Christian Vandenberghe

Marie-Colombe Afota
email: marie-colombe.afota@hec.ca.

Ariane Ollier-Malaterre

How supervisors set the tone for long hours: Vicarious learning, subordinates' self-motives and the contagion of working hours

Keywords: Long Working Hours, Social Contagion, Vicarious Learning, Supervisor-subordinate Dyad, Self-Motives

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Introduction

Global indicators suggest that in the last century, working time has been decreasing in all developed countries [START_REF] Lee | Working time around the world: Trends in working hours, laws and policies in a global comparative perspective[END_REF]. However, this overall pattern masks a large variability across groups of workers. Actually, the share of individuals who are working very long (i.e., above 50 hours a week) hours has been on the increase in the last decades [START_REF] Golden | A brief history of long work time and the contemporary sources of overwork[END_REF]. There is accumulating evidence that a substantial proportion of workers continue to put in long work hours (e.g., [START_REF] Angrave | What is the relationship between long working hours, over-employment, under-employment and the subjective well-being of workers? Longitudinal evidence from the UK[END_REF][START_REF] Golden | A brief history of long work time and the contemporary sources of overwork[END_REF]. In fact, there seems to be a significant mismatch between workers' ideal working hours and their actual working hours. In the United States, the proportion of overemployed workers -that is, workers who work more hours than they wish -has been estimated to vary between 6% and 50%, depending on the categories of workers [START_REF] Golden | Overemployment mismatches: The preference for fewer working hours[END_REF].

A puzzling question therefore arises: Why do some people work long hours when they seem to resent it? Several explanations have been offered in the literature, among which is social contagion [START_REF] Brett | Working 61 plus hours a week: why do managers do it[END_REF][START_REF] Cowling | Still at work? An empirical test of competing theories of long hours culture[END_REF][START_REF] Kodz | Breaking the long-hours culture[END_REF].

Social contagion occurs when an individual's behavior changes as a result of interactions with others (Latané, 2000). Although several studies have found support for a social contagion effect of working hours [START_REF] Brett | Working 61 plus hours a week: why do managers do it[END_REF][START_REF] Cowling | Still at work? An empirical test of competing theories of long hours culture[END_REF][START_REF] Eastman | Working for position: Women, men, and managerial working hours[END_REF][START_REF] Kodz | Breaking the long-hours culture[END_REF][START_REF] Landers | Rat race redux: Adverse selection in the determination of working hours in law firms[END_REF], to the best of our knowledge there has been only one empirical study that has demonstrated the role of the immediate supervisor in shaping subordinates' working hours [START_REF] Zhang | Held captive in the office: an investigation into long working hours among Korean employees[END_REF]. Supervisors are key agents who influence subordinates' behaviors, such as ethical behaviors [START_REF] Falkenberg | Ethical behaviours in organizations: Directed by the formal or informal systems[END_REF][START_REF] Grojean | Leaders, values, and organizational climate: Examining leadership strategies for establishing an organizational climate regarding ethics[END_REF], safety behaviors (Simard & Marchand, 1994;[START_REF] Weber | The front-line supervisor's role in safety[END_REF], and organizational citizenship behaviors [START_REF] Yaffe | Leading by example: the case of leader OCB[END_REF]. [START_REF] Regan | Beware the work/family culture shock[END_REF] argued that supervisors are in a critical position to change long-hour norms [START_REF] Blair-Loy | Competing devotions: Career and family among executive women[END_REF][START_REF] Gascoigne | Extreme work, gendered work? How extreme jobs and the discourse of 'personal choice' perpetuate gender inequality[END_REF] and suggested that leaders' own behaviors are important for such a change. However, the mechanisms underlying such influence are poorly understood [START_REF] Zhang | Held captive in the office: an investigation into long working hours among Korean employees[END_REF]. If supervisors are indeed in a central position to change the working-hours norm, it is particularly important to go beyond the acknowledgement of this relationship and theorize why and under what conditions supervisors' behaviors contribute to shape subordinates' long working hours.

In this paper, we examine the processes by which newcomers may imitate their supervisor's working hours during socialization. Specifically, we identify social contagion as a process that may explain employees' voluntary engagement in working long hours in the absence of mandated overtime or excessive workload. Therefore, we focus on the many employees who have some leeway to adjust their working hours (typically, exempt employees), that is, the average number of hours they spend working per week. Employees who have this leeway may consciously or unconsciously imitate their supervisor's working hours through role modeling.

We adopt a motivational perspective and build on social learning theory [START_REF] Bandura | Social learning theory[END_REF][START_REF] Bandura | Social foundations of thought and action: A social cognitive theory[END_REF] to account for the contagion of long working hours from supervisors to subordinates.

Social learning theory provides a relevant framework to account for working hours contagion because learning -particularly vicarious learning or modeling (i.e., learning through the observation of others' behaviors) -is a key process by which individuals change behaviors in organizational contexts [START_REF] Manz | Vicarious learning: The influence of modeling on organizational behavior[END_REF]. Using the tenets of social learning theory, we propose that subordinates engage in vicarious learning based on the perceived desirability of the expected outcomes associated with imitating their supervisor's working hours (e.g., status, promotion, etc.). We further argue that imitation desirability is influenced by four factors-the perceived status of the supervisor, the subordinate's work centrality, the congruence between organizational norms and supervisor working hours, and the strength of subordinate identification with the supervisor. We view the weight of these factors as a function of the subordinate's self-motives (e.g., self-enhancement, self-verification, belongingness, and selfimprovement).

Because leader-member exchange (LMX) plays an important role in the socialization process within the supervisor-subordinate dyad (Sluss & Thompson, 2012), we argue that the stage of LMX development is likely to have a critical role in the evolution of our model over time. We therefore begin by analyzing the long hours contagion processes during the role-taking stage (i.e., when the subordinate has not yet established a stable relationship with the supervisor; [START_REF] Graen | Toward a psychology of dyadic organizing[END_REF], and then discuss how the weight of the factors influencing imitation desirability changes when the supervisor-subordinate relationship evolves from the role-taking to the routinization stage [START_REF] Graen | Toward a psychology of dyadic organizing[END_REF].

Our paper answers calls for a better understanding of the antecedents of working hour behaviors [START_REF] Major | Work time, work interference with family, and psychological distress[END_REF], the practices influencing work-life balance [START_REF] Kossek | Workplace social support and work-family conflict: A meta analysis clarifying the influence of general and workfamily specific supervisor and organizational support[END_REF][START_REF] Mccarthy | Work-life balance policy and practice: Understanding line manager attitudes and behaviors[END_REF], and the role of modeling in behavior contagion within leader-subordinate dyads (ten [START_REF] Brummelhuis | Does family life help to be a better leader? A closer look at crossover processes from leaders to followers[END_REF].

As such, our model makes several contributions. First, it adds to the social learning literature [START_REF] Bandura | Social learning theory[END_REF] by delving into the motivational processes behind social learning, which have mainly been addressed through expected rewards and/or punishments. We argue that the subordinate's self-motives are key boundary conditions for vicarious learning and act as motivational factors for social learning. Second, our model contributes to the literature on behavioral contagion by clarifying its underlying mechanisms. Although role modeling has been argued to explain behavioral contagion in the workplace (e.g., [START_REF] Bommer | Does one good turn deserve another? coworker influences on employee citizenship[END_REF][START_REF] Mayer | Who displays ethical leadership, and why does it matter? An examination of antecedents and consequences of ethical leadership[END_REF][START_REF] Robinson | Monkey see, monkey do: The influence of work groups on the antisocial behavior of employees[END_REF], our model combines vicarious learning with imitation desirability to delineate the conditions under which subordinates will likely mimic the leader's working hours. Third, we contribute to the family supportive supervisory behaviors (FSSB) literature by describing how the supervisor's role modeling behaviors, a central component of family supportive behaviors [START_REF] Hammer | Clarifying the construct of family-supportive supervisory behaviors (FSSB): A multilevel perspective[END_REF], influence subordinates' working hours. In so doing, we emphasize the role of subordinates in the role modeling process. Lastly, by identifying the supervisor's working hours as a predictor of the subordinate's working hours, our model helps understand the factors influencing employees' heavy work investment 1 (Snir & Harpaz, 2012). This paper is organized as follows. We first review how the vicarious learning literature can be useful to understand the contagion of working hours. Next, we present our model in the context of the role-taking stage of the supervisor-subordinate relationship and elaborate on its associated propositions. We then discuss how the routinization of the supervisor-subordinate relationship affects our model over time. We conclude with theoretical and practical implications as well as avenues for future research.

