How conflict affects the relationship between team tenure diversity and team performance

Transcription

1 How conflict affects the relationship between team tenure diversity and team performance The mediating role of conflict S.I. Glaap s Fagotlaan 54, 3438 CH Nieuwegein Supervisor: Hans van Dijk Project period: January 2010 February 2011 Project theme: Diversity 1

2 Abstract This study examines whether differences in team tenure result in enhanced or detrimental team performance, mediated by four types of conflict. The study used a cross-sectional design, maintaining 30 R&D- and 6 fire fighting teams. The results indicate that the relationship between team tenure diversity and team performance is not mediated by any type of conflict. Unexpectedly, team tenure diversity did not have a relationship with any type of conflict. In line with previous research, results did revealed a negative relationship for any kind of conflict on team performance. With regard to control variables, no additional effects were found when age diversity was added in the model. Control variable group longevity was highly correlated with team tenure diversity. Additional tests indicate that group longevity is positively related to relationship conflict and positively related to team performance, opposite to tenure. Practical implications and directions for future research are discussed. 2

3 Introduction The empirical body of research to the effects of work group diversity and performance is growing. An explanation for this growing attention to work group diversity is that with the increased use of work groups in organizations, it has become even more important how diversity in group member characteristics such as age, gender, race (i.e. demographic), tenure, and functional background (i.e. job-related) affect teams and why (Harrison & Klein, 2007). Research has shown that the consequences of diversity on team performance are mixed. On the one hand, diversity has been related to positive outcomes like higher quality decisions, greater creativity, and more innovation (i.e. Milikken & Martins, 1996; Williams & O Reilly, 1998). On the other hand, diversity has also been related to more negative outcomes, such as increased tensions and conflicts (Garcia-Prieto, Bellard, & Schneider, 2003). Conclusions of recent and previously executed reviews and meta-analyses show that the effects of team tenure diversity on team performance are still ambiguous and inconclusive (Williams & O Reilly, 1998; Van Dijk, Van Engen, & Van Knippenberg, 2009). Therefore, the relevance of gaining new insights is present. Since the relationship, next to other diversity categories, between team tenure diversity and team performance is still unclear (Williams & O Reilly, 1998; Van Dijk, Van Engen, & Van Knippenberg, 2009), van Knippenberg and Schippers (2007) stated that it is necessary to increase attention to this field. A way to improve this, is putting a premium on identifying moderator and mediator variables that can explain these different outcomes (Van Knippenberg & Schippers, 2007). One of these mediator variables that could affect the relationship between team tenure diversity and performance is conflict (Pelled, 1996). Due to increased team tenure diversity in work teams, the likelihood for conflicts to occur grows (Jehn, Northcraft & Neale, 1999). Increasing diversity generally result in a greater likelihood that individuals interact with dissimilar others who have dissimilar attributes, viewpoints, and backgrounds (Pelled, Eisenhardt & Xin, 1999). This makes working effectively in a diverse team challenging, because of the differences between the members of a particular workgroup, the occurrence of conflicts is presents. Additionally, diversity with respect to team tenure diversity is apt to have strong relationships with conflicts (Pelled, 1996; Pelled et al., 1999). Therefore, this study tries to gain more insights in the mediating role of conflicts in the relationship between team tenure diversity and team performance. This results in the following research 3

4 question: To what extent does conflict mediate the relationship between team tenure diversity and team performance? How team tenure diversity relates to team performance is of great interest to study (Van Dijk, van Engen & van Knippenberg, 2009). Also, previous research reveals inconsistencies in the relationship between team tenure diversity and team performance (i.e. Van Dijk & van Engen, 2010), and the need to identify mediator variables to explain these inconsistencies is of great interest (Van Knippenberg & Schippers, 2007). In practice, teams can no longer be seen as stable entities. Since people change jobs more frequently, it is important to investigate what happens to team outcomes when team compositions change (Hirst, 2009). In the following, the current state of science regarding the team tenure diversity-performance relationship will be discussed and hypotheses regarding the mediating impact of conflict will be derived. Theoretical framework and hypotheses Team tenure diversity and team performance Diversity refers to differences between individuals (Williams & O Reilly, 1998). Diversity research can be categorized in three streams; research to demographic diversity such as age, gender, or race (i.e., Pelled, 1996), research to deep-level diversity characteristics such as attitudes, values, and beliefs (i.e., Harrison, Price & Bell, 2007), and research to job-related types of diversity such as functional background or tenure (i.e., Pelled et al., 1999). This study concentrates on a job-related type of diversity, namely team tenure diversity. Team tenure diversity refers to how long one has worked in a particular team and how this differs between team members (Pelled et al., 1999). An important question in diversity research is how these differences between team members affect group processes and performance, as well as team member s attitudes, and well-being. To address this subject, diversity research has largely been driven by two research traditions: the social categorization perspective and the information/decision-making perspective (Williams & O Reilly, 1998). From the social categorization perspective, it is argued that similarities and differences between team members form the basis for categorizing self and others into groups, distinguishing between members of the similar in-group and the dissimilar out-group. Since people tend to like in-group members more than out-group members, they are more enthusiastic to work cooperatively with 4

