In an era marked by escalating environmental crises, the urgent call to reduce plastic pollution has never been more pressing. Within this context, a recent study conducted by Canova, Bobbio, Benincà, and colleagues offers compelling insights into the psychological underpinnings of environmentally sustainable behaviors, specifically focusing on the use of refillable bottles among two distinct Italian populations: university students and non-student adults. Published in Humanities and Social Sciences Communications in 2025, their research harnesses the robust framework of the Theory of Planned Behavior (TPB) to dissect and predict the mechanisms driving this relatively understudied yet highly consequential habit.
The Theory of Planned Behavior has long served as a stalwart model within social psychology to elucidate the connections between individual attitudes, perceived control, social norms, and behavior. This framework posits that intention—a deliberate plan to act—is the immediate antecedent of behavior, itself influenced by attitudes toward the behavior, subjective norms, and perceived behavioral control (PBC). Canova et al. extend this conceptual model to examine the specific context of refillable bottle usage, aligning behavioral science with environmental objectives, particularly the Sustainable Development Goals aimed at curtailing plastic waste.
Delving into their methodology, the researchers conducted comparative surveys among Italian university students and a broader cohort of non-student adults, meticulously measuring core TPB components alongside additional psychological constructs such as self-identity. The inclusion of self-identity, a relatively novel extension, acknowledges that personal identification with behaviors can profoundly motivate consistent action, especially when tied to self-presentation and social signaling.
Their findings strikingly underscore that both attitudes and perceived behavioral control emerge as pivotal predictors of the intention to use refillable bottles. This suggests that individuals who not only positively evaluate refillable bottle use but also feel confident in their ability to perform the behavior are more likely to intend to adopt it. This dual influence reveals a nuanced interplay where cognitive evaluation and perceived facilitation jointly inform behavioral plans.
Moreover, intention, corroborated by past behavior, robustly predicts future usage of refillable bottles. The incorporation of past behavior into the model enriches predictive accuracy by recognizing habitual tendencies that can either reinforce or hinder new intentions. These results elegantly illustrate that behavior is not merely a function of attitudes and control perceptions but also deeply entrenched in history and experience.
An intriguing dimension is the differential relevance of self-identity across the studied groups. For non-student adults, self-identity exerts a more pronounced effect on intentions, suggesting that social and psychological dimensions linked to one’s identity and self-presentation strategies significantly motivate environmentally responsible behavior outside the university milieu. This insight posits that non-student adults may view refillable bottle use less as an abstract sustainability tactic, and more as an expression of personal values and social belonging.
The study also accentuates the broader implications of daily behaviors like refillable bottle usage within the context of global environmental sustainability. Given the staggering volumes of plastic production and its attendant pollution challenges, promoting such habitual actions offers a scalable and practical pathway toward mitigating environmental degradation. Yet, the authors lament the relative paucity of socio-psychological research in this domain, emphasizing a critical gap in understanding the precise motivators and barriers to plastic-reducing behaviors.
Furthermore, the research meticulously charts the conceptual pathways within the extended TPB model, illustrating how various psychological factors cascade to influence intentions and, subsequently, behavior. This refined perception equips policymakers and public health advocates with actionable knowledge to design interventions that resonate with individuals’ attitudes and empower their control perceptions.
For instance, educational campaigns could be tailored to improve positive attitudes toward refillable bottle use by highlighting environmental benefits and personal health advantages, while simultaneously removing logistical barriers that impede access or convenience—thereby enhancing perceived behavioral control. Leveraging social identity cues, especially among adults, might further amplify adoption by linking the behavior to desirable social groups or values.
In the context of university students, the comparatively lower significance of self-identity raises important questions about the relative weight of social norms and environmental awareness in shaping sustainable habits. Universities, as pivotal sites for socialization, may provide fertile ground for interventions that cultivate collective norms favoring environmental stewardship, thereby indirectly influencing intention and behavior.
Moreover, this research invites an interdisciplinary dialogue connecting social psychology, environmental science, and behavioral economics. Addressing plastic pollution necessitates an integrative approach whereby behavioral intentions are not only understood but actively harnessed to yield concrete changes in consumption patterns. The present study contributes a crucial psychological dimension to this multifaceted challenge.
Notably, the emphasis on refillable bottle use as a target behavior serves as a microcosm for broader sustainability initiatives. Plastic bottle consumption is emblematic of single-use culture, and understanding the psychological levers for switching to refillable options could inform efforts aimed at other single-use items, ranging from shopping bags to food packaging.
Beyond its empirical contributions, the study’s theoretical advances demonstrate the utility of expanding classic models like TPB with additional constructs such as self-identity and past behavior. This enhances the explanatory power of the framework and encourages researchers to adopt more holistic perspectives when investigating environmentally related behaviors.
Taken together, Canova and colleagues’ research embodies a vital step forward in unveiling the cognitive, social, and identity-based processes that sustain ecological habits. Their findings lay the groundwork for more tailored, psychologically grounded interventions that can be deployed across diverse population segments to foster a cultural shift toward sustainability.
As plastic pollution continues to choke ecosystems and imperil human health globally, insights gleaned from this study emphasize the power of everyday actions, such as opting for refillable bottles, to accumulate meaningful environmental benefits. It is a reminder that fine-grained understanding of behavior can fuel large-scale change principles essential for achieving the Sustainable Development Goals.
Future inquiries might delve deeper into the social normative influences that shape the behavior of university students and the contextual factors that impact perceived control across age groups. Additionally, longitudinal research could substantiate the causal links and temporal stability of intentions and behaviors, furnishing richer data on habit formation and maintenance.
In a world grappling with environmental urgency, bridging gaps between psychological theory and practical sustainability solutions is imperative. The extended TPB model applied by Canova et al. opens promising avenues for transforming individual intentions into collective environmental action, highlighting the profound potential embedded in ordinary daily choices.
Their research not only enriches academic discourse but also sends a clarion call to policymakers, educators, and consumers alike: by understanding and influencing the psychology of refillable bottle use, society can take a decisive step toward reducing plastic waste and protecting the planet for generations to come.
Subject of Research: The psychological determinants and predictive mechanisms underlying refillable bottle use among Italian university students and non-student adults, examined through an extended Theory of Planned Behavior framework.
Article Title: Use of refillable bottles by Italian students and non-student adults: testing an extended model of the theory of planned behavior.
Article References:
Canova, L., Bobbio, A., Benincà, A. et al. Use of refillable bottles by Italian students and non-student adults: testing an extended model of the theory of planned behavior. Humanit Soc Sci Commun 12, 1648 (2025). https://doi.org/10.1057/s41599-025-05962-x
Image Credits: AI Generated
