**1. Introduction**

Multiparty systems (MPSs) are social systems, composed of several organizations or their representatives that interact in order to make decisions or address complex issues with major social impact (Curs,eu and Schruijer 2017). Such issues include sustainable urban development, natural resource managemen<sup>t</sup> (including water use), or dealing with climate change. Therefore, MPSs bring together various stakeholder groups (typically more than three parties) that engage within, as well as between, group interactions in an attempt to find integrative solutions to these complex issues (Curs,eu and Schruijer 2018). MPSs often face significant challenges in reaching the desired outcome, as they embed substantial diversity (e.g., interests, backgrounds, and power asymmetries) (Vansina and Taillieu 1997; Fle¸stea et al. 2017) on the one hand, and a grea<sup>t</sup> degree of interdependence on the other hand (e.g., the sustainable and comprehensive solutions can be reached only by building on integrative actions).

In some cases, MPSs can have a formal governance structure (especially in situations in which formal representatives of the state or governmen<sup>t</sup> are part of the MPS), ye<sup>t</sup> most of the times the governance of MPSs emerges from the interactions, joint practices, and efforts aimed at unraveling and working with the interdependencies among the stakeholders that compose the system (Bouwen and Taillieu 2004). Such an emergen<sup>t</sup> governance is often hindered as the stakeholders that join the system may bring in frictional relational histories, misunderstandings, or false assumptions that lead to stereotyping and negative behaviors and impede the functioning of the whole system (Schruijer 2006). Due to the relational tensions, oftentimes, some of the stakeholders may ge<sup>t</sup> marginalized

or even be excluded from the system. In such a case, these stakeholders cannot achieve their aims. Moreover, the system itself may lose its integrity and ultimately fails to achieve its purpose. Therefore, goal achievement motivates stakeholders to be actively engaged in the relational dynamics of the MPS. In social network terms, stakeholders seek to establish and maintain advantageous central positions in the social networks that capture the relational landscape of the MPS. A key question is: what makes a stakeholder central in the collaboration network of an MPS?

Popular business literature acclaims trust as a social lubricant and scholarly research shows that trust fosters collaboration in work teams (Costa et al. 2018), decreases conflict (Curs,eu and Schruijer 2010) and facilitates the development of collaborative relations in MPSs (Vansina and Taillieu 1997). Organizational research shows that trust is more likely to emerge in decentralized (organic) rather than hierarchical organizational structures (Costa et al. 2018). Moreover, social network research claims that knowing who trusts whom accurately predicts who will interact with whom and in what way (Kilduff and Brass 2010). Trust however is a multifaceted (e.g., cognitive, affective, relational, etc.) and multilayered (e.g., interpersonal, intra-group, inter-group, etc.) phenomenon and its relationship with actors' structural positions in social networks is complex. Building on social interdependence theories (Deutsch 1949; Holmes 2002), we set out to explore the role of trust expectations as antecedents of network centrality in MPSs. We build on social comparison and self-enhancement arguments (Kwan et al. 2004) to argue that at the onset of social interactions in MPSs, stakeholders engage in social comparison (me versus others) and the emerging trust self-enhancement (trust in myself versus trust in others) ultimately shapes one's centrality in the collaboration network in MPSs. In other words, we claim that one's centrality in social networks originates from trust expectations based on the social comparison processes at the onset of social interactions.

In this paper, we build on the social network approach to argue that an MPS can be conceptualized as a network of groups that interact with each other in order to jointly define and solve the task at hand. We extend the research on MPSs in several ways. First, our exploration is among the first attempts to explore the dynamics of network centrality using sequential evaluations of network perceptions collected at four points during a behavioral simulation. We use a longitudinal data collection approach to test the effect of trust self-enhancement on the emergence and evolution of network centrality. Second, we employ a socio-structural view and a network aggregation procedure in which we combine individual perceptions of network centrality to obtain group level estimates that are representative for each stakeholder group. As such, our paper provides an empirical illustration of how social network procedures can be used to understand the dynamics of MPSs. Third, we explore trust self-enhancement as one of the cognitive antecedents of the structural position in the MPS network. Using this self-enhancement approach to trust, we move beyond the traditional view that trust is the property of an agen<sup>t</sup> and we explore trust as emergen<sup>t</sup> from social comparison processes in a context of social relations.

