Motivating Sustainable Lifestyles: The Role of Anticipated Emotions and Psychological Reactance in Mobile App‐Based Interventions

ABSTRACT Behavioural interventions using smartphones are increasing, yet limited research has examined the psychological drivers and barriers to adopting sustainable behaviours through mobile app‐mediated interventions. This study investigates how anticipated emotions and psychological reactance, in tandem with the Theory of Planned Behaviour (TPB) constructs, shape individuals' willingness to accept sustainable lifestyle practices (‘Challenges’) delivered through a mobile app. A total of 1,333 adults in the United Kingdom were presented with sustainable lifestyle Challenges and surveyed on their perceptions and acceptance. Multilevel modelling revealed that anticipated emotions, such as feeling inspired, happy, and guilty, positively predicted Challenge acceptance, while psychological reactance emerged as the strongest negative predictor. Factors composing the TPB constructs—attitudes, subjective norms, and perceived behavioural control—also showed effectiveness consistent with prior research. Exploratory analyses further highlighted that prior experience with sustainable practices moderated some of these relationships, revealing nuanced effects. These findings extend the TPB framework by incorporating affective and autonomy‐related constructs, enhancing its explanatory power for predicting pro‐environmental intentions. Practical implications for designing user‐centered mobile interventions to foster sustainable behaviour adoption are discussed, with a focus on balancing emotional engagement and autonomy to maximise impact.