Vicarious Learning Regarding Working Hours

Social learning theory pinpoints the influence of role models in shaping individuals' behaviors in organizational settings [START_REF] Bandura | Social learning theory[END_REF]. Because supervisors personify organizational norms and values [START_REF] Burke | Organizational culture: A key to the success of work-life integration[END_REF][START_REF] Scandura | Relationships of gender, family responsibility and flexible working hours to organizational commitment and job satisfaction[END_REF], they constitute role models for their subordinates. Indeed, supervisors'behaviors have been shown to significantly influence subordinates' behaviors (e.g., [START_REF] Jaussi | Leading for creativity: The role of unconventional leader behavior[END_REF][START_REF] Potters | Leading-by-example and signaling in voluntary contribution games: an experimental study[END_REF][START_REF] Yaffe | Leading by example: the case of leader OCB[END_REF]. Moreover, several leadership theories, particularly authentic leadership and ethical leadership theories, are grounded in the pivotal position of supervisors as role models (Avolio & Gardner, 2005;[START_REF] Manz | Self-management as a substitute for leadership: A social learning theory perspective[END_REF]Trevino & Brown, 2005).

Evidence for subordinates engaging in vicarious learning of supervisory working hours is scarce. In a sample of Korean supervisor-subordinate dyads, [START_REF] Zhang | Held captive in the office: an investigation into long working hours among Korean employees[END_REF] reported a positive association between supervisors' and subordinates' working hours. [START_REF] Kirby | The policy exists but you can't really use it": communication and the structuration of work-family policies[END_REF] observed that subordinates consider their supervisors' behaviors, including their overtime hours, when deciding to use or not work-family benefits. In the same vein, [START_REF] Hammer | Development and validation of a multidimensional measure of family supportive supervisor behaviors (FSSB)[END_REF] reported that subordinates perceive their supervisors as role models in regard to work-life balance. Similarly, [START_REF] Koch | Setting a good example: Supervisors as work-life-friendly role models within the context of boundary management[END_REF] found that role modeling mediated the positive association between supervisors' and subordinates' segmentation of the work and life domains. However, little is known about why and under what conditions subordinates imitate their supervisors' working hours.

A closer look at the socialization and social learning literature helps to form a clearer picture of the plausible mechanisms at play in the role-taking stage of the supervisor-subordinate relationship. When a newcomer joins an organization, a socialization process takes place [START_REF] Van Maanen | Towards a theory of organizational socialization[END_REF]. During this process, the newcomer learns the "ropes," which includes internalization of tacit rules [START_REF] Van Maanen | Towards a theory of organizational socialization[END_REF], such as norms for working hours (Feldman, 2002). Because of the power asymmetry in the leader-subordinate dyad and because supervisors have frequent interactions with subordinates, they constitute privileged models for learning during the socialization process (Sluss & Thompson, 2012;Weiss, 1977).

However, not all subordinates are likely to adopt their supervisor's behaviors. The idea of vicarious learning (1977,1986), which is at the core of Bandura's social learning theory (1977,1986), is useful to understand why some subordinates mimic their supervisor's behaviors and others do not. Vicarious learning describes the process by which an individual begins to adopt behaviors through the observation of relevant models. The motivation to perform the behavior is a central aspect of vicarious learning, as an individual will mimic a model's behavior only if s/he observes that the model's behavior brings positive outcomes (i.e., rewards) to the model [START_REF] Bandura | Social learning theory[END_REF]. Positive outcomes increase the likelihood that a behavior is adopted while negative outcomes (i.e., punishments) decrease that likelihood [START_REF] Manz | Vicarious learning: The influence of modeling on organizational behavior[END_REF]. Vicarious learning is likely salient during the socialization process because the employee seeks to learn the behaviors appropriate to his/her role without incurring the cost of trials and errors [START_REF] Bandura | Social foundations of thought and action: A social cognitive theory[END_REF].

Based on the above considerations, we propose that the subordinate's perception of the desirability of imitating the supervisor's working hours constitutes a central aspect that motivates the subordinate to adopt the supervisor's working hours. We define imitation desirability as the extent to which the subordinate expects that imitating the supervisor's working hours will lead to positive outcomes (e.g., career advancement, salary increase, positive reputation). In other words, imitation desirability captures the valence, in the eyes of the subordinate, of the consequences of adopting the supervisor's working hours in terms of associated rewards and punishments. Although subordinates may anticipate a mix of positive and negative consequences, social learning theory postulates that individuals will be motivated to imitate a behavior if the perceived rewards exceed the perceived punishments [START_REF] Bandura | Social learning theory[END_REF]. We therefore conceptualize imitation desirability as an overall assessment ranging from extremely undesirable to extremely desirable. Based on the above ideas, we propose that imitation desirability is a key cognitive process that underlies vicarious learning:

P1. The relationship between a supervisor's long working hours and his or her subordinate's long working hours is moderated by the desirability of imitating the supervisor's long working hours, as perceived by the subordinate. The more (less) desirable the subordinate perceives the imitation to be, the more (less) likely s/he is to adopt the supervisor's long working hours.

We now turn to the mechanisms that influence imitation desirability in the role-taking stage of the LMX relationship. Drawing upon role theory, LMX theory describes the development of the subordinate-supervisor relationship as a process involving three stages: role-taking, rolemaking, and role-routinization, respectively [START_REF] Graen | Toward a psychology of dyadic organizing[END_REF]. In the role-taking stage, the supervisor initiates a series of role episodes during which s/he learns the subordinate's skills and motivation levers by communicating role expectations and assessing the subordinate's responses. In the role-making stage, members gauge each other's responses against role expectations. This process eventually leads to the role-routinization stage where the quality of the relationship between the dyadic members stabilizes [START_REF] Graen | Toward a psychology of dyadic organizing[END_REF]. Working hours are likely established early in the socialization process because appropriate working hours are often implicit, and therefore from day one newcomers make decisions about when to leave the office and when to show up the next morning. We therefore place a greater emphasis on the articulation of the mechanisms of working hours' contagion during role-taking. We later analyze how these processes evolve when the LMX relationship stabilizes.

Antecedents of Imitation Desirability in the Role-Taking Stage

A central idea in social learning theory is that the decision to engage in a behavior depends on outcome expectations. In the case of vicarious learning, these expectations derive from two sources: vicarious reinforcements and self-reinforcements [START_REF] Bandura | Social learning theory[END_REF][START_REF] Manz | Vicarious learning: The influence of modeling on organizational behavior[END_REF].

