It’s a classic cop-drama trope. A bead of sweat drips down the brow of a suspect under questioning, the telltale sign of a lie about to be exposed. Perspiring betrays discomfort. Indeed, nothing says nervous like a shirt soaked-through with sweat. But even if you can keep the wetness under control—or at least under a couple layers of clothing—you may still be sending out a chemical distress signal that others can detect.MORE: Why Stress Sweat Smells So BadAn October 2013 study in the journal PLOS ONE found that when people give off the smell of sweat, it makes others question their confidence and abilities. In the experiment, participants were shown video clips of women doing “neutral” activities, such as doing work at the office, hanging out at home and taking care of their kids. Meanwhile, researchers pumped three types of sweat fumes into their noses: exercise sweat, stress sweat and stress sweat treated with Secret Clinical Strength. (The study was funded but not conducted by P&G Beauty, the makers of Secret antiperspirant.)The results stink. Even though the women in the videos didn’t show a hint of shine, both female and male observers rated them as more stressed when blasted with the smell of sweat without antiperspirant. And, the male observers who sniffed sweat also judged the women as less confident, less competent and less trustworthy.QUIZ: Are You Keeping Your Cool Under Pressure?The researchers believe that when the female observers smelled the sweat of other women under duress, they subconsciously identified with their sisters’ stress and therefore didn’t judge them harshly.