Turning up the heat: Encouraging pro-environmental behaviour through Warm Glow

Behavioural nudges are now well established in public policy and are being increasingly used as environmental policy instruments [1]. However, they often fail to achieve persistent behaviour change [2]. Consequently, it has been suggested hat highlighting the intrinsic motivational basis of pro-environmental behaviour (PEB) may be a more effective strategy to promote and sustain behavioural change [3,4]. However, it remains unknown how to best leverage intrinsic motivation towards the environment [5]. In this research project, we propose that ‘warm glow’ can be used to leverage intrinsic motivation toward pro-environmental behaviours. According to Andreoni [6], the theory of ‘warm glow’ suggests that people act pro-socially because of the positive emotional reward obtained from doing so. In the environmental domain, warm glow has recently be identified as an important, yet under explored, intrinsic motive in environmental related decisions [7]. Recent field evidence suggests that directly appealing to warm glow motives has the potential to foster cooperation and increase pro-social behaviour in a variety of contexts [8,9]. However, it has not yet been explored whether warm glow experiences can be exogenously manipulated in a controlled experimental setting and whether they can create a positive feedback loop with PEB. In this study, we will use a large online experiment to study the effect of intrinsically (warm glow, cold prickle) and extrinsically (social norm) motivated treatment messages on pro-environmental behaviour, relative to a control group. The control message contains basic information about climate change. The warm glow message increases the salience of positive feelings from helping the environment and the cold-prickle message highlights the negative emotions associated with inaction. The social norm message presents an injunctive/prescriptive social norm. The exact research questions and hypotheses are outlined below. Moreover, we will explore the role of emotions as an underlying mechanism for the efficacy of information nudges in encouraging intrinsic motivation toward the environment. In contrast to previous research in lab settings that relies primarily on donation decisions to measure pro-environmental behaviour (e.g., dictator game with an environmental charity as the recipient), our study introduces a novel experimental measure of pro-environmental behaviour. We developed a pro-environmental behaviour task (adapted from the standard Stroop Task) in which participants can generate a donation for an environmental charity based on voluntary time investment and exerted effort. [1] F. Carlsson, C.A. Gravert, V. Kurz, O. Johansson-Stenman, Nudging as an Environmental Policy Instrument, Forthcom. Rev. Environ. Econ. Policy Abstr. (2020) 1–32. [2] E. Frey, T. Rogers, Persistence: How Treatment Effects Persist After Interventions Stop, Policy Insights from Behav. Brain Sci. 1 (2014) 172–179. [3] J.W. Bolderdijk, L. Steg, E.S. Geller, P.K. Lehman, T. Postmes, Comparing the effectiveness of monetary versus moral motives in environmental campaigning, Nat. Clim. Chang. 3 (2012) 413–416. [4] S. van der Linden, Warm glow is associated with low- but not high-cost sustainable behaviour, Nat. Sustain. 1 (2018) 28–30. [5] O. Kácha, K. Ruggeri, Nudging intrinsic motivation in environmental risk and social policy, J. Risk Res. 9877 (2018) 1–12. [6] J. Andreoni, Giving with Impure Altruism : Applications to Charity and Ricardian Equivalence, J. Polit. Econ. 97 (1989). [7] S. van der Linden, Intrinsic motivation and pro-environmental behaviour, Nat. Clim. Chang. 5 (2015) 612–613. [8] J.A. List, J.J. Murphy, M.K. Price, A.G. James, An experimental test of fundraising appeals targeting donor and recipient benefits, Nat. Hum. Behav. (2021). [9] M. Bergquist, L. Nyström, A. Nilsson, Feeling or following? A field-experiment comparing social norms-based and emotions-based motives encouraging pro-environmental donations, J. Consum. Behav. 19 (2020) 351–358.