You may not have to express if you are happy, as a new research claims that humans may be able to communicate positive emotions like happiness through the smell of their sweat.
Senior researcher on the study Gun Semin of Utrecht University in the Netherlands said that the study shows that being exposed to sweat produced under happiness induces a simulacrum of happiness in receivers, and induces a contagion of the emotional state.
This suggests that a happy person would infuse others in their vicinity with happiness.
To determine whether this emotional chemosignaling extends to positive emotions, Semin and colleagues examined whether sweat taken from people in a happy state would influence the behavior, perception, and emotional state of people exposed to the sweat.
The findings, the researchers say, suggest a 'behavioral synchronization' between the sender (the sweat donor) and receiver (the sweat smeller).
Additional data indicated that women exposed to happy sweat showed a more global focus in perceptual processing tasks, in line with previous research showing that participants induced to experience positive mood tended to show more global processing styles.
These findings, while preliminary, suggest that we communicate our positive and negative emotional states via distinct chemosignals, such that the receiver produces a simulacrum of the sender's emotional state. The researchers note that the fact that some measures indicated emotional contagion, while others did not, may highlight the difference between measures of emotion that draw on language versus those that don't.
The study is published in the journal Psychological Science.