Do social identity and cognitive diversity correlate in environmental stakeholders? A novel approach to measuring cognitive distance within and between groups

Groups with higher cognitive diversity, i.e. variations in how people think and solve problems, are thought to contribute to improved performance in complex problem-solving. However, embracing or even engineering adequate cognitive diversity is not straightforward and may even jeopardize social inclusion. In response, those that want to promote cognitive diversity might make a simplified assumption that there exists a link between identity diversity, i.e. range of social characteristics, and variations in how people perceive and solve problems. If this assumption holds true, incorporating diverse identities may concurrently achieve cognitive diversity to the extent essential for complex problem-solving, while social inclusion is explicitly acknowledged. However, currently there is a lack of empirical evidence to support this hypothesis in the context of complex social-ecological systems—a system wherein human and environmental dimensions are interdependent, where common-pool resources are used or managed by multiple types of stakeholders. Using a fisheries example, we examine the relationship between resource stakeholders’ identities and their cognitive diversity. We used cognitive mapping techniques in conjunction with network analysis to measure cognitive distances within and between stakeholders of various social types (i.e., identities). Our results empirically show that groups with higher identity diversity also demonstrate more cognitive diversity, evidenced by disparate characteristics of their cognitive maps that represent their understanding of fishery dynamics. These findings have important implications for sustainable management of common-pool resources, where the inclusion of diverse stakeholders is routine, while our study shows it may also achieve higher cognitive coverage that can potentially lead to more complete, accurate, and innovative understanding of complex resource dynamics.


The case of Western Baltic cod
Cod of the western Baltic Sea (Fig. S1) is not only ecologically of great importance (i.e. predator-prey relationships), also the commercial fishery, which is dependent on this species, shapes the area of the North German Baltic Sea coast and thus provides a high sociocultural variety. In addition, tourism and especially recreational fisheries are main components of the region, i.e. anglers come from all over Germany to the Baltic Sea coast to catch for cod and thus have a great influence on the characteristics of this region.
However, the state of the stock is currently outside safe biological limits (ICES, 2019). In order to ensure a sustainable management of commercial fish stocks like cod in the Western Baltic Sea, the European Union (EU) has implemented various management measures within the framework of the Common Fisheries Policy (EC, 2013;EC, 2016). These include, in particular, the so-called total allowable catch quotas (i.e. TACs). In the specific case of Western Baltic cod and due to its low stock size, also recreational fisheries are regulated by a fixed daily catch limit since 2017 (i.e. bag-limit).
However, the level of these two management measures is controversially discussed. Stakeholders involved (i.e. managers, scientists, environmental organizations) or directly affected (i.e. commercial fishery, recreational fishery, tourism) have partially strongly divergent perceptions on the cause of the stock status and so of the appropriate measures which need to be taken in terms of stock recovery. This state of affairs continues to these days and has led to hardening fronts between these groups.
In order to investigate how these different perceptions are described and structured, we have collected and analyzed mental models of different stakeholders from 5 groups, i.e. commercial and recreational fisheries, NGOs, tourism, scientific experts and management agencies (Table S1).

Cognitive map elicitation protocol
We elicited stakeholders' mental models using a five-step protocol (see Schwermer et al. 2021 for more detail). First, participants were given a handout to prepare for the interview 1 week in advance (Step 1). To avoid misunderstanding, again the handout was explained in detail before stakeholders' mental models were created (Step 2). These steps were followed by an identification of the system components and their causal relationships by the participants (Step 3), from which they then drew a concept map representing their mental model following routine FCM data collection practices with open-ended concepts (Step 4). These maps were normalized and digitized after the interview and sent back to the interviewees for validation (Step 5). They then participated in an interview process where individuals were asked to identify relevant concepts (i.e., system components) and their causal relationships, from which they then drew a concept map representing their mental models about Western Baltic cod ecosystem and fisheries management (B). Participants' cognitive maps were digitized after the interview (i.e. maps were converted to digital weighted directed graphs using www.mentalmodeler.org) (C) and sent back to the interviewees for validation.
In order to evaluate the perception of the social-ecological system (SES) of the cod fishery in the western Baltic Sea from the perspective of different stakeholders, participants from 6 relevant groups were interviewed.

Managers
Officials focusing on i) catch quotas, ii) fisheries management at international and national level, and iii) nature conservation as well as iv) angling tourism at regional level 18.2

Rec Fish
Representative of the recreational fisheries at i) national and ii) state level and iii) with focus on sea angling 12.1 Scientists Academics with research focus on i) economy of commercial fisheries, ii) Baltic fish ecology, iii) Baltic fisheries management and iv) gear development in fisheries 18.2

Tourism
Members of tourism associations at regional level with focus on i) the promotion of regional angling tourism or ii) tourism activities in nature, as well as iii) manager of a fishing store 12.1