### **2. Theory and Hypothesis**

### *2.1. A Social Network Approach to MPSs*

MPSs bring together various stakeholder groups with the goal to address complex issues, oftentimes resulting in decisions with far-reaching implications (i.e., sustainability decisions, designing new laws, etc.) (Curs,eu and Schruijer 2017). The decision tasks that such systems face are often vague at the onset of the stakeholders' interactions and the outcome is difficult to predict from the initial expectations and aspirations each stakeholder has. In order to be successful, the stakeholders in the MPS are compelled to engage in collaborative processes and are motivated to establish and maintain a central position in the relational landscape of the MPS. That is, each stakeholder is expected to actively participate and share its interests, views, and concerns regarding the topic at hand. Moreover, as the views and interests expressed during interactions are often diverse, the stakeholders are required to engage in and integrate the task disagreements, in search for the integrative potential of the situation (Gray 1989; Curs,eu and Schruijer 2017). In doing so, the stakeholders also need to handle the differences regarding their identities, status, and power (Schruijer 2006), and work with the various perceptions and behavioral expectations they hold regarding both one's own group and the other groups in the system (Curs,eu and Schruijer 2018).

So far, the dynamics of MPSs was explored under a variety of frameworks, ranging from psychodynamics (Schruijer and Vansina 2008), to relational (Gray 1989; Schruijer 2008) and process-based approaches (Gray 1985). In this paper, we take a structural approach to MPSs and argue that MPSs are social networks, in which stakeholder groups are represented by nodes that are interconnected by an evolving web of social ties. In this framework, the MPS dynamics is captured by the structural changes that occur in the nodes and tie characteristics during social interactions (Snijders 2001). In other words, in a structural approach, the evolution of the social network structure in an MPS captures the dynamics of the relational landscape emerging in such a complex system.

Social capital research brought extensive evidence on the value of social ties, linking one's position in the network to various beneficial outcomes such as: power (Brass and Burkhardt 1993; Kilduff and Krackhardt 1994), leadership (Brass and Krackhardt 1999; Pastor et al. 2002), or performance (Hansen 1999; Tsai 2001). Out of the various metrics that describe an actor's structural position in the system, centrality refers to the degree to which a node (a stakeholder group in this case) is connected to all the other nodes in the network (Westbay et al. 2014). Collaboration centrality, in particular, indicates the number of collaborative relations between a stakeholder group and the other groups in the system. We used two indicators of network centrality, namely betweenness and closeness. Betweenness centrality refers to the number of times that a stakeholder in the system connects other stakeholders (pairwise) that are not directly in contact in the network (Freeman 1979). It is a measure of a bridging role in the MPS. On the other hand, closeness centrality refers to how close a node is from all the other nodes in the system (Freeman 1979). A stakeholder with high closeness centrality is situated in the middle of the MPS network and well connected with the rest of the stakeholders.

A stakeholder group that has a central position in an MPS is likely to be more influential and efficient in working at the multiparty and own agenda, as compared to a peripheral actor. It benefits from the multiple exchanges with other groups within the system such that it has greater access to information, support, and other resources received through the social ties (Oh et al. 2004). A stakeholder that is on average closer to the other stakeholders in the system (i.e., it has a high level of closeness centrality) can gather useful information more easily, while it can also more readily communicate its interests throughout the network and work on its agenda. Similarly, a stakeholder with high betweenness centrality plays the role of a broker, facilitating the information flow between other unconnected nodes in the MPS (Burt 1995). As previously discussed, openly discussing vested interests and concerns (i.e., handling task disagreements) among all stakeholders in the system, as well as solving relational conflicts, is a requirement for a successful collaboration (Curs,eu and Schruijer 2017). On the other hand such a stakeholder can also act as a gatekeeper, blocking the information flow in the network (Burt 1995). Due to the dependency of others, on the stakeholders with high betweenness centrality, the latter is often considered an indicator of the power and influence these actors have in an MPS (Krackhardt 1996). In other words, given the high degree of interdependence experienced by stakeholders in MPSs, seeking a central position in the collaborative process is an advantageous strategy for maintaining one's status, power, and influence in such systems.

