One of the main environmental policy challenges is convincing individuals and organisations to engage in socially desirable courses of action; that is, to have them internalise the consequences of their decisions. As contributions from institutional and behavioural economics have indicated, policies aimed at fostering pro-social action can be ineffective and even counterproductive if the interests and concerns of the relevant actors are not properly considered throughout the policy process. In fact, international conventions and national legislation around the world generally recommend stakeholder involvement in order to properly address pressing environmental challenges. The evidence that underpins and informs this recommendation, however, is still insufficient and scattered across different strands of literature. On the one hand, research on participatory governance has indeed systematically documented the potential for policymakers and resource managers to obtain high-quality, context-specific and legitimate input for environmental policymaking from participatory processes. On the other, the available research has also cast doubt on the potential of participatory processes to produce concrete change in (pro-social) action on the ground. In general, the success of these processes ultimately depends on their design, implementation and context. However, most of these conclusions stem from rich qualitative accounts of participatory processes, structured comparisons of cases and systematic reviews of case studies and the available literature. With this type of evidence, it is difficult to neatly identify the impact of participatory interventions on pro-social and cooperative behaviour and systematically assess the underlying mechanisms. This thesis addresses these knowledge gaps. The thesis investigates the extent to which and the mechanisms by which participatory interventions could foster (or hinder) pro-social and collective action for natural resource management and environmental protection. It comprises four chapters, each constituting a stand-alone, self-contained academic paper. Throughout the different chapters, the thesis reviews and integrates insights from the literature on participatory governance and from the institutional and behavioural analyses of pro-social and collective action. Furthermore, using two laboratory economic experiments (Chapters 3 and 4) and one framed lab-in-the-field experiment (Chapter 5), the thesis systematically assesses specific hypotheses concerning the potential impacts of participatory interventions on cooperative and pro-social behaviour and the underlying mechanisms of these impacts. The introductory chapter of the dissertation gathers, presents and discusses the insights gathered from each chapter. It expands on the motivations for the thesis, presents the general and specific research gaps and questions the thesis tackles and clarifies the conceptual, theoretical and methodological foundations upon which the thesis is grounded. Chapter 2 (entitled Participatory interventions for collective action in environmental and natural resource management) reviews the literature on participatory governance together with the literature on collective action in natural resource and environmental management. The main goal of this review is to contribute to integrating the main insights from both strands of literature regarding (a) the potential of participatory interventions to foster collective action and (b) the channels through which they might foment (or hinder) collective action. It therefore seeks to help integrate the insights from these different strands of literature, which, although related, have generally been disconnected until now. The chapter draws on the Institutional Analysis and Development (IAD) framework to organise these insights within a coherent conceptual framework. As the results of this literature review indicate, participatory interventions have the potential to foster collective action through two channels. Firstly, by helping resource users to change (and enhance) the rules, norms and strategies that constrain and guide their behaviour (the indirect channel) and, secondly, by directly influencing the specific behavioural factors (e.g. knowledge, trust, preferences, perceptions and beliefs) that collective action hinges upon (the direct channel). However, to sustain collective action, the relevant literature has consistently emphasised that trust needs to be continually cultivated and ensured. Therefore, in line with insights from earlier studies on participatory governance, the results of this literature review also indicate that practitioners and policymakers must not only design participatory interventions carefully to effectively build the trust needed to heighten and sustain collective action, but participatory interventions must also be adequately embedded within the broader (social-ecological and governance) context, providing for follow-up, enforcement, monitoring and conflict-resolution mechanisms. From Chapter 3 through Chapter 5, the thesis focuses on the direct channel, studying the potential of participatory interventions to directly influence behaviour within relevant economic action situations such as social dilemma and distributive action situations. Within a given environment and institutional context, the studies recreate processes commonly facilitated within participatory interventions. Chapter 3 assesses the effects of externally structured and facilitated processes of information exchange, and Chapters 4 and 5 examine the impact of inducing perspective-taking via role-switching techniques (Chapter 4) and instructions (Chapter 5). Thanks to this experimental approach, it is possible to systematically assess the behavioural impacts of these types of processes as well as the underlying mechanisms. Chapter 3 (entitled Structuring communication effectively for environmental cooperation) starts by reviewing previous experimental studies on the effects of two-way communication in social dilemmas to identify the elements that are commonly involved in effective communication processes. This review notes four cooperation-enhancing components of communication: (i) problem awareness, (ii) exploration of strategies to tackle the problem at hand, (iii) agreement on desirable joint strategies and (iv) ratification of agreed-upon strategies. A total of 560 students at Osnabrück University participated in a laboratory implementation of a voluntary contribution mechanism; a public goods game. The experiment implemented a series of interventions that represented these components of communication and contrasted the resulting levels of cooperation with the average outcomes of control groups interacting under either free (unstructured) communication or no communication whatsoever. The intervention that facilitated agreement on a common strategy (i.e. the combination of (ii) and (iii)) was