Vicarious reinforcements refer to the extent to which the observer perceives that a given model is punished vs. rewarded for his or her behaviors. Such reinforcements serve two purposes: they inform the observer of the appropriate behaviors in a given context, and they have motivational effects because they signal that observers may receive similar rewards if they engage in these behaviors [START_REF] Bandura | Social learning theory[END_REF]. Self-reinforcements refer to the observer's own valuation of the behavior. When the observer values a behavior, s/he will be motivated to display it because the self-satisfaction resulting from displaying the behavior is self-rewarding. While both externally rewarded and internally valued outcomes are likely to increase the individual's willingness to engage in vicarious learning [START_REF] Bandura | Social foundations of thought and action: A social cognitive theory[END_REF][START_REF] Manz | Vicarious learning: The influence of modeling on organizational behavior[END_REF]Weiss, 1977), they are not necessarily aligned. For example, nurses who spend time socializing with patients may be punished if organizations view this as wasted time, yet they may continue to value this behavior.

In addition to vicarious reinforcements and self-reinforcements, anticipated social approval may also encourage an observer to adopt a model's behavior while anticipated disapproval may have the opposite effect [START_REF] Bandura | Social foundations of thought and action: A social cognitive theory[END_REF].

In the context of working hours, the above discussion suggests that imitation desirability depends on the extent to which (a) the organization rewards the supervisor through tangible and intangible benefits (vicarious reinforcement), (b) the subordinate values working long hours (self-reinforcement), and (c) the supervisor's long working hours are consistent with organizational norms (social approval). We argue that these three aspects can be captured by (a) the supervisor's perceived status, (b) the subordinate's work centrality, and (c) the congruence between organizational norms and the supervisor's long work hours, respectively. A fourth notion, the subordinate's identification with the supervisor [START_REF] Ashforth | I identify with her," "I identify with him": Unpacking the dynamics of personal identification in organizations[END_REF], should also contribute to influence the desirability of imitating the supervisor's long working hours. As we explain below, identification with a supervisor may motivate the subordinate to mimic the supervisor's behaviors because of the personal and relational benefits it may generate (e.g., positive self-perceptions and positive impressions on the supervisor) . Our model is illustrated in Figure 1.

=== Insert Figure 1 about here ==

Supervisor's Perceived Status

Social learning theory states that the observer assesses how desirable the outcomes of the role model's behaviors are by observing the environment's response to these behaviors [START_REF] Bandura | Social learning theory[END_REF][START_REF] Bandura | Social foundations of thought and action: A social cognitive theory[END_REF]. In the context of working hours, the subordinate's perception of the supervisor's status is an important feature that will be used to gauge the organization's response to the supervisor's working hours. Supervisor's perceived status refers to the extent to which the supervisor is perceived to be valued by, and influential in, the organization [START_REF] Eisenberger | Perceived supervisor support: Contributions to perceived organizational support and employee retention[END_REF]. A number of cues may convey information on the supervisor's status during the role-taking stage of the supervisor-subordinate relationship. These cues may be communicated by the supervisor him/herself, or other stakeholders: for instance, the supervisor's track record of promotions and visible achievements such as securing large contracts or succeeding in important projects may be discussed within the team, in broader meetings, or alluded to in informal conversations during the socialization process [START_REF] Van Maanen | Towards a theory of organizational socialization[END_REF]. Other cues such as the supervisor's observable influence over peers, higher-ranked organizational members, important clients, and suppliers may also convey information about the supervisor's status (e.g. [START_REF] Tangirala | In the shadow of the boss's boss: Effects of supervisors' upward exchange relationships on employees[END_REF].

A high status signals that the organization rewards the supervisor by granting him or her various benefits (e.g., recognition, access to resources, autonomy). Even if status may not specifically signal that the supervisor's long working hours are rewarded, it indicates that these hours are acceptable and can be safely imitated. Conversely, a low status may convey the impression that working long hours is either not required or even disapproved by the organization (for example, considered as indicative of low productivity), in which case this signal may be picked up by newcomers as discouraging imitation.

Altogether, this reasoning suggests that when a supervisor is perceived as having a high status in the organization, the subordinate will anticipate that mimicking the supervisor's behaviors -including long hours -will increase the chances to earn a similar status [START_REF] Malhotra | Indirect impact of high performers on the career advancement of their subordinates[END_REF]. On the other hand, a supervisor who is seen as having low status is less likely to be imitated because the subordinate may interpret the supervisor's low status as a form of "punishment." This is consistent with Bandura's suggestion (1977Bandura's suggestion ( , 1986) that successful individuals are more likely to serve as models. This idea has received support in Weiss's (1977) and [START_REF] Adler | Subordinate imitation of supervisor behavior: The role of supervisor power and subordinate self-esteem[END_REF] studies where subordinates' perception of their supervisor success in the organization resulted in greater likelihood of imitating the supervisor's behaviors. A supervisor's perceived status may also convey information about the supervisor's degree of reward power. The more the supervisor is perceived to be influential, the more s/he will be seen as having the discretionary power to reward or punish the subordinate (e.g., deciding on his or her advancement or salary increases; [START_REF] Trempe | Subordinate satisfaction with male and female managers: Role of perceived supervisory influence[END_REF]. Subordinates may believe that they have more chances of obtaining those rewards if they model their supervisor's behaviors, particularly in the early stage of the relationship with the supervisor. Indeed, during the role-taking stage, supervisors gauge subordinates' abilities using visible information [START_REF] Goldberg | Diversity and LMX development[END_REF]. Long work hours may inform the supervisor about the subordinate's contributions.

P2. A supervisor's perceived status will be positively associated with the perceived desirability of imitating the supervisor's long working hours.

Subordinate's Work Centrality

Work centrality can be defined as a value or a core belief an individual holds about the relative importance of work in his or her life [START_REF] Carr | The moderating effect of work-family centrality on work-family conflict, organizational attitudes, and turnover behavior[END_REF]. Values constitute a key aspect of one's self-concept [START_REF] Carr | The moderating effect of work-family centrality on work-family conflict, organizational attitudes, and turnover behavior[END_REF][START_REF] Hirschfeld | Work centrality and work alienation: Distinct aspects of a general commitment to work[END_REF]. That is, core beliefs about desirable behaviors and end states contribute to build one's sense of self [START_REF] Gecas | Value identities, self-motives and social movements[END_REF][START_REF] Hirschfeld | Work centrality and work alienation: Distinct aspects of a general commitment to work[END_REF]. Following the tenets of self-consistency theory (Korman, 1970, p. 32), self-conceptions motivate individuals to endorse and adopt attitudes and behaviors which are consistent with their self-views [START_REF] Hirschfeld | Work centrality and work alienation: Distinct aspects of a general commitment to work[END_REF].

It follows that work centrality, as a key feature of the self, likely exerts a substantial impact on one's attitudes and behaviors towards work, and particularly toward one's quantitative investment as one gets socialized in a new work environment [START_REF] Carr | The moderating effect of work-family centrality on work-family conflict, organizational attitudes, and turnover behavior[END_REF]. Indeed, individuals fulfill multiple roles (e.g., employee, parent, community member) but tend to prioritize and invest more time in those they perceive to be important to the characterization of their self-concept [START_REF] Greenhaus | When work and family collide: Deciding between competing role demands[END_REF][START_REF] Lobel | Allocation of investment in work and family roles: Alternative theories and implications for research[END_REF]Stryker & Serpe, 1994;[START_REF] Thoits | On merging identity theory and stress research[END_REF]. Consequently, individuals for whom work is central are likely to regard long working hours as desirable [START_REF] Ng | Long working hours: A social identity perspective on meta analysis data[END_REF]Sharabi & Harpaz 2007;Snir & Harpaz 2002).

Conversely, those with low work centrality are less likely to favor long working hours. Supporting this view, [START_REF] Ng | Long working hours: A social identity perspective on meta analysis data[END_REF] meta-analysis found a positive correlation between work centrality and work hours. Similarly, [START_REF] Carlson | Work-family conflict in the organization: Do life role values make a difference[END_REF] We therefore argue that the extent to which a subordinate is work centric will affect the perceived desirability of imitating the supervisor's long working hours because, as suggested by social learning theory, the subordinate's work centrality influences the assessment of the supervisor's working hours. A subordinate who is family centric is likely to have a less positive view of long working hours. If the supervisor works long hours, this subordinate will anticipate that imitating the supervisor will conflict with his or her self-views. Consequently, this subordinate will perceive that imitating the supervisor's long hours is not desirable and may work fewer hours to maintain a balance with family needs. Conversely, if the supervisor's working hours are congruent with the subordinate's work centrality, the subordinate may perceive imitating the supervisor's working hours as desirable and imitate the long hours early on.