5 similar in-group members (Tajfel & Turner, 1986). Results of such categorization processes can be that teams work more easily when teams are homogenous than when teams are more diverse (Van Knippenberg & Schippers, 2007). According to this perspective, team members, who categorize themselves and others into groups based on the attribution of tenure, tend to favor working with others with similar tenure in their team. Team members with equal team tenure, are perceived as similar and therefore put in their in-group. Thus, teams with higher levels of team tenure diversity, where members are more heterogeneous on this attribute, should perform worse in comparison to teams with lower levels of team tenure diversity (i.e. Van Knippenberg, De Dreu & Homan, 2004). In contrast to the social categorization perspective, the information decision-making perspective puts more emphasis on the positive effects of team diversity. This perspective states that diverse teams are likely to hold a broader range of task-relevant knowledge, skills, and abilities. Team members are more likely to have different opinions and perspectives (Van Knippenberg & Schippers, 2007). Also, more diverse teams search for new information more broadly (Jackson & Joshi, 2011). As a result, teams have a larger pool of resources that can be helpful in handling non-routine problems (Van Knippenberg & Schippers, 2007). Following this perspective, teams with higher levels of team tenure diversity should perform better in comparison to teams with lower levels of team tenure diversity, since these diverse teams are more likely to hold a broader range of task-relevant knowledge, skills, and abilities. Empirical findings to the relationship between team tenure diversity and performance are inconclusive (Van Dijk et al, 2009). In a study executed by Choi and Thompson (2005), it is concluded that membership changes, which in turn increases team tenure diversity, improves innovation and creativity. Tihanyi, Ellstrand, Daily and Dalton (2000) conclude team tenure heterogeneity is related to increased international diversification by organizations. Others, on the other hand, such as Akgun and Lynn (2002) state that changes in personnel, increasing team tenure diversity, disturbs knowledge sharing and decision making. When members leave, knowledge gaps are created while new members bring in new knowledge. Since team members rely on the knowledge of others, it will take time before a team functions again (Akgun & Lynn, 2002). In a study executed by Smits et al (2004), differences with regard to team members tenure are negatively related to operating profits. Keck (1997) concluded that variation in team tenure has positive as well as negative effects on performance. These mixed results were also found by Carpenter (2002). The studies of Smith et al. (1994) and Kirkman et al. (2004) did not find a relationship team tenure diversity and performance. More recently, Hirst (2009) also did not find a relationship between diversity in team members tenure and team performance. Because of these inconsistencies, Van Knippenberg and Schippers 5

6 (2007) argued that the disparity in findings to the diversity performance relationship, as is evident in the previous discussion of the relationship between team tenure diversity and team performance, urges researchers to identify moderator or mediator variables that explain these inconsistencies in research findings. One variable that might explain the inconsistencies in the relationship between team tenure diversity and team performance is conflict. According to Pelled et al. (1999), diversity regarding highly job related attributes, such as team tenure diversity, is apt to have strong relationships with conflict. Job related attributes refer to the degree that certain attributes capture experiences and abilities. When teams are more diverse, it is likely that team members have diverse knowledge, experiences, abilities, and viewpoints which are relevant to tasks. Before teams are able to harmonize single team members ideas and solutions on a specific task, discussions and conflicts will be present. Thus, it is likely that increased levels of diversity between individuals on job related characteristics can result in conflicts within teams. Therefore, conflict is expected to mediate the relationship between team tenure diversity and performance (Pelled et al., 1999). Team tenure diversity and conflict Conflict is apt to have both positive and negative effects on team performance (Pelled et al., 1999). In order to explain these discrepancies in performance outcomes, conflict will be divided into four different types, namely task-, status-, relationship-, and process conflict. It is expected that each type of conflict could have its own unique relationship with team performance (i.e. Jehn, 1994; Jehn, 1997; Pelled et al, 1999; Bendersky & Hayes, 2010). In the upcoming section, the different effects and relationships between team tenure diversity, the four types of conflict, and team performance are cut into pieces, in order to explain the relationship between these variables more explicitly. It will be discussed why some of the four types of conflict could results in lower levels of team performance, whereas on the other hand conflicts could result in increased team performance. In the end, a mediation hypothesis will be provided. Task Conflict Task conflict is a condition in which group members disagree about task issues, including goals, key decision areas, procedures, and the appropriate choice for action (Jehn, 1994). Later on, Jehn described task conflict as an awareness of differences in viewpoints and opinions pertaining to a group task (Jehn & Mannix, 2001). Examples of task conflict are conflicts about the distribution of resources, procedures and policies, and judgments and interpretations of facts (De Dreu & Weingart, 6

