into daily practices), and the one generated within the group of coworkers, considering the influence of social norms on behavior [149]. This would help identify how a group-level process (i.e., inclusion climate) can influence another process at the individual level (basic needs satisfaction and individual voice behavior).
Despite the above limitations, the present study makes some important theoretical and practical contributions. Firstly, it laid on self-determination theory [39] to test a model of prosociality as fueled by the satisfaction of core psychological needs [150,151]; this process is based on intrinsic rather than extrinsic motivation, and it is consistent with the intrinsic motivational nature of psychological empowerment in that empowered employees feel more able to affect change at work [152]. Therefore, those results differ from and extend previous studies using the predictions of social exchange theory [22].
Secondly, our findings integrate the examination of psychological factors determining voice behavior with the role of context, aligning with existing research that addresses how environmental factors together with individual differences can affect the motivation to engage in OCB [143]. In fact, work climates that are need supportive are labeled within SDT, as autonomy-supportive social contexts [153]. Those environments are characterized by a management style that, amongst other things, consistently supports and acknowledges employees' perspective, provides greater choice encouraging self-initiation, and is genuinely concerned about and respectful of all employees [68]. These components are directly related to the fulfillment of the three basic psychological needs [154], as they make the employee feel competent in that his/her opinions matter, and they feel connected with the manager and experience greater volition [153]. Moreover, they also elicit a sense of being an active part of the organization, enhancing their sense of inclusion and participation in organizational life.
Thirdly, the current study supports previous research findings about the need to adopt a bidimensional conceptualization of voice because the act of speaking up can be done for distinct reasons and they might have different effects on the organization [54].
Our findings also provide insight into what organizations can do to encourage employee voice; for example, higher management should, amongst other things, facilitate the formation of employee network support groups by investing adequate resources in these types of initiatives and taking seriously the viewpoints of minorities, and acting on the basis of those ideas and opinions (i.e., with follow-up actions to address them or explanations for not doing so). For instance, it is fundamental for existing diversity to be recognized and to take consequent measures to integrate those differences in decisionmaking and career and development processes [155]. Nevertheless, our study demonstrated that the sole application of inclusive policies is not enough; as a matter of fact, although management have the best intentions for encouraging voice, employees often remain uncomfortable about speaking up [56,90]. This means that higher management should also consider how some psychological factors can help or dissuade employees from voicing, and that those factors can be influenced by the organizational context; specifically, voice can be maximized to the extent that employees feel they are given choice and encouragement for personal initiative, that their opinion is valuable, and that their relationship with colleagues is not at risk.
Basic needs satisfaction plays a key role in linking an inclusive context to voice and to develop an individual's autonomous/intrinsic motivation as opposed to a controlled/extrinsic one [109]. Such a motivation is fundamental for businesses who want speaking up to be the routine, as only employees who are intrinsically motivated will perform voice behaviors, and the present research has provided empirical support to the contextual conditions that help with satisfying those needs. Additionally, considering the impact of the proximal social context and the influence of social norms on the individual behavior, senior management should also consider how a truly inclusive culture, one that guarantees the fulfilment of the individual's basic psychological needs, cannot be developed without the help of direct supervisors and of coworkers and colleagues. Therefore, initiatives should not only be implemented at the top level (i.e., open door policy, employees' representative joining consultative committees, quality circles, and having a seat at leadership tables) [107], but also by developing training and coaching programs involving front-line supervisors and workgroups where possible, to experiment in a safe environment how to facilitate voice in ways that enhance people's feelings of being unique, competent and yet valued members of their workgroup.

Conclusions
By recognizing that the ideas and knowledge fundamental to improve and innovate organizational processes do not necessarily follow a top-down unidirectional approach, that they are based on the distinctive value each employee brings to the organization rather than on his/her position in the organizational hierarchy, businesses will create a benefit that goes beyond a short-term economic advantage, therefore contributing to the development of sustainable organizations in the long term.