PETA Vice President Colleen O’Brien said endangered chimps aren’t smiling but instead are displaying a “fear grimace,” and continued use of the image boosts the black market for them. To ...

But for a chimp, smiling is known as a “fear grimace,” which displays extreme distress and fear to other chimps. Chimps also yell, bite and fight as a way of solving disputes.

The chimp wasn’t laughing. Tina Deines. 17 Nov 2021 Global Great Apes. Comments Share article. ... “What people may think is a chimpanzee smiling is actually a fear grimace. ...

Given pictures of chimps' faces -- a 'play' face featuring a relaxed, open-mouthed expression, a fear grimace (bared teeth) or an alarm face (screaming) -- the chimps consistently matched negative ...

However, far more underlies this expression than fear. When a monkey is simply scared, such as when it spots a snake or predator, it freezes to avoid detection or else it runs away as fast as possible ...