Chemical Communication by Humans: Beyond Pheromones
The concept of being able to communicate emotions & conditions through body smell signals (i.e. signals of a chemical nature, same as other animals), has been at the bottom of lots of research into how humans interact. Pheromones haven't been proven to be a conclusive given yet (though theories abound), but other signals seem to have been at the focus of new research.
"To find out, researchers had male subjects watch two movies. One was scary, and the other made viewers feel disgusted. The researchers then collected the participants’ sweat. Female subjects then smelled the sweat, while the scientists recorded their facial expressions. And the women who smelled “fear sweat” actually produced fearful facial expressions. While those who smelled the “disgust sweat” made disgusted faces. The inference is that the chemical compounds impelled the female subjects to remotely experience the same emotions felt by the sweaty males. The study is in the journal Psychological Science." [Jasper H. B. de Groot et al, Chemosignals Communicate Human Emotions]