We recognize that the relationship between work centrality and working-hour desirability may not always be straightforward. For example, [START_REF] Masterson | Care and career: A family identity-based typology of dual-earner couples[END_REF] and [START_REF] Ng | Long working hours: A social identity perspective on meta analysis data[END_REF] argued that family-centric individuals may perceive long working hours as a means to support their family by obtaining more economic resources. However, this pattern may be unusual among employees who have some leeway over the number of hours they work. These employees are more likely to be exempt employees (e.g., overtime is not paid for). Hence, working more than the required time would not directly yield surplus income.

P3. A subordinate's work centrality will be positively associated with the perceived desirability of imitating the supervisor's long working hours.

Congruence between a Supervisor's Long Working Hours and Organizational Norms

Understanding the supervisor's influence requires considering the context in which interactions take place [START_REF] Greenhaus | When family-supportive supervision matters: Relations between multiple sources of support and work-family balance[END_REF]Matthew, Mills, Trout, & English, 2014). Following this logic, we propose that the imitation desirability of the supervisor's long working hours will be influenced by organizational norms regarding working hours. We conceptualize these norms as reflecting the standards that are shared within the organization regarding the appropriate number of working hours [START_REF] Birenbaum | Norms and human behavior[END_REF]. As such, working hours represent a feature of an organization's culture [START_REF] Bailyn | Breaking the mold: Women, men, and time in the new corporate world[END_REF][START_REF] Schriber | Some time dimensions of work: Measurement of an underlying aspect of organization culture[END_REF][START_REF] Thompson | When work-family benefits are not enough: The influence of work-family culture on benefit utilization, organizational attachment, and work-family conflict[END_REF], defined as "a pattern of shared basic assumptions […] that has worked well enough to […] be taught to new members as the correct way to perceive, think, and feel in relation to those problems" (Schein, 2004, p.17). Consequently, expectations regarding working hours are internalized by newcomers during the socialization process [START_REF] Van Maanen | Towards a theory of organizational socialization[END_REF] as a way to reduce anxiety and facilitate acceptance into the group [START_REF] Ashforth | Social identity theory and the organization[END_REF]. Furthermore, awareness of organizational norms is important in the area of working hours because working hours reveal employees' dedication to their tasks [START_REF] Acker | Hierarchies, jobs, bodies: A theory of gendered organizations[END_REF][START_REF] Blair-Loy | Competing devotions: Career and family among executive women[END_REF][START_REF] Drago | Long working hours: Volunteers and conscripts[END_REF]. That is, far from being anecdotal, working hours are visible artifacts of the meaning attributed to one's work life. Thus, if the supervisor's working hours are incongruent with organizational norms, that is, if the supervisor puts more hours into work than expected by the organization, then mimicking the supervisor may countervail organizational norms. This may have negative consequences for the employee and lead to feelings of rejection by coworkers. In support of this view, [START_REF] Park | Relationships between work-home segmentation and psychological detachment from work: the role of communication technology use at home[END_REF] found that employees' behaviors regarding work-home segmentation were significantly related to their perception of segmentation norms within their workplace. Similarly, in their meta-analysis of extreme jobs (i.e., jobs with extreme expectations in terms of long working hours), [START_REF] Gascoigne | Extreme work, gendered work? How extreme jobs and the discourse of 'personal choice' perpetuate gender inequality[END_REF] reported that long working hours often resulted from an identification with organizational values, as also pointed out by [START_REF] Alvesson | Identity regulation as organizational control: Producing the appropriate individual[END_REF].

Furthermore, organizational norms may prevail over individual preferences, particularly during the early stages of socialization (Van Maanen & Schein, 1989). Indeed, adjusting one's behavior to organizational norms bears more heavily than personal preferences in regard to assessing the expected outcomes of a behavior. For example, Sturges (2012) reported that while young professionals tended to value work-life balance [START_REF] Lewis | Into work: Job insecurity and changing psychological contracts[END_REF], they still continued to behave in accordance with the long-hours culture in the workplace. [START_REF] Foucreault | Organizational culture and work-life integration: A barrier to employees' respite[END_REF] found that organizational cultures perceived as favoring work-family integration reduced individuals' ability to enact their segmentation preferences. In the same vein, [START_REF] Eastman | Working for position: Women, men, and managerial working hours[END_REF] found that most individuals based their working hours on coworkers' working hours rather than on their preferences.. In addition, organizational norms may also, in some conditions, overrule the supervisor's organizational status. Bandura argued that a model's behavior is unlikely to be modeled if it is incongruent with the observer's perception of what is appropriate to do (i.e., the social norm), even when it is externally rewarded (e.g., through high organizational status). Such an "instance where unacceptable actions are rewarded is more apt to be viewed by observers as an eccentricity" (Bandura, 1986, p. 285). It is therefore important to account for organizational norms, as they may influence the desirability of imitating the supervisor's working hours independently of the supervisor's status or the subordinate's work centrality.

The above discussion suggests that congruence between organizational norms and the supervisor's working hours will increase the desirability of imitating the supervisor.. This view is consistent with [START_REF] Schein | Organizational culture and leadership[END_REF] idea that influence is stronger when messages are consistent across the organization. It is also consistent with related research indicating that the influence of supervisory support regarding work-family balance on subordinates' own work-family balance is stronger when it is consistent with organizational policies (Greenhaus et al., 2012).

P4. Congruence between organizational norms and a supervisor's long working hours will be positively associated with the perceived desirability of imitating the supervisor's long working hours.

Identification with the Supervisor

Identification with one's supervisor occurs when a subordinate internalizes some characteristics of the leader into his or her own identity (van Knippenberg, van [START_REF] Van Knippenberg | Leadership, self, and identity: A review and research agenda[END_REF]. A subordinate who identifies with the supervisor feels a strong connection with him or her, tends to feel associated with the supervisor's behaviors, and seeks this association. We argue that identification with the supervisor may drive the contagion of working hours during the role-taking stage of the relationship. Employees are likely to establish their working hours rather quickly when they join a new organization. At this stage, identification with the supervisor may develop based on perceived similarity or the supervisor's reputation and values [START_REF] Gibson | Role models in career development: New directions for theory and research[END_REF].

Identification with the role model increases the likelihood that the observer imitates the role model's behaviors [START_REF] Ashforth | I identify with her," "I identify with him": Unpacking the dynamics of personal identification in organizations[END_REF][START_REF] Bussey | Influence of gender constancy and social power on sex-linked modeling[END_REF][START_REF] Kelman | Processes of opinion change[END_REF]. Indeed, identification may foster vicarious learning above and beyond the influence of external rewards for the behavior because of the personal and relational benefits the subordinate can expect from behaving consistently with the supervisor. First, imitating the supervisor's behavior may be selfsatisfying for the subordinate [START_REF] Kelman | Processes of opinion change[END_REF] and foster a positive perception of him/herself. Second, identification with the supervisor may encourage the subordinate to adopt the supervisor's behavior as a means to be positively perceived by him or her (Gu, Tang, & Jiang, 2015;[START_REF] Kelman | Processes of opinion change[END_REF]. This process may be particularly salient in the role-taking stage, where the subordinate may use imitation as an ingratiation strategy to manage the supervisor's impressions [START_REF] Wayne | Developing leader-member exchanges: The influence of gender and ingratiation[END_REF].

