Pheremones, Man
Researchers recruited 10 men and taped absorbent pads under their armpits while they watched 25-minute videos taken from The Shining and Jackass, on separate occasions.
When the women, who had not been told where the samples came from, were exposed to “fear” [Shining] sweat they opened their eyes more widely – an expression of fear. In contrast, the “disgust” [Jackass] condition prompted them to adopt a corresponding facial expression by lowering their eyebrows and wrinkling their noses.
The effects also applied to “sensory acquisition” behaviour, which naturally occurs when we are afraid but is suppressed when we are disgusted. In the “fear” condition women sniffed more deeply and scanned the room with their eyes more – an evolutionary response designed to help to detect danger. The “disgust” scent had the opposite effect, causing the women to wrinkle their noses and lower their eyebrows, which in nature would help limit exposure to noxious chemicals.
The two fear/disgust tells (you can predict how the woman behaves by knowing the movie the men watched) admit alternate explanations than the women actually feeling any emotion as though they had been watching the respective movies (in fact, they don’t volunteer experiencing any particular emotional reaction), but I’m as convinced as I’ll ever be by a single N=10 study.