### *2.2. Trust Self-Enhancement and Centrality in MPS Systems*

Trust or perceptions of trustworthiness refer to an individual or shared group belief that another stakeholder (individual or group) is honest, reliable (i.e., makes efforts to uphold commitments), and fair i.e., will not take advantage given the opportunity) (Cummings and Bromiley 1996; Zaheer et al. 1998). Whether within-group or between groups, trust is therefore a lubricant for social relations. Abundant research showed that trust increases cooperation (and cooperation further increases trust in a spiral effect (Ferrin et al. 2008), and it does so even in the absence of authority relations (Bradach and

Eccles 1989), itfosters information sharing and reduces the need to monitor others' behaviors (Curall and Judge 1995; Uzzi 1997).

To summarize, conventional theorizing of trust and social networks suggests that trust in others is a key ingredient for cooperation and communication (Rousseau et al. 1998). In other words, if stakeholders trust other stakeholders, they will be inclined to reach out, establish ties, cooperate, and ultimately increase their collaborative centrality. However, as argued by Edelenbos and van Meerkerk (2015), "the relations between connective capacity, trust and boundary spanning are not unproblematic" (p. 27) as generalized trust in others could also generate lock-in effects and ultimately isolate stakeholders in sparse ego-centric social networks and decrease their network centrality. In an exploration of social networks emerging in a water governance context (in the U.S. National Estuary Program), Berardo (2009) showed that if a particular stakeholder trusted another party, they did not seek to establish ties with additional parties in the system that were trusted by their trustee. However, if the initial level of trust towards a party was low, stakeholders made sure that they were accurately informed by seeking input from all parties in the system. Berardo (2009) suggests that the network behavior of stakeholders with a generalized lack of trust in others could be driven by self-defense and motivate these (non-trusting) stakeholders to acquire a central position in the network, in order to be well informed and establish (or maintain) a strategic advantage. We argue that trust self-enhancement is actually the driving mechanism explaining one's network centrality. Network behavior is driven by social comparison, and if a stakeholder has a substantial amount of self-trust and rather low trust in others (high trust self-enhancement and high group distinctiveness), they will tend to establish and maintain a large number of social ties and become a central actor in the network and acquire more power.

The role of trust self-enhancement in MPSs is grounded in the extension to the intergroup interactions of the expectation states theory (Berger et al. 1974; Berger et al. 1977). In line with this theory, the stakeholder groups form expectations about how much they trust themselves and the other stakeholders, as well as their collaborative intentions. Before the groups have the chance to interact with one another, they build a generalized anticipation related to the trustworthiness and collaborativeness of the other stakeholders in the system (Curs,eu and Schruijer 2018). Trust self-enhancement, as we argued before, increases group distinctiveness and the motivation to establish and maintain an advantageous position in the MPS social network. Therefore, trust self-enhancement becomes a basis for expected and real status and prestige differences among stakeholders (Berger et al. 1974; Berger et al. 1977). Given the high interdependence experienced in MPSs, trusting oneself more than others may foster self-interest and motivate stakeholders to seek contact with as many stakeholders as possible in order to maintain a sense of control and a high group distinctiveness. We argue that trust self-enhancement increases stakeholders' expectations to achieve a central network position fosters their collaborative efforts and ultimately influences the real experienced centrality in the MPS (as indicated by betweenness and closeness centrality).

Social identity and social categorization theories (Tajfel and Turner 1979) state that social categorization ("us" versus "them") is associated with in-group valorization (i.e., ascribing positive intentions and qualities to in-group members) and out-group devaluation (i.e., assigning negative qualities and intentions to out-group members). We argue that trust self-enhancement (i.e., a difference in the level of perceived trustworthiness of "our" group versus the other groups operating in the system) is likely to arise and point towards a self-enhancement inter-group strategy (i.e., we perceive "our" group to be more trustworthy compared to the way we perceive the other groups in the system). In other words, trust self-enhancement motivates the groups to seek and maintain a central position in the collaboration network in order to maintain their distinctiveness.

Therefore, our study investigates the role of trust self-enhancement in stakeholders' centrality in the social network that emerges in MPSs as these stakeholders seek agreemen<sup>t</sup> in a decision situation. Moreover, ones' expectations of collaboration centrality will sequentially predict the centrality of that stakeholder in the social network as intergroup interactions progress. *We therefore hypothesize that:*

**Hypothesis 1 (H1):** *Trust self-enhancement has a positive influence on the perceived stakeholder centrality in the social networks across time*.