7 2003). When people in a particular team differ in terms of team tenure, it is likely that these people have differences in work experiences, different skills, information, and education background. These differences in viewpoints, insights and knowledge, increase the likelihood that task conflicts will occur in comparison to teams that are low on team tenure diversity. Thus, it can be expected that team tenure diversity results in higher levels of task conflict, because of these individual differences. Unexpectedly, Pelled et al. (1999), did not found support for this relationship and suggest that team tenure diversity is not the important demographic driver of task conflict. Therefore, it is interesting to study the relationship again. Summarized, according to the information decision-making perspective, more diversity should result in higher levels of task conflict. This results in the following hypothesis: H1: Team tenure diversity is positively related to task conflict. Status Conflict Status conflicts are defined as disputes over people s relative status positions in their group s social hierarchy. Examples of these conflicts are conflicts about places or social positions in groups (Bendersky & Hays, 2010). The structural properties of status conflicts induce more competitive behaviors than do the other types on conflict, because status conflicts have longer-term consequences, implicate other group members more and have more distributive outcomes (Bendersky & Hays, 2010). Team members who are working in a team for quite a while are generally higher positioned in the group s social hierarchy than team members who recently joined the team. Therefore, people who are new in a team are aware of their lower social position in the team, and will probably, as a result of that, not give any rise to status conflicts to improve their position in the social hierarchy. On the other hand, teams with low tenure diversity, with team members started working in a team almost simultaneously, team members perceive themselves as similar. In order to gain a positive self identity, team members compare themselves to other team members on salient attributes. Status is one of such salient characteristics (Williams & O Reilly, 1998). Therefore, each of these similar team members will try to gain the highest status position within the team and members will therefore experience more status conflicts (Williams & O Reilly, 1998; van Knippenberg & Schippers, 2007). Summarizing; when team tenure diversity is low, people will compare themselves to others more easily, which could result in increased competition for the highest status position in the group. The opposite is expected to be true as well. More differences in terms of team tenure, will result in lower levels of status conflict. This results in the following hypothesis: H2: Team tenure diversity has a negative relationship with status conflict. 7

8 Relationship Conflict Relationship conflict is described as an awareness of interpersonal incompatibilities, which includes affective components like feelings of tension and friction. Relationship conflict involves personal issues such as dislike among team members and feelings like annoyance, irritation and frustration (Jehn & Mannix, 2001). Examples of relationship conflicts can be described as conflicts about personal taste, political preferences, interpersonal styles, and values (De Dreu & Weingart, 2003). Relational conflicts limit the information processing ability of a team, because team members spend time and energy on interpersonal aspects of the group, instead of on the job (Jehn, 1997). To explore the relationship between team tenure diversity and relational conflict, it may be interesting to look at the salience of social categorizations. Diversity can lead team members to distinguish others between us and them (Van Knippenberg, de Dreu, and Homan, 1999). This categorization, or putting people in (sub)groups, takes place on any attribute that is relevant for team members, also for team tenure. Team members with high team tenure may perceive themselves as different from team members with lower team tenure. When team tenure diversity is high, resulting in for instance a high versus a low tenure subgroup within the group, the distinction between us and them is most present. As a result of this social categorization, intergroup bias can occur. Intergroup bias refers to more favorable perceptions of the in-group (us) than out-group (them). This results into personal dislike, group cohesion, and relational conflicts (Williams & O Reilly, 1998). Thus, for teams with high team tenure diversity, the likelihood for categorization and intergroup bias is higher, in comparison to teams with low team tenure diversity. When this team tenure diversity is low, it is less likely that social categorization takes place, the presence of intergroup bias is low, and therefore, the likelihood that relational conflicts are present is low. Jehn et al. (1999) found support for this assumption. They concluded that social categorization diversity increased relational conflict in work teams. Also, Jehn et al. (1997) showed that teams with differences among team members have more relational conflicts compared to homogeneous teams. This results in the following hypothesis: H3: Team tenure diversity has a positive relationship with relational conflict. Process Conflict Process conflict is defined as an awareness of controversies about several viewpoints of how task accomplishment will proceed. Specifically, process conflict pertains to subjects of duty and resource allocation, such as who should do what and how much responsibility one should get. For example, 8

