Sustainability going viral: pathogen avoidance as a barrier to second-hand consumption addressable by smell-based interventions

The fashion industry is a major environmental polluter, and behavioral scientists can investigate strategies to reduce obstacles to second-hand sustainable solutions. We propose an evolutionary framework rooted in the Parasite-Stress Theory of Values as a comprehensive explanation for the cultural, individual, and situational differences in second-hand clothing, postulating that second-hand clothing triggers evolved pathogen-avoidance mechanisms that form a barrier to second-hand purchases. This barrier can be mitigated by hygiene-related sensory cues, like a clean-laundry odor. In a field study (N = 257), we counterbalanced three odor conditions (clean-laundry, citrus, and regular store odor), and found that clean-laundry scent significantly boosted purchasing behavior by overriding the negative effect of germ-aversion. Indeed, among store’s customers, higher levels of pathogen avoidance resulted in less spending and more negative attitudes toward second-hand clothing. Further support for our mechanistic model is provided by the lab pilot study—where clean-laundry scent was shown to significantly reduce pathogen concerns, while enhancing garments’ perceived value and appeal—and by experimentally increasing pathogen saliency in survey responders, resulting in more negative second-hand clothing attitudes. This research highlights the critical role of pathogen avoidance mechanisms and cleanliness cues in overcoming psychological barriers to effectively promote sustainable consumer practices.