You’re scared
Well… “I can smell your fear” is a true sentence. A U.S. military experiment suggests that people can literally smell fear. For the study, researchers collected sweat samples from 20 novice skydivers before and during their first tandem jump, and then again as they ran on a treadmill for a similar duration of time. Volunteers in brain scanners were asked to take a whiff of each sample. The brain regions associated with fear were more active when the volunteers sniffed the skydiving sample than the treadmill sample.