Environmental psychologists are investigating whether olfactory stimuli can reduce interpersonal tension in high-stress public transit environments. They design a study to test whether dispersing a subtle peppermint essential oil mist at a busy underground subway customer service kiosk reduces the frequency of confrontational or uncooperative interactions with commuters compared to a control condition with no scent. The scent is alternated daily over a two-week period, and trained staff (unaware of the daily condition) record the proportion of commuter interactions categorized as "highly confrontational" using a standardized behavioral checklist.