The role of identification as a driver of influence processes has been studied in related areas of research. For instance, it has been argued that identification with a mentor exerts a powerful influence [START_REF] Ashforth | I identify with her," "I identify with him": Unpacking the dynamics of personal identification in organizations[END_REF][START_REF] Kram | Mentoring at work: Developmental relationships in organizational life[END_REF] and that individuals tend to identify with their role models [START_REF] Ashforth | I identify with her," "I identify with him": Unpacking the dynamics of personal identification in organizations[END_REF][START_REF] Gibson | Developing the professional self-concept: Role model construals in early, middle, and late career stages[END_REF][START_REF] Gibson | Role models in career development: New directions for theory and research[END_REF]. Furthermore, the role of identification with the supervisor has been recognized as a mechanism of successful influence [START_REF] Ashforth | I identify with her," "I identify with him": Unpacking the dynamics of personal identification in organizations[END_REF][START_REF] Chun | Leadership across hierarchical levels: Multiple levels of management and multiple levels of analysis[END_REF]. Of relevance to our arguments, Zhang and Seo (2016) hypothesized that working hours' contagion within supervisor-subordinate dyads would be stronger when the subordinate's identification with the supervisor is higher. While they actually found the reverse (i.e., the relationship between supervisors' and subordinates' work hours was stronger among low-identifiers), their sample was composed of mature supervisorsubordinate dyads. In such dyads, as we discuss later, subordinates' need to demonstrate their value may be less pressing. Therefore, subordinates in these dyads may think the supervisor will be tolerant of deviations from long work hours' habits, suggesting that identification with the supervisor may reduce imitation desirability. In contrast, in the early development of the relationship, identification with the supervisor should increase the desirability of imitating one's supervisor's work hours because supervisors are likely to interpret such imitation as an indication of successful work adjustment. Thus, subordinates who identify with the supervisor may imitate the supervisor's long hours in order to generate favorable impressions. Altogether, the above arguments suggest that identification serves as a powerful mechanism of vicarious learning in the role-taking stage of the supervisor-subordinate relationship.

P5. A subordinate's identification with the supervisor will be positively associated with the perceived desirability of imitating the supervisor's long working hours.

We have so far argued that four constructs, supervisor's perceived status, subordinate's work centrality, congruence between organizational norms and supervisor's long working hours, and subordinate's identification with the supervisor, act as antecedents to the desirability of imitating the supervisor's long working hours during the role-taking stage of the supervisor-subordinate relationship. However, our discussion has noted that in some cases, these antecedents may exert competing influences on imitation desirability. For example, a supervisor who works long hours may be successful, which should positively influence imitation desirability; yet, at the same time, a weak work centrality from the subordinate may reduce imitation desirability. To probe more deeply into the motivational process underlying vicarious learning, we suggest that individuals' self-motives may alter the influence of the above antecedents of imitation desirability. Selfmotives act as lenses through which subordinates assess the value of the antecedents we identified, that is, the value of the expected outcomes associated with modeling the supervisor's working hours. Indeed, vicarious learning is not only conditional on the observer's expected outcomes but also on the value s/he places on the outcomes [START_REF] Manz | Vicarious learning: The influence of modeling on organizational behavior[END_REF]Weiss, 1977).

If the expected outcomes are not valued, they are unlikely to encourage imitation. Therefore, the predictive power of the four antecedents should depend on how the subordinate values them. We argue that outcome desirability can be influenced by the following self-motives: selfenhancement, self-verification, belongingness, and self-improvement. We now proceed to detail how these self-motives operate in our model.

The Moderating Role of Self-Motives

Various motives guide human behavior (e.g., [START_REF] Baumeister | The self in social psychology[END_REF][START_REF] Cooper | Identification in organizations: The role of self-concept orientations and identification motives[END_REF][START_REF] Sedikides | The multiply motivated self[END_REF][START_REF] Vignoles | Beyond self-esteem: influence of multiple motives on identity construction[END_REF]. No consensus has emerged on a list of the most prominent motives, the relations between them, and their relative strength across settings [START_REF] Vignoles | Beyond self-esteem: influence of multiple motives on identity construction[END_REF]. Based on a review of the literature on primary self-motives [START_REF] Brewer | The social self: On being the same and different at the same time[END_REF][START_REF] Vignoles | Beyond self-esteem: influence of multiple motives on identity construction[END_REF], we identified five motives that might influence the perceived desirability of imitating one's supervisor's working hours: the need for self-verification, self-enhancement, self-improvement, personalized belongingness and depersonalized belongingness.

Studies demonstrated that individuals vary in the extent to which they are driven by these motives [START_REF] Gregg | Quantifying self motives: Functional links between dispositional desires[END_REF][START_REF] Hepper | Individual differences in self enhancement and self protection strategies: An integrative analysis[END_REF]. For instance, the self-enhancement need is higher among narcissists [START_REF] Paulhus | Interpersonal and intrapsychic adaptiveness of trait self-enhancement: A mixed blessing[END_REF]. Contextual factors also affect the activation and intensity of the different motives [START_REF] Gregg | Quantifying self motives: Functional links between dispositional desires[END_REF][START_REF] Sedikides | Portraits of the self[END_REF][START_REF] Sedikides | The multiply motivated self[END_REF]. For instance, the need for self-verification is stronger in established relationships than in emerging ones [START_REF] Swann | Identity negotiation at work[END_REF]. Although these motives are not mutually exclusive [START_REF] Cooper | Identification in organizations: The role of self-concept orientations and identification motives[END_REF], the literature suggests that one motive is generally more salient than the others for a given person in a given situation.

4.1 Need for Self-Enhancement. The need for self-enhancement refers to individuals' desire to present themselves in a positive light and to receive feedback that improves their self-views [START_REF] Baumeister | The self in social psychology[END_REF]. Individuals with a strong need for self-enhancement strive to get a positive feedback on their behaviors, traits, and attributes [START_REF] Pfeffer | Building organization theory from first principles: The selfenhancement motive and understanding power and influence[END_REF]. In the workplace, the self-enhancement motive may prompt individuals to engage in behaviors that are well-regarded by others or rewarded because these behaviors would be perceived as enhancing one's and others' view of the self. For example, an individual may work long hours because s/he observes that in the organization putting in long hours is well regarded and give access to tangible (e.g., salary increase, advancement) or intangible (e.g., positive comments) rewards.

We previously argued that a supervisor's perceived status may influence the desirability of imitating the supervisor's working hours because it signals that imitating the supervisor may bring high status and benefits to the subordinate.. Such visible incentives may be appealing for those with a high need for self-enhancement because they seek social approval. Conversely, those with a low need for self-enhancement may not be interested by such attributes if they do not value them. This rationale is consistent with [START_REF] Pfeffer | Building organization theory from first principles: The selfenhancement motive and understanding power and influence[END_REF] proposition that the self-enhancement motive is a compelling human need that accounts for compliance to authority in organizational contexts, particularly at the beginning of one's career path and when the source of authority is perceived as successful.

P6. A subordinate's need for self-enhancement will moderate the relationship between

supervisor's perceived status and imitation desirability such that supervisor's perceived status will be more (less) positively associated with imitation desirability when the subordinate's need for self-enhancement is higher (lower).

Need for Self-Verification.