particularly effective at boosting cooperation. Furthermore, combined with interventions promoting problem awareness and ratification, this intervention produced levels of cooperation similar to the average levels of cooperation observed in groups with free-form communication. The results of this experiment expand the understanding in the literature of the role of communication in social dilemmas and provide insights into the potential of structured and facilitated processes of information exchange and social interaction to foster collective action for environmental management. Chapter 4 (The effects of inducing perspective-taking through role reversal in a give-and-take a dictator game on pro-social behaviour) and Chapter 5 (Perspective-taking for pro-social behaviour in watershed management) deal with the effects of inducing perspective-taking on unilateral pro-social behaviour. The results outlined in Chapter 4 indicate that perspective-taking, induced through role reversal, can be associated with significant average changes in the participants’ self-reported state of emotions (in terms of both empathic and positive as well as in distressing and negative emotions). The emotional reactions that the role reversal seems to influence, however, do not appear to result in significantly more (or less) pro-social behaviour. The chapter explores and discusses two plausible explanations for these results, namely the transient effects of emotional reactions and the opposing effects of diverging emotional reactions on pro-social behaviour. These results come from the analysis of data from 144 students at Osnabrück University who participated as dictators in a laboratory implementation of a give-and-take dictator game. The design of the experiment allows the identification of the effect of inducing decision-makers to experience the other person’s position through unilateral role reversal on pro-social behaviour. During the simulation round, dictators in treatment groups experienced how it would feel to be in the role of the recipient. Dictators in the control groups only learned about the distributional consequences of their allocation decisions on recipients. Hence, through a treatment comparison, it was possible to single out the effects resulting from temporarily taking on the position of the other participant. To understand the underlying drivers of a potential behavioural change, the study elicited participants’ emotional states both before and after the simulation round. The results in Chapter 5 indicate that inducing perspective-taking can be associated with relatively greater pro-social behaviour based on an experimental study of downstream farmers’ behaviour in a watershed management context. Moreover, the provision of information on the social-ecological context during the perspective-taking exercise cannot account for the different behavioural patterns in the treatment and control groups. These results come from a lab-in-the-field experiment carried out with 177 downstream farmers in a Peruvian watershed. In the experiment, farmers in the treatment groups were motivated to imagine the upstream farmers’ perspective (i.e. to think about their thoughts and feelings) before deciding on whether or not to contribute to an initiative in the upper watershed. The initiative intends to help upstream farmers improve their well-being without compromising the water supply downstream. The behaviour of farmers in the treatment groups was compared against the behaviour of farmers in the control groups wherein perspective-taking was not induced. Taken together, the results of Chapter 4 and Chapter 5 illustrate the potential of inducing perspective-taking—commonly promoted in participatory processes—to trigger pro-social behaviour in economic situations. It can indeed alter relevant behavioural variables and trigger pro-social behaviour in distributive and social-dilemma situations. Nevertheless, as the literature on perspective-taking has previously indicated, the final effects depend on the specific procedures by which and the situations and contexts wherein perspective-taking is induced. Based on these findings, it is possible to sustain that participatory interventions do have the potential to effect changes in pro-social and cooperative behaviour at both the collective and individual level. Whether this impact is realised or hindered hinges on the procedures and contexts of participatory interventions. It would also depend on the mechanisms provided to follow up on the initiated processes and sustain and build upon the early outcomes. The contributions of this thesis are threefold. Firstly, it integrates insights from the literature on the institutional and behavioural analysis of pro-social and collective action and the literature on participatory governance for natural resource management. Secondly, it generates new evidence, based on experimental methods, in terms of the potential for participatory interventions to foster pro-social and collective action, and in terms of the mechanisms by which participatory methods and processes could effectively impact (or hinder) pro-social and cooperative behaviour. In this way, the thesis helps to bridge the gap of knowledge in terms of how participatory interventions can effectively change behaviour and, subsequently, encourage socially desirable social-ecological outcomes. In doing so, it also adds to the understanding of pro-social and cooperative human behaviour and the way that the processes of information-exchange and perspective-taking, which are often facilitated by participatory processes, may (or may not) advance it. Research on participation is, however, still ongoing and, in terms of the way forward, the thesis makes a third, methodological contribution. It demonstrates how experimental research in both the laboratory and in the field, conducted under a coherent conceptual and methodological framework, can complement one another and shed light on the extent to which and the means by which participatory interventions can produce changes in behaviour. The experimental method, in terms of both laboratory and field experiments, can therefore complement the set of methods traditionally employed to analyse participatory processes. The results of the studies comprising the thesis underscore the importance of carefully analysing the policy process. As contributions from the behavioural literature have repeatedly indicated, human behaviour is driven by a combination of self-regarding, social and procedural preferences. Hence, addressing pressing environmental challenges involving externalities and social dilemmas not only entails getting the policy design right to synergistically coordinate and orchestrate these different types of preferences. It also requires careful design, analysis and implementation of the activities and methods that structure and facilitate stakeholder interactions throughout the policy process.