The effects of social norms in sustainable advertisements on the levels of skepticism, perceived behavioral control, sustainability beliefs and purchase intention.

In recent times, sustainability has emerged as a critical concern, leading organizations to explore more environmentally friendly advertising strategies. Sustainable advertising seeks to encourage sustainable consumption. However, a significant gap exists between consumer purchasing intentions and preferences and actual behaviors. This has been extensively investigated in consumer behavior studies and concepts such as the Theory of Planned Behavior (TPB) have been presented to address this gap. This study investigates the interaction of factors within the TPB to determine whether there are additional relationships among these factors that might influence each other. To address this gap, this research focuses on examining the impact of incorporating social norms into sustainable advertising messages and assessing how different types of messaging influence the factors of the Theory of Planned Behavior, as well as other variables such as skepticism levels or sustainability beliefs in individuals. Thus, the research question proposed for this study is: To what extent do sustainable advertising messages that use social norms influence the skepticism, perceived behavioral control, sustainability beliefs and purchase intention of individuals. Moreover, this study also addresses the gap in literature regarding the individual impacts of descriptive and injunctive norms on behavior when presented in isolation. Thus, the main objective is to help marketing and advertising professionals to understand which factors lead to more effective sustainability advertising, promoting sustainable behaviors and attitudes among consumers and what type of messaging can be more effective to facilitate this objective. To address this research question, A quantitative experimental method was employed, utilizing an online survey for data collection. The participants were randomly assigned to each one of four conditions presented as an advertisement for a reusable bag from the brand IKEA in a between-subject method of testing. The conditions were manipulated so that each advertisement included a descriptive norm, an injunctive norm, a sustainability claim or the original advertisement without a social norm. This study, found no significant effects for the positive relation of advertisements using social norms and skepticism levels, perceived behavioral control or purchase intention. It did however find a significant effect in the influence of advertisements using injunctive norms and the equilibrium of the planet, part of sustainability beliefs. Thus, after addressing the limitations of this study, further research is needed to investigate the factors that lead to the consumers’ attitudes-behavior gap.