The need for self-verification refers to individuals' desire to maintain a stable view of themselves across time and situations [START_REF] Swann | Agreeable fancy or disagreeable truth? Reconciling self-enhancement and self-verification[END_REF]. This yearning has a strong influence on people's behaviors because it prompts them to behave consistently with their self-views (Shamir, House, & Arthur, 1993). By doing so, individuals self-verify (Swann, 1987(Swann, , 1990) ) and maintain a sense of cognitive coherence [START_REF] Sedikides | Portraits of the self[END_REF]. For example, someone who sees him/herself as fully dedicated to work will likely work long hours because doing so enhances the perception that s/he is dedicated to work. Thus, when assessing the desirability of modeling the supervisor's working hours, subordinates with a high need for self-verification will seek to maintain concordance with their self-views, which, in the context of work hours, implies looking at their work centrality. A subordinate who perceives him/herself as work centric will consider working long hours as desirable because such behavior is in line with his or her self-conception. Conversely, a subordinate with a low need for selfverification will likely attribute more importance to social expectations than to his or her selfview.

P7. A subordinate's need for self-verification will moderate the relationship between

subordinate's work centrality and imitation desirability, such that subordinate's work centrality will be more (less) positively associated with imitation desirability when the subordinate's need for self-verification is higher (lower).

Need for Belongingness.

The need for belongingness refers to the need to be affiliated with and accepted by others. As a primary human motive, this need can be defined as a "fundamental human motivation (...) to form and maintain at least a minimum quantity of lasting, positive, and significant interpersonal relationships" (Baumeister & Leary 1995, p. 497). This need can be split into the need for personalized belongingness and the need for depersonalized belongingness. The distinction between these two needs is important because they lead to a differential impact of identification to individuals vs. groups [START_REF] Cooper | Identification in organizations: The role of self-concept orientations and identification motives[END_REF]. Specifically, the need for personalized belongingness should increase the salience of identification with persons (e.g., the supervisor), while the need for depersonalized belongingness should increase the salience of identification with groups (e.g., the organization, a business unit). In regard to working hours, depending which need dominates, the influence of the supervisor vs. the organization will be more salient.

The need for depersonalized belongingness [START_REF] Mael | Identification in work, war, sports, and religion: Contrasting the benefits and risks[END_REF] refers to the need to feel included in a group. We have argued that the socialization process fosters identification with the organization and the internalization of its values and norms, prompting the subordinate to adopt behaviors congruent with workplace norms. That is, individuals who identify with the organization are likely to adopt its norms [START_REF] Barreto | You can't always do what you want: Social identity and self-presentational determinants of the choice to work for a low-status group[END_REF][START_REF] Mackie | Social identification effects in group polarization[END_REF].

Conversely, those who do not comply with workplace norms run the risk of social exclusion [START_REF] Abrams | Pro-norm and anti-norm deviance within and between groups[END_REF][START_REF] Marques | Being better by being right: Subjective group dynamics and derogation of in-group deviants when generic norms are undermined[END_REF]. The behaviors of those for whom inclusion within the group is critical may be particularly influenced by the organization's norms. Altogether, the above reasoning suggests that when the subordinate'sneed for depersonalized belongingness is high, the influence of organizational norms on the imitation desirability of the supervisor's working hours is likely heightened. Indeed, because the subordinate strives to maintain social inclusion, the congruence between the supervisor's working hours and organizational norms regarding working hours will strongly influence his or her willingness to imitate the supervisor. Conversely, subordinates who are less concerned by their inclusion in the workplace should pay less attention to organizational norms.

P8. A subordinate's need for depersonalized belongingness will moderate the relationship between congruence of supervisor's working hours with organizational norms and

imitation desirability such that congruence will be more (less) positively associated with imitation desirability when the subordinate's need for depersonalized belongingness is higher (lower).

The need for personalized belongingness refers to the need to build and maintain close personal relationships with other individuals and to feel validated as a person [START_REF] Rogers | Respect in organizations: Feeling valued as "We" and "Me[END_REF]. Individuals with a high need for personalized belongingness are sensitive to signals that indicate they are liked vs. rejected by significant others [START_REF] Baumeister | The need to belong: desire for interpersonal attachments as a fundamental human motivation[END_REF].

For subordinates high on this need, identification with the supervisor should play an important role in shaping the imitation desirability of the supervisor's working hours. Indeed, these subordinates will be eager to maintain a close relationship with the supervisor. They will find it desirable to model their supervisor's behaviors because they may see imitation as the safest way to maintain a bond with the supervisor.

P9. A subordinate's need for personalized belongingness will moderate the relationship between identification with the supervisor and imitation desirability such that identification with the supervisor will be more (less) positively associated with imitation desirability when the subordinate's need for personalized belongingness is higher (lower).

4.4 Need for Self-Improvement. The need for self-improvement refers to the desire to improve aspects of the self [START_REF] Sedikides | A multiplicity of motives: The case of self-improvement[END_REF] to become closer to the desired self [START_REF] Banaji | The self in social contexts[END_REF]. This includes developing skills, adopting new attitudes, or improving well-being [START_REF] Sedikides | A multiplicity of motives: The case of self-improvement[END_REF][START_REF] Sedikides | Self-evaluation: To thine own self be good, to thine own self be sure, to thine own self be true, and to thine own self be better[END_REF]. To obtain information to reach their goals, individuals who wish to self-improve tend to make upward comparisons [START_REF] Taylor | Self-evaluation processes[END_REF].

Therefore, the supervisor is likely to constitute a relevant target of comparison, even more so when the subordinate identifies with him or her [START_REF] Gibson | Developing the professional self-concept: Role model construals in early, middle, and late career stages[END_REF][START_REF] Lockwood | Superstars and me: Predicting the impact of role models on the self[END_REF].

Indeed, asubordinate high in need for self-improvement, will likely compare his/her behaviors to those of the supervisor in order to identify specific supervisory behaviors that may help to selfimprove.

Long working hours may be perceived as relevant behaviors to mimic for self-improvement because they may seem to result in various desirable outcomes (e.g., expertise, status, selfesteem). For instance, subordinates who attribute the supervisor's professional expertise to the long hours s/he devotes to work may mimic the supervisor in the hope of improving their own expertise.

P10. A subordinate's need for self-improvement will moderate the relationship between identification with the supervisor and imitation desirability such that identification with the supervisor will be more (less) positively associated with imitation desirability when the subordinate's need for self-improvement is higher (lower).

Imitation Desirability in the Role-Routinization Stage

Our model has focused so far on highlighting the mechanisms involved in working hours' contagion during socialization (role-taking stage). However, the weight of the mechanisms described in our model may change as the relationship with the supervisor becomes more established. That is, we expect that a critical aspect that may affect our model over time is the stage of the relationship between the subordinate and the supervisor, as conceptualized in the LMX literature. We argue that, as the relationship becomes routinized, the weight of some predictors of the contagion process changes, with the stage of LMX development being a moderator in this process. Supporting this view, Graen & Ulh-Bien (1991) proposed that the supervisor's influence differs depending on LMX stage. Past research has also emphasized the role of LMX stage on various constructs such as trust in supervisor, performance ratings, objective performance, and effectiveness of the supervisor's behavior (e.g., [START_REF] Duarte | Effects of dyadic quality and duration on performance appraisal[END_REF][START_REF] Frazier | The path(s) to employee trust in direct supervisor in nascent and established relationships: A fuzzy set analysis[END_REF][START_REF] Vecchio | Leader-member exchange, objective performance, employment duration, and supervisor ratings: Testing for moderation and mediation[END_REF].

Among plausible changes, we expect that LMX stage will affect the influence of work centrality, identification with supervisor, and supervisor's perceived status on imitation desirability. Scholars have suggested that the need to self-verify may be undermined during the emergence stage (i.e., role-taking) of a dyadic relationship, particularly if it is asymmetric [START_REF] Swann | Identity negotiation at work[END_REF]. However, the need to self-verify may resurge as the relationship becomes routinized because the tendency to maintain consistency between one's behavior and one's selfviews can be more safely expressed [START_REF] Liden | A longitudinal study on the early development of leader-member exchanges[END_REF][START_REF] Park | Only time will tell: The changing relationships between LMX, job performance, and justice[END_REF]. Applying this logic to our model, we posit that the influence of work centrality will increase as the LMX relationship evolves toward routinization because the need to self-verify may be expressed more intensely at this stage. A subordinate low in work centrality may for example first imitate the supervisor's long working hours and then gradually reduce his or her working hours so as to restore consistency with the self.

