The smell of one's sweat can reveal if that person is genuinely happy or not, according to a new study.

Researchers at Utrecht University in the Netherlands found that positive emotions can be shared through the smell of our sweat. But that doesn't mean that you have to rub your sweat on someone just to prove that you're happy, because our bodies naturally release chemosignals, chemical compounds that people can smell.

To test if these "happy sweat" or emotional chemosignals can share the happiness to those exposed, the researchers collected sweat samples from the armpits of 12 male participants (smell donors). These volunteers neither smoke nor take any medications. They were also asked to avoid alcohol, sexual activity, smelly food or exercise during the study period. The males were shown videos to induce different emotions: fear, happiness and neutral. Afterwards, the sweat samples were exposed to 36 females (smell receivers) to determine if they can detect the happy sweat and whether it will make them happy as well.

Facial analysis showed that the females exposed to happy sweat smiled while those exposed to fear sweat frowned, suggesting that they were able to differentiate the happy sweat among three samples. There is also evidence that exposure to the happy sweat is contagious because the participants displayed a positive mood and better perception throughout the day.

"Our 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," Gün Semin, senior researcher and a psychological scientist at the Utrecht University in the Netherlands, said in a press release. "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."

The researchers believe that the findings of their study can be useful to the "odor industry" that might be interested in developing a "happy scent."

The study was published in the April 16 issue of the Association for Psychological Science.