At Utrecht University in the Netherlands, Gün Semin studies people sweating. Under different conditions of course, but sweating nevertheless.
Researchers recruited 12 Caucasian males to provide sweat samples for the study; each was exposed to clips meant to induce a different emotion while working out. The three were fear, happiness or neutral. 36 women were then recruited to smell the sweat samples (YUCK! For science!) of the three emotional states they were produced in.
When the women were exposed to sweat produced while watching clips that made the male recruit feel afraid, referred to as “fear sweat”, EMG electrodes showed that there was greater activity in the medial frontalis muscle, characteristic of the facial expression that indicates fear. Sweat produced while watching clips that made the male recruit feel happy caused the female recruit exposed to the sample to reflect this state and appear happier. Thus, the recipient of the happy sweat scent reflects the happy state of the male recruit. “This suggests that somebody who is happy will infuse others in their vicinity with happiness. In a way, happiness sweat is somewhat like smiling—it is infectious.”
Unfortunately, after smelling “happy sweat,” the women didn’t score as high for happiness on an emotion survey as the male recruits who produced the samples did. This suggests a better way to become happy is to have a workout than to go to the gym and sniff people who are having work outs.
Furthermore, if humans are so good at picking up on fear and happiness, the ability almost resembles an evolutionary advantage. For example, if someone ran past me and I could smell fear on them, It would be an advantage as I’d then be on the look out for whatever they’re running from and run myself.