In contrast, the need for personalized belongingness may be particularly salient during the role-taking stage of LMX as the subordinate strives to establish positive relationships at work [START_REF] Baumeister | The need to belong: desire for interpersonal attachments as a fundamental human motivation[END_REF]. Once a positive relationship with the supervisor is established, the need to form close interpersonal bonds should be met and therefore less salient [START_REF] Baumeister | The need to belong: desire for interpersonal attachments as a fundamental human motivation[END_REF]. This suggests that identification with the supervisor will be particularly influential in the role-taking stage, and will then decrease as the routinization stage is reached. Furthermore, at later stages of the relationship, identification is likely accompanied by a relationship of high quality (Gu, Tang, & Jiang, 2015). In such situation, the subordinate's contribution is recognized (Dockery, Steiner, & Dirk, 1990). Consequently, the subordinate may feel freer to work shorter hours [START_REF] Zhang | Held captive in the office: an investigation into long working hours among Korean employees[END_REF]. Identification would then have less impact on imitation desirability.

Lastly, we have previously argued that supervisor's perceived status would positively influence the desirability of mimicking supervisory long hours because of the association of status and reward power in the subordinate's eyes. However, as the relationship stabilizes, the supervisor will hold a well-informed view of the subordinate's performance [START_REF] Goldberg | Diversity and LMX development[END_REF]. The subordinate may be conscious that the weight of working hours on the supervisor's decisions regarding reward allocation will decrease accordingly. Therefore, the influence of the supervisor's perceived status on working hours' desirability should diminish.

P11. The stage of LMX development will moderate the influence of the factors of perceived desirability of imitating the supervisor's long working hours such that, in the routinization (vs. role-taking) stage of LMX: (a) the relationship between subordinate's work centrality and imitation desirability will be stronger (vs. weaker); (b) the relationship between subordinate's identification and imitation desirability will be weaker (vs. stronger); c) the relationship between supervisor's perceived status and imitation desirability will be weaker (vs. stronger).

Other contextual changes may occur over time, triggering changes in the desirability of imitating the supervisor's long working hours. For instance, the subordinate's work centrality may change following a life event such as the birth of a baby or the development of a disease (Sharabi & Harpaz, 2007). Similarly, organizational norms may evolve when the executive board establishes new cultural norms [START_REF] Schein | Organizational culture and leadership[END_REF]. Our model suggests that such changes will modify the relative weight of the factors of imitation desirability.

Discussion

Theoretical and Practical Contributions

This paper draws upon social learning theory [START_REF] Bandura | Social learning theory[END_REF][START_REF] Bandura | Social foundations of thought and action: A social cognitive theory[END_REF][START_REF] Manz | Vicarious learning: The influence of modeling on organizational behavior[END_REF] to propose a model that analyzes the mechanisms underlying the contagion of long working hours from leaders to subordinates at different stages of their relationship. As such, it makes several important contributions. First, by linking vicarious learning to self-motives, we advance knowledge about social learning. In vicarious learning, motivation is viewed through the lens of the expected outcomes associated with the model's behavior (i.e., rewards and/or punishments; [START_REF] Bandura | Social foundations of thought and action: A social cognitive theory[END_REF]. However, little attention has been devoted to the process by which observers gauge the various and sometimes conflicting outcomes of the model's behavior. Although [START_REF] Bandura | Social learning theory[END_REF] acknowledged the contradictory nature of some outcomes, he did not explore how the observer processes this information. We suggest that an individual's self-motives help elucidate how the outcomes of the model's behavior are cognitively processed and, as such, influence vicarious learning. This proposition also has implications for leadership theories that describe role modeling as a mechanism promoting leader effectiveness (e.g. authentic, ethical, charismatic, or transformational leadership). In this regard, the nascent stream of research that examines the role of subordinates' self-concept (e.g., [START_REF] Howell | The role of followers in the charismatic leadership process: Relationships and their consequences[END_REF][START_REF] Jackson | When opposites do (and do not) attract: Interplay of leader and follower self-identities and its consequences for leader-member exchange[END_REF] and followership (e.g., [START_REF] Avolio | Leadership: Current theories, research, and future directions[END_REF][START_REF] Epitropaki | Leadership and followership identity processes: A multilevel review[END_REF] in leadership effectiveness is promising.

Second, our model contributes to deepening the understanding of the mechanisms related to behavioral contagion. Several scholars have used social learning as a framework to account for behavioral contagion in the workplace (e.g., [START_REF] Bommer | Does one good turn deserve another? coworker influences on employee citizenship[END_REF][START_REF] Mayer | Who displays ethical leadership, and why does it matter? An examination of antecedents and consequences of ethical leadership[END_REF][START_REF] Robinson | Monkey see, monkey do: The influence of work groups on the antisocial behavior of employees[END_REF]. However, to our knowledge, no specific model has been proposed that analyzes the process of such contagion over time. Our model is a preliminary attempt at doing so and specifically depicts the why (e.g., key antecedents) and when (e.g., self-motives as boundary conditions and, therefore, who is more likely to imitate) of vicarious learning in the context of long working hours.

Third, the present model contributes to the FSSB literature. In the last decade, there has been a growing interest in the role of supervisors in facilitating employees' work-life balance [START_REF] Li | The influence of leadership behavior on employee work-family outcomes: A review and research agenda[END_REF]Straub, 2012). We contribute to this line of research because long working hours have a major impact on work-life balance (Haar, Sune, Russo, & Ollier-Malaterre, in press;[START_REF] Thompson | When work-family benefits are not enough: The influence of work-family culture on benefit utilization, organizational attachment, and work-family conflict[END_REF]. Our theoretical model heeds the call of [START_REF] Hammer | Clarifying the construct of family-supportive supervisory behaviors (FSSB): A multilevel perspective[END_REF] to clarify the mechanisms of FSSBs (or lack thereof). Furthermore, the FSSB literature refers to role modeling as "the extent to which supervisors provide examples of strategies and behaviors that employees believe will lead to desirable work-life outcomes" (Hammer et al., 2009, p. 4). As such, this literature views role modeling as an active strategy that a supervisor consciously implements (e.g., through discussing benefits of their behaviors with subordinates) to influence subordinates' work-life balance. Our model suggests role modeling is also influenced by the subordinates' perception of the benefits attached to adopting their supervisor's behaviors. This echoes [START_REF] Gibson | Role models in career development: New directions for theory and research[END_REF] suggestion that while leaders are urged to act as role models, the effectiveness of role modeling is forged by the observers' representations. Both views need to be investigated to fully comprehend how and when leaders can serve as relevant role models.

Finally, our paper contributes to the literature heavy work investment (Snir & Harpaz, 2012) by suggesting that overinvestment at work, which is often thought to be caused by individual characteristics (e.g., demographics, personality), may also be determined by the social environment, particularly the supervisor's own overinvestment in work activities. Supporting this argument, [START_REF] Mazzetti | Are workaholics born or made? Relations of workaholism with person characteristics and overwork climate[END_REF] found that workaholism was predicted by both personal characteristics and an overwork climate in the organization. Although workaholism involves more than working long hours [START_REF] Clark | All work and no play? A meta-analytic examination of the correlates and outcomes of workaholism[END_REF], our approach supports the idea that the antecedents of workaholism might include the supervisor's own workaholism [START_REF] Ng | Dimensions, antecedents, and consequences of workaholism: A conceptual integration and extension[END_REF].

