The impact of moral nudges on pro-environmental intentions and behaviour

This study aimed to test whether moral messages can improve pro-environmental intentions andbehaviour. According to two theoretical frameworks, the Moral Foundations Theory and the Theoryof Morality as Cooperation, sixteen moral nudges were developed based on distinct moralfoundations: Fairness, Authority, Loyalty, Heroism, Family, Reciprocity, Care and Purity. Eachnudge was framed either positively (encouraging moral actions) or negatively (discouraging immoralactions). Participants (N=2,713 Italians, representative with respect to age, gender, and geographicarea) read one moral message and then completed an adapted version of the Pro-EnvironmentalBehaviour Scale, which measures pro-environmental intentions for the next year. Additionally,participants were invited to donate some of their time to help create a flyer aimed at raising publicawareness on the climate crisis, providing a behavioural measure of pro-environmental engagement.Results showed that out of the 16 moral nudges, Authority in its negative frame increased proenvironmental behaviour, while Loyalty in its positive frame decreased pro-environmental intentions.Several nudges showed significant interactions with demographic variables such as politicalorientation, age, and gender. In fact, some nudges were effective only for right-leaning participantsbut had a backfire effect on left-leaning participants, and vice versa. Similar patterns emerged in ageand gender comparisons, with certain nudges influencing in opposite ways men and women, as wellas younger and older participants. These findings suggest that interventions using moral nudgesshould avoid a “one size fits all” approach and instead adopt more flexible and adaptive models thattake individual differences into account.