9 when team members have arguments about who is responsible for completing a specific task, they experience process conflict (Jehn & Mannix, 2001). When team members start working together, they may be allowed to focus on procedural and administrative features of the task they start working on. In these early phases, procedures and deadlines will be agreed upon, accepted and understood. Before teams reach agreement about their duties, deadlines, and procedures, it is likely that moderate levels of process conflict will be experienced (Jehn & Mannix, 2001). This suggests that groups with low tenure diversity should face more process conflicts, since they are working together from the beginning. The likelihood that process conflict occurs is higher in comparison to high tenure diversity teams, since in the low tenured teams team members altogether are more responsible for the set of actions, duties and responsibilities they have agreed upon in the early phases. In groups with more team tenure diversity, team members have started working in a group on different times. For these newcomers, procedures are already agreed upon by team members who work in this team from the early phases, and will therefore result in less process conflicts. The newcomers in a particular team will raise the level of team tenure diversity, but newcomers will not intensify conflicts about procedures, duties, responsibilities, deadlines, since these aspects are agreed upon in the early phases of the team. This line of reasoning is confirmed by a study of Vanaelst et al. (2006). They found that newcomers in a team, who increase the level of tenure diversity, do not bring in different views on how to do business. Therefore, the following hypothesis is stated: H4: Team tenure diversity has a negative relationship with process conflict. Conflict & team performance Previously, a description has been given on how team tenure diversity is positively or negatively related to the four types of conflict. The following section will describe how the four types of conflict are related to team performance. Task Conflict As aforementioned, task conflicts occur in situations in which team members hold different perspectives on task issues, goals, key decision areas, procedures, and appropriate choices for action (Jehn, 1994). Opposite to other types of conflict, task conflict is seen as beneficial for team performance. When people engage in task conflict, people confront issues, learn to take different perspectives, and need to be creative. When task conflict is absent, teams might not realize that inefficiencies exist (De Dreu & Weingart, 2003). 9

10 In the study of Pelled et al. (1999), they report that task conflict had a positive association with task performance. Task conflict evidently fosters a deeper understanding of task issues and an exchange of information that facilitates problem solving, decision making, and the generation of ideas. This result is in line with the information processing perspective (Van Knippenberg & Schippers, 2007). However, this view is rejected by De Dreu and Weingart (2003) in their meta-analysis. Task conflict is, opposite to as expected, not beneficial for team performance. Rather, they suggest that whereas little task conflict may be beneficial, these positive effects break down rapidly as conflict becomes more intense. Because of these high intensities, cognitive load increases, information processing impedes, and team performance suffers. According to this view, too much task conflict hinders team performance. This finding is also reported by Jehn (1995), concluding that high levels of task conflict interfered with group performance. Team members became overwhelmed with the amount of conflicting information and continuously became side-tracked and lost sight of the main or original goal of the discussions, resulting in lower performance. All in all, this information processing perspective suggests a curvilinear correlation between task conflict and team performance: Low levels of task conflict stimulates information processing, but as task conflicts intensify, the cognitive system shuts down, information processing impedes, and team performance suffers (De Dreu & Weingart, 2003). Taken this into account, the following hypothesis is formulated: H5: Task conflict has an inverted U relationship with team performance. Status Conflict As aforesaid, status conflict is concerned with team members relative positions in the social hierarchy of their team. The structural properties of status conflicts encourage more competitive behaviors than do the other types of conflict, for the reason that status conflicts have longer-term consequences, involve other team members more and have more distributive outcomes (Bendersky & Hays, 2010) Bendersky and Hayes (2010) concluded in their study that status conflicts seemed to produce particularly intense and competitive exchanges that resulted in less information sharing among team members. Research shows that competition inhibits information sharing among group members (Toma & Butera, 2009). In these competitive exchanges, team members withheld information for others, interrupted each other to prevent others from sharing competitive viewpoints, failed to acknowledge valid information that was shared by others, and, at times, withdrew from a discussion altogether. 10

11 Thus, status conflicts may be particularly detrimental to group performance because they negatively impact information sharing among team members (Bendersky & Hays, 2010). This results in following hypothesis: H6: Status conflict has a negative effect on team performance. Relational Conflict Earlier, relationship conflict was described as perceived perceptions of incompatibilities between individuals within a team, which includes affective components like tension and friction. It is not expected that relationship conflict is beneficial for team performance. However, low levels of this type of conflict are necessary to develop familiarity, in order to have positive interactions in the future (Jehn & Mannix, 2001). When team members have a relational conflict, this can result in cognitive interference. This means that team members may not take the relevant information and different points of view into consideration. Next to that, relational conflicts can make team members reluctant to share ideas, or listen to the ideas and information of others (Jehn, 1994). Van Knippenberg and Schippers (2007) have similar viewpoints. They state that when team members experience relational conflicts, they will hesitate to share their information and knowledge, resulting in lower performance. Finally, a relationship conflict takes time. Time spent on these conflicts is better spent on productive behaviors (Jehn, 1994). However, not in line with the expected, Pelled et al. (1999) did not find evidence that relational conflict had negative consequences for performance. In order to summarize results from previous research, De Dreu and Weingart (2003) executed a meta-analysis on the relationship between relationship conflict and team performance. They concluded that relational conflict had a significant negative effect on team performance, which is congruent with the information decision-making perspective. This results in the following hypothesis: H7: Relationship conflict has a negative effect on team performance. Process Conflict Process conflict occurs when team members disagree about how to accomplish a certain task (Jehn, 1992). According to Jehn & Mannix (2001), process conflict has not been examined much. Following conflict literature, the relationship between process conflict and decision making has some theoretical evidence. Teams spending too much time about debating how to accomplish their goals and which strategy should be used, fail to use their time efficiently. This is referred to as process loss, detrimental to team performance. As a result, process conflict limits the perception that decisions 11

