Researchers enrolled 12 healthy men, all of whom were free from any psychological disorder, nonsmokers, and that were free from any medications. They were then taken into the lab with washed and dried armpit; with absorbent pads to their armpits and were given pre-washed T-shirt to wear. They had them watch videos that were meant to induce several emotional states such as neutral, fear and happiness.
Next, in double-blind experiment, some women were recruited and asked to sniff the sweaty pad; while the researchers measured their facial expressions to determine the emotions they felt. Those who sniffed the happy sweat showed facial muscle activity associated with a Duchenne smile while women who sniffed the fear sweat gave signs of being anxious.
The researchers then concluded that, it is a form of chemical signaling, through which emotion and intention could be communicated to others.
