You've seen it when someone disagrees with you: a furrowed brow, tight lips, and raised chin. It's a face that means, basically, no—and it's actually universal. The same team of researchers that identified these 21 facial expressions say the "not face" is used so instinctively that it might as well be part of our language. Scientists at Ohio State thought humans might possess a single expression of disapproval—perhaps a combination of anger, disgust, and contempt—based on the idea that humans developed the ability to express danger or aggression before language, per a press release. So they put 158 native speakers of English, Spanish, Mandarin Chinese, and American Sign Language in front of a camera and asked them to recite negative sentences or answer questions about issues with which they were likely to disagree. Computer algorithms later searched the film for common facial expressions tied to their negative responses.
The "not face" appeared—combining the furrowed brows of anger, the raised chin of disgust, and the tight lips of contempt—at the same frequency as speech. "That is, we all instinctively make the 'not face' as if it were part of our spoken or signed language," the release explains. This implies that it's a facial grammatical marker, "a sound or facial expression or sign that has some grammatical function" and that differentiates "animal communication from human language," researcher Aleix Martinez tells the Washington Post. "To our knowledge, this is the first evidence that the facial expressions we use to communicate negative moral judgment have been compounded into a unique, universal part of language." An interesting tidbit: In some cases, ASL speakers made the "not face" rather than actually signing the word "not," which had never been documented before. "This facial expression not only exists, but in some instances, it is the only marker of negation in a signed sentence," says Martinez, whose research is published in Cognition. (Some facial expression are contagious.)