Norme personali e cooperazione condizionale nei comportamenti proambientali. Un confronto tra nudge sociali e morali

This article examines the effectiveness of norm nudges in promoting pro-environmental behavior, highlighting how cooperation is often conditional and sensitive to expected reciprocity, with the risk that, in contexts perceived as poorly cooperative, individual engagement may decrease rather than increase. Building on the distinction between social norms, based on empirical and normative expectations, and personal or moral norms, understood as internalized standards, we discuss why messages based on descriptive norms may be vulnerable, potentially generating boomerang effects when the prevailing norm is unfavorable. We therefore propose complementing interventions that act on expectations about others with interventions that activate internal motivations, making behavior relatively less dependent on the social context. To support this argument, we present an experimental case study developed at ISTC-CNR on waste sorting, comparing a social nudge with a moral nudge under conditions of low and high cooperation. Results indicate that, under low cooperation, the appeal to personal norms improves behavior relative to the social message, with a stronger effect among participants with stronger pro-environmental personal norms. These findings have implications for the design of behavioral public policy interventions, highlighting the need to diagnose the social context and segment the target audience when selecting the most appropriate normative intervention.