12 are made in an efficient manner (Steiner, 1972). This theoretical reasoning is confirmed by several empirical studies. Passos and Caetano (2005) concluded that process conflict had indeed a negative relationship with decision making effectiveness. In a study by Jehn (1992), process conflict is associated with decreased productivity. Later on, Jehn (1997) executed a qualitative study to the effects of conflicts on team performance and concluded that process conflict has a direct negative effect on team performance. Next to that, Matsuo (2006) concluded that process conflict has a negative effect on team s innovativeness. Summarized, the following hypothesis is stated: H8: Process conflict has a negative effect on team performance. In the previous section, the relationships between team tenure diversity and conflict and the relationships between conflict and team performance are enlightened. Finally, this study focuses on if and to what extent conflict mediates the relationship between team tenure diversity and team performance, since this relationship is still open to doubt as was presented in the beginning of this paper (Van Knippenberg & Schippers, 2007). Therefore, the following mediation hypothesis is provided, tested for each type of conflict separately. H9: Conflict mediates the relationship between team tenure diversity and team performance. Conceptual model The left side of this model shows the first four hypotheses and indicates that differences with regard to team tenure results in higher levels of task conflict, and results in lower levels of status-, relational-, and process conflict. The right side of the model describes the following four hypotheses, 12

13 and indicates that status-, relational-, process-, and high levels of task conflict are expected to hinder team performance, whereas low to medium levels of task conflict seem to stimulate team performance. The dotted line indicates an expected effect between team tenure diversity and team performance, mediated by any type of conflict. Methods Sample The sample of this study comprised of 345 individuals working in 44 different R&D teams and also in six different firefighting teams. These teams were collected in six different organizations. On the one hand, the prominent daily activities of these individuals are activities with respect to research and development. On the other hand, and therefore just as valuable, activities in which firefighting teams face new situations in different circumstances and have to act creatively in order to encounter problems. Initially, 345 online surveys were sent to 50 teams. Team leaders or team supervisors were also asked to fill out this questionnaire in order to compare scores between team members and team leaders. A reminder was sent for each individual who did not fill-out the questionnaire within four weeks. Four weeks later, the second and final reminder was sent via . Also, team supervisors were instructed to persuade team members in order to increase the response rate. Eventually, the response rate was 48.4%, consisting of 167 individuals divided among 36 teams. The final sample consisted of 77.4% males and 22.6% females. The average age was 38.4 years (SD=8.75). Almost 97% of the respondents worked on a fulltime basis (32 hours or more), with an average organizational tenure of 8.66 (SD=8.56) years and an average team tenure of 2.04 (SD= 2.04) years. Measures Team Tenure Diversity. Team tenure diversity is measured by calculating the standard deviation in tenure for each team, higher standard deviation indicates more team tenure diversity. Single team members tenure is measured by asking how long the team member is working in his or her team, measured in years and months. Team performance. Team performance was measured by asking team members and team leaders about the performance of their own team on a 7-point Likert scale (1=poor, 7=excellent), using six 13

14 performance dimensions. These dimensions are efficiency, quality of innovations, adherence to schedules, adherence to budgets, ability to resolve conflicts, and overall performance (Ancona & Caldwell, 1992). The following question was asked: How would you rate the performance of your team on the following dimension. Factor analysis revealed that team performance is comprised of one single component (see Appendix 2). The Cronbach s Alpha of this scale was Conflict Status conflict was measured by using the four item scale developed by Bendersky and Hays (2010). These items were answered on a 7-point Likert scale, anchored by 1= None and 7= A lot. One example of these items is; My team members experienced conflicts due to members trying to assert their dominance. Task conflict was measured by using four items of the scale developed by Jehn (1995). These items were answered on a 7-point Likert scale, anchored by 1= None and 7= A lot. One example of these items is; How often do people in your work unit disagree about opinions regarding the work being done?. Relational conflict was measured by using four items from Jehn (1995). These items were answered on a 7-point Likert scale, anchored by 1= None and 7= A lot, was used. One example of these items is; How much friction is there among members in your work unit. Process conflict was measured by using three items from Shah and Jehn (1993). Also, a 7-point Likert scale, anchored by 1= None and 7= A lot, was used. One example of these items is; How frequently were there disagreements about who should do what in your work group. Factor analysis revealed that conflict is comprised of three different components, corresponding with the survey scales of task conflict, status conflict, and relational conflict (see Appendix 2). The Cronbach s Alpha of these scales are for task conflict, for status conflict, and for relational conflict. Cronbach s Alpha s must be higher than 0.7 in order to have reliable outcomes on team level (Pallant, 2007). Unfortunately, the 3-item process conflict scale was not very reliable having a Cronbach s Alpha score of.566. Therefore, it was decided to remove process conflict from this study. Table 1 presents an overview about the measurement of the variables in this study. Data Analysis Data was collected from individuals that belong to workgroups, within the same organization. Teams are considered a team when it consists of at least 3 individuals. Since this study focuses on diversity within teams, individual responses were aggregated to team scores, resulting in an average team 14

