Caring for the Environment and Others: Investigating the Reciprocal Influence of Pro-Environmental and Prosocial Behaviors in Italian Young Adults through a Daily Diary Study

Introduction: Existing studies highlight a positive correlation between pro-environmental (PEB) and pro-social behavior (PB) at the between-person level, yet overlook their reciprocal relations. This study took a within-person perspective to explore their day-to-day relations and the moderating role of self-transcendence values in strengthening such associations.Method: We employed a daily diary design and recruited 60 Italian young adults (Mean Age = 25.8; SD = 3.6; Women = 58%) who reported their behavior once a day over 21 days.Results: Using Dynamic Structural Equation Modeling, we found no significant day-to-day spillover effect of PB and PEB. However, we identified significant same-day positive associations, namely, on days when individuals engaged in PB, they also showed higher than usual levels of PEB. Additionally, we found positive carryover effects in both PB and PEB, suggesting that young adults are likely to persist in their daily prosocial and pro-environmental efforts. No significant cross-level interaction between self-transcendence values and the spillover effect from PB to PEB was found.Conclusion: The findings provide new insights into young adults’ daily engagement in prosocial and pro-environmental behaviors, highlighting the role of day-to-day within-person changes, while accounting for stable, between-person differences in behavioral and motivational tendencies.Keywords: Pro-environmental behavior, Prosocial behavior; Young adults; Experience Sampling Methods; Spillover; Dynamic Structural Equation Modeling.