Pro-Environmental Behavior Change Interventions: Experimental Evidence from Socially Responsible Investment and Pro-Biodiversity Behaviour

Human behaviour, both individual and collective, is the central underlying cause of the multiple environmental crises that we face today. More evidence on effective and scalable interventions to promote pro-environmental behaviour (PEB) is needed to bring about urgent transformative change. However, three central impeding developments can be observed in PEB intervention research: First, most studies on PEB interventions have focused on consumer behaviours and on climate impacts, with little attention given to other behaviours and environmental impacts. Second, research into the various PEB domains in different fields has mainly been conducted in isolation, with few attempts to connect these insights. Third, intervention research often treats audiences as homogeneous, focusing on main effects while rarely exploring how effectiveness varies depending on the target group.
This dissertation explores how connecting evidence across PEB domains can enhance understanding of behaviour change interventions. This question is examined by bringing together evidence from two contrasting domains that have received little attention in studies of interventions: socially responsible investment (SRI) and pro-biodiversity behaviour. Their distinctiveness makes these domains well-suited to demonstrating the wide variation of PEB. A specific intervention for behaviour change is conducted in each domain, and the results are brought together in this dissertation.
Article 1 comprises a narrative literature review to identify research gaps on SRI interventions and evaluate the potential for theory-informed transferability of interventions from the consumption to the investment domain. The outcome is a list of nine supported intervention strategies and 16 additional interventions that are potentially transferable to the investment context, which can be tested in future SRI research.
Article 2 is an empirical exploration of a specific research gap identified in Article 1. An experiment in the prosocial and sustainable consumption domains is conceptually replicated in the SRI domain. The study compares the effect of moral versus financial information framing under private or public visibility conditions. The results suggest that visibility moderates framing: moral framing leads to higher SRI under conditions of public visibility, but framing has no influence under private conditions. Therefore, the visibility effect identified in prosocial and sustainable consumption studies, in which financial framing was found to be more effective in private contexts and moral framing in public contexts, can be partially replicated in the SRI context for the public condition. A second experiment explores the effects of framing and visibility for different investor segments. Using latent class analysis, participants were grouped by values, SRI interest, financial literacy, and confidence. Three investor segments emerged, consistent with existing segmentation studies. The results show that the reactions in the three segments differ in terms of framing and visibility. For instance, a return-focused investor segment with low interest in SRI does not respond to framing or visibility.
Article 3 shifts the focus to the second domain of this dissertation: pro-biodiversity behaviour. Here, the impact of a large-scale behaviour change intervention implemented by the German newspaper Die Zeit is evaluated. The intervention aimed to promote insect-friendly attitudes and behaviours. The analysis incorporates pre-intervention levels of several insect-related outcome variables to determine the heterogeneity in intervention effectiveness across participants. The results suggest that the intervention successfully increased insect-friendly behaviour. However, insect-related attitudes, knowledge, and problem awareness improved only among those with lower pre-intervention levels. Individuals with higher pre-intervention levels demonstrated low potential for change in these outcomes.
The findings of the three articles contribute to PEB intervention research in several ways. First, the dissertation addresses two previously under-researched domains of PEB (SRI and pro-biodiversity behaviour), contributing to evidence-based intervention strategies in these fields (Articles 2 and 3). Second, by relating evidence from sustainable consumption and SRI through a narrative literature review (Article 1) and a conceptual replication of an intervention (Article 2), this dissertation illustrates how a theory-driven comparison of domains is a fruitful approach for PEB intervention research. Third, both empirical articles (Articles 2 and 3) examine the effectiveness of behaviour change interventions for different audience segments. Comparing the findings of the SRI intervention (Article 2) with those for the pro-biodiversity intervention (Article 3) suggests two factors that may influence the effectiveness of interventions for more environmentally engaged audiences: greater receptiveness to interventions (Article 2), and ‘ceiling effects’ due to limited upward potential (Article 3). Overall, this dissertation emphasises the importance of establishing stronger connections between evidence from different PEB research fields and domains, alongside domain- and audience-sensitive evidence. Bringing together disjointed insights from different domains may facilitate the translation of intervention research into practice, a necessary condition for broader implementation in support of transformative change.