From a practical perspective, our model points to how cultures promoting long hours can spread in organizations. Substantial evidence indicates that persistent long hours negatively affect employee health and well-being (e.g., [START_REF] Goh | The relationship between workplace stressors and mortality and health costs in the United States[END_REF]Sparks, Cooper, Fried, & Shirom, 1997;[START_REF] Virtanen | Long working hours and coronary heart disease: A systematic review and metaanalysis[END_REF]. Therefore, understanding how supervisors' long hours influence their subordinates' own working hours offers opportunities for interventions aimed at fostering more supportive and sustainable work cultures. With this aim in mind, executives and supervisors may want to monitor their own work hours, as these can be contagious. Managers who want to act as role models should adopt leadership styles such as transformational leadership that foster identification [START_REF] Walumbwa | Understanding transformational leadershipemployee performance links: The role of relational identification and self efficacy[END_REF].

Organizations can also develop a healthier culture regarding working hours by promoting norms that keep supervisors' working hours within reasonable limits and ensuring career success for supervisors who work fewer hours. In addition, the expectations regarding work hours should be disclosed during the selection process to prevent incongruence between newcomers' and the organization's expectations. Employees' expectations regarding working hours, as we argued, are grounded in their work centrality. If these expectations cannot be met, employees are likely to leave due to misfit between their values and organizational norms, as per the tenets of the attraction-selection-attrition model [START_REF] Schneider | The people make the place[END_REF].

Boundary Conditions and Future Research

For the sake of parsimony, our theorizing has exclusively focused on the core process of working hours' contagion. However, researchers wishing to develop this model may notice that it is bounded by several factors. First, our theorizing unpacks social contagion processes in traditional employment situations where subordinates have one main role model, (i.e., their supervisor). However, future research could examine how social contagion unfolds when individuals expand the pool of possible role models at later career stages [START_REF] Gibson | Developing the professional self-concept: Role model construals in early, middle, and late career stages[END_REF], report to several supervisors simultaneously, or have worked with other supervisors in the past. It is reasonable to expect that exposure to multiple role models who exhibit different work patterns may reduce every single model's influence on subordinate behaviors and render the subordinate's work centrality a more critical factor of imitation desirability.

Second, examining the effects of gender would be an interesting avenue. Gender may moderate the impact of work centrality on imitation desirability. Research indicates that women are still expected to assume a greater share of responsibilities for household care, suggesting that long working hours may be more desirable, socially acceptable, and feasible, for work-centric men than for work-centric women [START_REF] Greenhaus | Relations of work identity, family identity, situational demands, and sex with employee work hours[END_REF]. In addition, vicarious learning is assumed to be bounded by similarity between the observer and the model such that vicarious rewards and punishments "exert little impact when the modeled conduct is so markedly inappropriate to the sex, status, or social role of observers" (1986, p. 285). Therefore, gender dissimilarity may lessen identification with the supervisor as there is less interpersonal attraction [START_REF] Kark | Does valuing androgyny and femininity lead to a female advantage? The relationship between gender-role, transformational leadership and identification[END_REF] in less homophilous dyads [START_REF] Mcpherson | Homophily in voluntary organizations: Status distance and the composition of face-to-face groups[END_REF].

Third, future research should investigate the role of contextual factors such as job security and national culture. Imitating the supervisor's long work hours when job security in one's country, industry or occupation is low, may act as a strategy to keep one's job. In addition, the cultural context likely influences several constructs in our model, such as the degree of work centrality. The long work hours norm in North America reveals the dominance of a protestant work ethic [START_REF] Dumas | The professional, the personal, and the ideal worker: Pressures and objectives shaping the boundary between life domains[END_REF][START_REF] Williams | Cultural schemas, social class, and the flexibility stigma[END_REF], suggesting that self-worth derives from one's dedication to work [START_REF] Morrow | Concept redundancy in organizational research: The case of work commitment[END_REF]. In cultures dominated by a protestant work ethic, subordinates, supervisors, and team members may share the belief that working long hours is desirable [START_REF] Hirschfeld | Work centrality and work alienation: Distinct aspects of a general commitment to work[END_REF], leading to more alignment among subordinates' preferences, supervisors' behavior, and organizational norms. National culture may also influence subordinates' self-motives. Culture influences the construction of the self [START_REF] Markus | Culture and the self: Implications for cognition, emotion, and motivation[END_REF][START_REF] Triandis | The self and social behavior in differing cultural contexts[END_REF], while the self-concept in turn impacts the salience of selfrelated motives [START_REF] Cooper | Identification in organizations: The role of self-concept orientations and identification motives[END_REF][START_REF] Cross | The what, how, why, and where of selfconstrual[END_REF]. The selfconcept's orientation, that is, the tendency to define the self on the basis of individual attributes, relationships or group belonging [START_REF] Cooper | Identification in organizations: The role of self-concept orientations and identification motives[END_REF], is thought to be shaped by one's cultural context [START_REF] Markus | Culture and the self: Implications for cognition, emotion, and motivation[END_REF][START_REF] Triandis | The self and social behavior in differing cultural contexts[END_REF]. Individuals raised in Western cultures tend to have an individual self-concept orientation, which is presumably associated with greater needs for self-enhancement and self-verification. In contrast, people raised in Asian cultures tend to hold relational or collective self-concept orientations [START_REF] Cross | The what, how, why, and where of selfconstrual[END_REF]Markus & Kitamaya, 1991), which would make the needs for personalized and depersonalized belongingness more salient [START_REF] Cooper | Identification in organizations: The role of self-concept orientations and identification motives[END_REF][START_REF] Cross | The what, how, why, and where of selfconstrual[END_REF].

Fourth, for the sake of clarity, we have theorized the antecedents of imitation desirability as being independent. However, they may be interrelated. For example, the supervisor's perceived status may be related to the supervisor's attractiveness, which may impinge upon the subordinate's identification with the supervisor. The interrelationships among the antecedents of imitation desirability are worth exploring in future research. Finally, our model points towards the need to further understand the main and interactional effects of dispositional and situational determinants of self-motives. Although self-motives are assumed to be rather stable over one's life, their activation and strength may vary across situations [START_REF] Sedikides | Portraits of the self[END_REF].

However, no framework has been proposed that can account for this variability [START_REF] Anseel | How are we doing after 30 years? A meta-analytic review of the antecedents and outcomes of feedback-seeking behavior[END_REF]. Identifying those factors that activate particular self-motives would help determine the relative weight of the antecedents of imitation desirability in various contexts and facilitate a better grasp of the conditions where contagion of working hours between supervisors and subordinates occurs.

Conclusion

Drawing upon the literature on social learning and self-motives, this paper develops an integrated model that analyzes the mechanisms explaining the contagion of long working hours from supervisors to employees. Our model contributes to the understanding of why the longhours norm persists in organizations and how it can be managed in the best interests of employees. While this model acknowledges the role organizations play in how a supervisor's working hours influence his/her subordinates' working hours, it also suggests that supervisors are powerful agents of change. Shamir, B., House, R. J., & Arthur, M. B. (1993) (1990). To be adored or to be known? The interplay of self-enhancement and selfverification. In R. M. Sorrentino & E. T. Higgins (Eds.), Handbook of motivation and cognition: Foundations of social behavior, Vol. 2,. New York, NY: Guilford Press.

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We focus in this article on the behavioral component of working hours rather than on the mental states accompanying long working hours such as compulsive work and obsession toward work(Clark et al.,

2016). Consequently, our paper contributes to the workaholism literature only to the extent that long hours are but one attribute of workaholism[START_REF] Clark | All work and no play? A meta-analytic examination of the correlates and outcomes of workaholism[END_REF].

This research has been supported by a fellowship from the FQRSC (Fonds de Recherche du Québec, Société et Culture) (fellowship number 205897) to Marie-Colombe Afota.

Declaration of interest: None.