When scared, many animals release chemicals as a red flag to alert members of the same species. Psychologist Denis Chen, from Rice University, says that humans also communicate chemically through sweat .
To prove it, Chen collected several samples of "scary sweat" collected from the armpits of male volunteers while watching horror movies. Next, a group of women were asked to look at a series of images of human faces, some with expressions of happiness and others of fear, while smelling the sweat of their companions. The experiment revealed that when facial expression was ambiguous, the chemicals in sweat made women choose to identify them as the result of fear. "Our results reveal that human sweat contains an emotional message, " says Chen, who has published his findings in the journal Psychological Science .
Smell is a prevalent form of social communication in animals, but its role in humans is unclear. If we have developed such acute senses of sight and hearing, why do we still need smell? According to Chen, what happens is that "smell guides our social perception when other dominant senses are weakened."
