Doing good feels better: Moral appeals shape reward-related neural activity for pro-environmental gains.

To address societal challenges - such as combating climate change - people have to invest in collective goals rather than pursuing selfish objectives. However, prior neuroscientific research has often revealed that reward-motivation is enhanced for self-relevant gains. Here, we draw on social psychological research showing that people have a strong desire to be moral, to examine whether the motivation for investing effort toward collective goals can be increased by appealing to people's desire to be a morally responsible person. We conducted an ERP study examining how a moral appeal influences motivated performance and neural markers of reward processing. After reading either a moral or a non-moral appeal about one's responsibility toward climate action, participants (N = 70) completed a time estimation task where they could earn monetary rewards for themselves or a climate-friendly charity. We compared behavioral and ERP responses on self-gain, charity-gain, and no-gain trials between appeal conditions. Results showed significant interactions in both behavioral and ERP measures. Participants performed better on self- and charity-gain trials, compared to no-gain trials, following the moral appeal, whereas no trial-type differences emerged after the non-moral appeal. Confirmatory ERP analyses revealed no effects on the SPN or FRN. Exploratory analyses revealed enhanced Cue-P3, Feedback-P3, and LPP amplitudes for charity-gain trials following the moral appeal, while the CNV was more negative overall in the moral than non-moral appeal condition. In the non-moral appeal condition, Feedback-P3 and LPP amplitudes were more positive for self-gain than no-gain trials. These findings suggest that a moral appeal can enhance the reward value of pro-environmental outcomes and increase anticipatory preparation, potentially helping to promote positive behavior change.