So sweat stress largely comes from your apocrine glands—but why are those glands the ones that produce scent? Well, it’s all evolutionary: “Adrenaline stimulates apocrine glands to secrete their complex and thick secretions,” says Bailey, which then drench your armpits in “chemosignaling information that’s hard to mask.” Meaning, other humans can perceive your fear or stress sweat, and this signals to them that there may be a threat ahead.
In fact, research shows other people can become fearful themselves5 after smelling your fear sweat—so in a way, you’re sending signals to protect others around you from danger. Obviously, public speaking jitters or anxious social situations aren’t really a threat to other folks, but our bodies are essentially communicating with each other in a transparent (albeit smelly) way.
What’s more, “Studies have shown that fear sweat is not easy to mask with fragrance6,” says Bailey, which is understandably frustrating when you’re trying to find a deodorant that, uh, works. “Other indicators of stress, such as facial expression, can be manipulated and controlled, but fear sweat can’t,” she adds. That, too, might be evolutionary, as you’re able to tell when another person is lying about a certain risk.
