Photo via flickr by mawel
“The smell of fear” turns out to have a foundation in science. All sweat smells—and some sweat screams anxiety to the world, according to a study published in June in PLoS One. “The chemical transfer of anxiety may cause a feeling of discomfort in the perceiver. It’s like a sixth sense,” says psychologist Bettina Pause of the University of Düsseldorf in Germany, one of the authors of the paper. Pause and her colleagues collected sweat from 49 students at two times—right before a university exam and during exercise. The researchers then had other students sniff the samples and scanned their brains with fMRI, which registers activity. Sniffers’ brains responded to sweat made during an anxious period differently from sweat produced through physical exertion. In humans, anxious sweat activates a cluster of brain areas known to be involved in empathy. “That suggests,” Pause says, “that anxiety—and maybe also other emotions—can be chemically transferred between people.”
In a conversation with Sputnik Observatory, Bettina Pause explains how our emotional state triggers the apocrine glands responsible for the body odor:
The skin is actually a supporting organ for microorganisms, for example. There are a lot of glands in the body which produce some chemicals which are odorless. And the odor has to be produced by the bacteria from these substances. And, of course, the skin gives the environment for the bacteria. And without bacteria, no body odor – and without skin, no body odor. There are glands, of course, across the whole body, but there are some so-called apocrine glands which are probably more responsible for the production of body odors, of the quality of body odors, than the so-called eccrine glands. The eccrine glands only produce water for your temperature balance. That you produce more water, if you’re hot.
The apocrine glands, there is a very complex mixture of substances from the apocrine glands, and people are still busy searching for very certain or special substances which might be responsible for the body odor. And this research is not really very successful. Where you have got the most successful results in human research is when you present the whole body odor mixture as a complex. Well, the apocrine glands, their production is dependent again on your emotional state. They are more productive if you are in an emotional arousing state and less productive when you just don’t care about the situation. The apocrine glands are, for example, strongly in the axillary area or also in the genital areas. And we think that important body odor signals are produced by the axillary glands.