15 score. These scores had to meet the requirements of aggregation, which are sufficient scores on ICC1 (the extent to which individual raters in a group are substitutable) and ICC2 (estimation of the reliability of the group means) (Bliese, 2000). ICC2 values above 0.5 are acceptable, ICC2 values above 0.7 are considered good (Klein et al, 2000). Based on these conditions, data was considered reliable to aggregate. Table 1. Number of items per scale, response categories, Cronbach s Alpha, ICC1/ICC2. N=167 =36 teams Survey scale No. of items No. of answering categories Cronbach s Alpha Team Performance Task conflict Status conflict Relational conflict Process conflict NA NA ICC1 ICC2 Additionally, it was tested how scores were correlated between team members and team leaders, in order to test whether team leaders could be considered as team members. Therefore, correlations between the data of team members and team leaders have been calculated per questionnaire scale. Table 2 shows that scores for team members task conflict are unrelated to team leaders perceptions of task conflict (r =.192, ns). This is also the case for team members and team leaders with respect to status conflict (r =.340, ns). Therefore, for both these types of conflict, hypotheses will be tested for team members and team leaders separately. On the other hand, scores between team members and team leaders with respect to relational conflict are correlated (r =.475, p <.05). Therefore, team members and team leaders are considered as one. For testing the hypotheses in this study, which posited that the four types of conflict would act as mediators in the relationship between team tenure diversity and team performance, the standard procedure for testing mediating effects is used and consists of three steps, as described by Baron and Kenny (1986). The first step is regressing conflict (mediator) on team tenure diversity (independent variable). The second step is regressing team performance (dependent variable) on team tenure diversity (independent variable). The third step is regressing team performance (dependent variable) on both team tenure diversity (independent variable) and conflict (mediator variable) (Baron & Kenny, 1986: p1177). 15

16 To establish mediation, the following three conditions must hold: First, the independent variable team tenure diversity must affect the mediator conflict(s) in the first equation. Second, the independent variable team tenure diversity must be shown to affect the dependent variable team performance in the second equation. And third, the mediator conflict(s) must affect the dependent variable team performance in the third equation (Baron & Kenny, 1986: p1177). For each type of conflict, a separate regression analysis was used. For the relationship between team tenure diversity and task conflict, which hypothesized a curvilinear relationship, the curve estimation option was used to execute a curve fit for this relationship (Pallant, 2007). Finally, significance for the indirect effect of the independent variable on the dependent variable via the mediator was tested by using the Sobeltest. Control variables The first control variable is group longevity, which is defined as the average time group members have spent working together. It is stated by Katz (1982) that groups with increased longevity became increased isolated from important informational sources both outside and within the organization. The second control variable is age diversity. Age diversity is operationalized as the mean standard deviation score. These variables were taken into account in order to compare whether the results for team tenure diversity would change when these variables were added into the model. Results In this section, the results of this study are shown. First, means, standard deviations, and correlations for the variables used in this study are presented in Table 2. Second, the results for the different types of conflict and how these relate to team tenure diversity and team performance are described, followed by the mediation effects per type of conflict. Within the regression tables, model 1 stands for the regular analyses, in model 2 the control variables are added. Table 2 shows that team members conflict types are somehow correlated. It is stated that correlations higher than 0.8 are problematic (Kennedy, 1979, in Pelled et al., 1999: p15). In this survey, relational conflict and task conflict members have the highest correlation (r = 0.786, p <.05), which is somewhat problematic. 16

17 Table 2. Means, standard deviations, and correlations among variables 1.Team Performance Mean S.D Team Tenure Diversity Task Conflict member * Task Conflict leader Status Conflict member * * Status Conflict leader Relational Conflict ** * * Group Longevity * * Age Diversity 7, * * p < 0.05, **p <0.01 Team tenure diversity, task conflict and team performance (H1 and H5) For hypothesis 1, it was predicted that team tenure diversity was positively related to task conflict. Table 3, indicates that there is no significant relationship between team tenure diversity and task conflict, as experienced by team members (β = -.032, ns). Furthermore, the results indicate that task conflict experienced by team members does affect team performance significantly (β = -.447, p <.05) Higher levels of task conflict decreases team performance. However, the relationship between task conflict and team performance is not U inverted, which rejects hypothesis 5. No differences in the results were found when the control variables were added into the model (model 2), respectively (β =-.095, ns and β = -.472, p <.05). Table3. Standardized regression coefficients, R square, R square change and F-values Team Performance Task Conflict Member Model Team Tenure Diversity Task Conflict Member -.447* -.472* Group Longevity.679*.134 Age Diversity R² R² F * *p <.05 17

