General theory of pro-environmental behavior spillover

Widespread adoption of a sustainable behavioral pattern encompassing many different areas of consumption and daily life (e.g., food, transportation, and energy use) is crucial for addressing pressing environmental challenges like climate change, biodiversity loss, resource depletion, and pollution. This means that existing theories mainly focusing on isolated behaviors and consumption choices need to be augmented by research explicitly modeling the psychological links between the different behaviors and decisions. This project seeks to improve our understanding of the links between different pro-environmental behaviors by examining the various conditions under which one behavior affects the likelihood of future performance of other behaviors by the same actor (which is referred to as behavioral “spillover”). This is still an unresolved problem in research on pro-environmental behavior and sustainable consumption, with only partial answers provided in the fragmented literature. More specifically, the project addresses the need for a comprehensive understanding of the complex psychological mechanisms behind pro-environmental behavior spillover. To this end, we will conduct a series of close-knit surveys and experiments concurrently examining a large number of factors relevant for spillover. This will make it possible to derive the first comprehensive, yet parsimonious, theory of pro-environmental behavior spillover. Thus, on the one hand, our work aims to unify the field of pro-environmental behavior spillover research and to provide a new, empirically sound basis for further advancements in this area. On the other hand, our approach also promises to inform policy making, in particular the design of impactful and cost-effective interventions designed to foster the adoption of a wide range of pro-environmental behaviors.

A new theory of pro-environmental behavior spillover addressing key limitations of previous theoretical models is developed and tested with data from nearly 10,000 participants from six countries. Where previous research in environmental psychology examined no more than two or three possible psychological mechanisms mediating spillover at a time, we concurrently test up to seven of these mechanisms, making it possible to account for interlinkages between various mediating factors. Changes in environmental concern, worry about climate change, and environmental self-identity mediate spillover most consistently. Spillover processes are largely similar across individuals with varying attitudes towards the environment. We conclude that a relatively parsimonious theory appears capable of explaining pro-environmental behavior spillover. The new theory helps both unify previous work in the area and provides a basis for further theoretical refinement. In particular, the theory is easily amenable to incorporating and testing additional factors that may influence spillover and as such provides an excellent platform for cumulative progress in this area. We additionally introduce a novel approach based on methods from the choice modelling literature to explore spillovers across preferences in the context of climate change mitigation behaviors, travel mode choice, and eco-shopping. These advances contribute to a better theoretical understanding of environmental behavior, its motivations, and environmental behavior spillover. From an applied perspective, our results suggest that attitudinal variables are unlikely to significantly affect downstream impacts of behavioral policy interventions. We, however, also show that interventions based on social norms, defaults, and commitment may be relatively ineffective in encouraging behavioral change, which can inform the selection of policy tools meant to foster environmental sustainability in today’s societies. Data collected as part of the project also provides important insights beyond the topic of spillover. In particular, the data was used to generate evidence on how personal and social norms interact in motivating pro-environmental behavior and on motivations for consumer adoption of sustainability mobile phone apps.

Psychology and other disciplines have made great progress in finding determinants of single pro-environmental behaviors in recent years. However, for challenges like global climate change, biodiversity loss and resource depletion, it is not sufficient to address single behaviors, but it is necessary to understand the links between a complex set of behaviors all affecting the problem. Our project therefore focuses on conditions under which one pro-environmental behavior increases the likelihood of other pro-environmental behaviors by the same actor (positive spillover) and under which it reduces the likelihood (negative spillover or psychological rebound effect). This is still an unresolved problem in environmental behavior research, with only partial answers provided in the fragmented literature. This project, specifically, addresses the urgent need for a comprehensive understanding of the complex mechanisms behind pro-environmental behavior spillover. This in turn requires methodologically demanding basic psychological research to develop an innovative, integrative theoretical model. To this end, we will conduct a series of close-knit surveys and experiments concurrently examining a large number of potentially relevant factors relevant for spillover, something that has never been done before. This will make it possible to determine the unique contribution of individual factors and, consequently, to formulate a comprehensive yet concise theory of pro-environmental behavior spillover. Our work will unify the field of pro-environmental behavior spillover research and provide an empirically sound basis for further advancements in this key area. Our approach will also inform policy, in particular the design of impactful and cost-effective interventions designed to foster the adoption of a wide range of sustainable behaviors. Due to its comprehensive nature and methodological rigor, the project promises to provide firmly empirically established policy recommendations.