A study by psychologists Matteo Perini and Jasper de Groot from Radboud University found that the smell of fresh laundry in a secondhand store can encourage people to spend more than other scents, such as citrus or the usual smell of used clothing. The research, published in the journal Evolution and Human Behavior, suggests that this effect may be related to how humans naturally try to avoid germs and disease. To test their hypothesis, the researchers placed scent diffusers in a secondhand store, releasing different scents on different days. One day, the store had a citrus scent; another day, it had the smell of fresh laundry; and on a third day, no scent was used. They found that the fresh laundry scent led to increased spending, especially among people who were more concerned about germs, as measured by a contamination fear scale. In a follow-up lab experiment, participants who were exposed to the scent of fresh laundry were more likely to believe that secondhand clothes were worth more and less likely to think they were unclean. According to de Groot, the fresh laundry scent helps reduce people's perception of potential contamination. This finding shows how scents can influence real-world behaviors, especially in the context of sustainable choices like buying secondhand items. The study, titled "Sustainability going viral: pathogen avoidance as a barrier to second-hand consumption addressable by smell-based interventions," highlights the potential of using scent to encourage more environmentally friendly behaviors. It suggests that simple sensory cues can help overcome psychological barriers to adopting sustainable habits.