18 Additionally, it is evident from the results in Table 4 that hypothesis 1 is also rejected for task conflict as experienced by team leaders (β =-.070, ns). No relationship was found between team tenure diversity and task conflict, as experienced by team leaders. Thereby, no relationship was found between task conflict and team performance (β = -.331, ns) as presented in Table 4, also rejecting hypothesis 5 for team leaders. No differences in the results were found when the control variables were added into the model (model 2), respectively (β = -.103, ns and β = -.336, ns). Table4 Standardized regression coefficients, R square, R square change and F-values Team Performance Task Conflict Leader Model Team Tenure Diversity Task Conflict Leader Group Longevity.648*.097 Age Diversity R² R² F *p <.05 Team tenure diversity, status conflict and team performance (H2 and H6) Regarding hypothesis 2, it was predicted that team tenure diversity was negatively related to status conflict. As illustrated in Table 5, team tenure diversity has no significant relationship with status conflict for team members (β =.242, ns). For status conflict, the results in Table 5 show that higher levels of status conflict as experienced by team members has a negative relationship with team performance (β = -.531, p <.05), indicating that higher levels of status conflict results in lower levels of team performance. This confirms hypothesis 6, stating that status conflict had a negative effect on team performance. No differences in the results were found when the control variables were added into the model (model 2), respectively (β =.374, ns and β =-.499, p <.05). 18

19 Table5 Standardized regression coefficients, R square, R square change and F-values Team Performance Status Conflict Member Model Team Tenure Diversity Status Conflict Member -.531* -.499* Group Longevity Age Diversity R² R² F 4.668* 3.734* *p <.05 Additionally, Table 6 illustrates that team tenure diversity has no significant relationship with status conflict as experienced by team leaders (β =.157, ns). The results provide no support for hypothesis 2. Also, no effects are found between status conflict and team performance (β = -.362, ns), as is presented in Table 6. This rejects hypothesis 6 for team leaders. No differences in the results were found when the control variables were added into the model (model 2), respectively (β =.157, ns and β=.354, ns). Table6 Standardized regression coefficients, R square, R square change and F-values Team Performance Status Conflict leader Model Team Tenure Diversity Status Conflict leader Group Longevity Age Diversity R² R² F *p <.05 19

20 Team tenure diversity, relational conflict and team performance (H3 and H7) For relational conflict, it was expected that team tenure diversity had a negative relationship with relationship conflict. As can be observed in Table 7, this study did not found a significant relationship between these variables (β =.149, ns), rejecting hypothesis 3. Additionally, a negative significant relationship was found between relational conflict and team performance (β = -.460, p <.05), confirming hypothesis 7. Higher levels of relational conflict within teams result in lower levels of team performance. No differences in the results were found when the control variables were added into the model (model 2), respectively (β = -.070, ns and β =-.588 p <.05). Table7 Standardized regression coefficients, R square, R square change and F-values Team Performance Relational Conflict Model Team Tenure Diversity Relational Conflict -.460* -.588* Group Longevity.823*.352 Age Diversity R² R².227*.179* F 4.706* 6.388* * *p <.05 Summarizing the results, team tenure diversity does not result in any type of conflict. With regard to conflict, any type of conflict studied in this survey has a negative impact on team performance. For team members, this impact is significant. Team tenure diversity on team performance, mediated by conflicts (H9) In order to test for mediation, the standard procedure as proposed by Baron and Kenny (1986) has been used, using a Sobel test. The followed steps in this procedure were described in the method section. The results indicate each type of conflict, whether it was divided into team members and leaders separately or not, did not have significant mediating effect in the relationship between team tenure diversity and team performance. This rejects hypothesis 9 for each type of conflict. Conflict does not mediate the relationship between team tenure diversity and team performance. These results are presented in Table 8. For further details, see appendix 3. 20

21 Table 8. Sobel test for mediation in the relationship between team tenure diversity and team performance Sobel test P-value Relationship conflict Status conflict Member Status conflict Leader Task conflict Member Task conflict Leader * p <0.05 Control variables When testing for control variables, it was found that team tenure diversity and group longevity were highly correlated (r = 0.742, p <.05). According to Baron and Kenny (1986), it is desirable that a moderator variable is unrelated to the criterion and predictor variable in order to provide a clear interaction term. Since group longevity needs to be tested as a control variable, this test cannot be executed without the occurrence of multicollinearity. Therefore, it may be assumed that the previously presented model 2 analyses are somewhat distorted. In order to overcome this problem, model 1 analyses were executed again, replacing team tenure diversity for group longevity to test whether these analyses have different or similar outcomes. Results of these tests indicate that group longevity does have a positive significant relationship with relational conflict (β = 0.349, p <.05). In teams with higher levels of group longevity, team members experience more relationship conflicts. In this sense, group longevity differs in comparison to team tenure diversity. For task conflict member (β =0.107, ns), task conflict leader (β =0.064, ns), status conflict member (β =0.118, ns), and status conflict leader (β =0.152, ns), no effects were found. This is in accordance with the previously model 1 analysis. Interestingly, a significant relationship between group longevity and team performance (β =.467,p <.05) has been found, opposite to the relationship between team tenure diversity and team performance. In order to examine the influence of age diversity as a control variable in the second model, model 2 analyses were executed again without group longevity as control variable in the same model. Results of these analyses show no differences in outcomes with the previously described model 2 analyses (see appendix 4). Still, no effects are found for the relationship between team tenure diversity and conflict. Task-, status-, and relational conflict as experienced by members are still detrimental to team performance. 21

22 Discussion This study gains more insight in the mediating role of conflicts in the relationship between team tenure diversity and team performance, since previous results from studies to this relationship are inconclusive. Also, more insights were needed to improve understanding of mediators in the diversity performance relationship. Therefore, the following research question was investigated: To what extent do the different kinds of conflict mediate the relationship between team tenure diversity and team performance? All conclusions are based on the selected sample, containing 167 individuals among 36 teams. The results suggest that the three different types of conflict do not mediate the relationship between team tenure diversity and team performance. So, conflict is not the type of mediating variable that explains different outcomes in the team tenure diversity performance research field. Apparently, team tenure diversity is not a predictor of team performance in this sample. Team tenure diversity does not affect team performance significantly, nor does team tenure diversity have significant effects on any type of conflict. However, the different kinds of conflict do influence performance significantly, all types of conflict experienced by team members are detrimental to team performance. Higher levels of task-, status-, and relationship conflict result in significant lower levels of team performance. As mentioned before, team tenure diversity does not seem to be an important type of diversity that seems to stimulate or hinder team performance. Nevertheless, how long a group has worked together does have a relationship with team performance. Also, when team compositions remain stable over time, relationship conflicts will occur. Explanations for these findings are presented below, as well as limitations which might have affected the outcomes. In the end, some practical implications are presented along with the theoretical- and research implications. Team tenure diversity and conflict Team tenure diversity did not have an effect on the level of task conflict, experienced by members and leaders. This is opposite to as expected with regard to the information decision-making perspective, stating that differences in viewpoints, insights and knowledge increases the likelihood for the occurrence of task conflicts. Apparently, the differences between team members in team tenure do not lead to differences in viewpoints, insights and knowledge. This result was also found by Pelled et al. (1999). They stated that team tenure diversity is not the important demographic driver of task conflict. 22

23 Furthermore, team tenure diversity also did not have a negative relationship with status conflict. It was predicted, according to the social categorization perspective, that similarities between team members would result in more status conflict, since similar team members will compare themselves more easily with similar others (Williams & O Reilly, 1998). Unexpectedly, this competition for increasing ones position in the social hierarchy did not take place, at least not when team members compare themselves to other with respect to tenure differences. Finally, team tenure diversity did not have a significant relationship with relational conflict. It was expected, according to the social categorization perspective, that more differences between individuals will result in more relational conflicts. Apparently, the salience of team tenure is not important for individuals for comparing themselves to others. Also, it can be reasonable to believe that individuals within R&D teams should have similar qualifications and competencies as their colleagues. Therefore, team members perceive themselves as similar in-group members more easily, which in turn decreases the likelihood for relational conflicts to occur. Overall, team tenure diversity does not have a relationship with any type of conflict. Apparently, and contradictory to Pelled et al. (1999), there are other job-related characteristics that are important for conflicts to occur within diverse R&D teams. Conflict and team performance According to the results, task conflict affects team performance in a negative way. Higher levels of task conflict results in performance losses. It was expected according to the meta-analysis by De Dreu and Weingart (2003), that there would be an inverted U relationship, stating that low levels of task conflict should stimulate team performance, whereas higher levels of task conflict should impede team performance. This curvilinear relationship was not found in this study. These findings go against current thinking that little task conflict is beneficial for team performance (De Dreu & Weingart, 2003). Low levels of task conflict seem to hinder team performance as well. Possibly, any level of task conflict interferes with team performance for R&D teams. Because of conflicting information, viewpoints and insight, too much time and effort is lost to be beneficial for increased team performance. Furthermore, status conflict seems to affect team performance in a negative way. As expected, higher levels of status conflict are detrimental to team performance. Bendersky and Hays (2010) concluded in their study that status conflicts results in competitive exchanges, withholding information, and resulted in less information sharing. Since, sharing information is particularly important in R&D teams and fire fighting teams, the lack of sharing information is obviously related 23