What use is the fear grin in nature? i know chimps and mokeys do it alot, i found myself doing it once?

Question

when i was watchign a movie last night, i did the fear grin like automatically

what use is it?

i read something once where people were documenting chimps and one chimp held its mouth to stop itself from looking scared of its rival.

Answer 1

What is a fear grin?  Yes, define a fear grin.  And your definition will be different than mine and many others.  What makes you assume that chimps can make a fear grin?

The expression we see on an animals face has nothing to do with that animals emotional status.  Humans read in to an animals face what they think they see.  A hyena does NOT laugh or smile.  That's just the sound they make and the way they make it.  Animals are not humans wearing fur, feathers or scales.

Answer 2

In context, it looks like a motion indication submissiveness, if not fear.  When a chimp is behaving aggressively, it displays the top teeth (including prominent canines, which are more used for eating coarse vegetable material, than in conflict.) When the lower teeth are displayed, you get a "fear grin". The expression "sheepish grin" describes this expression in people.

I'd like to speculate that the chimp holding its mouth was doing the same kind of thing that people do when they wear sunglasses to conceal the expression displayed by the eyes.

One of Darwin's most interesting books is a study of expression in people and animals.

Jim, if you were to spend even a few days in the company of a dog, (Cartesian dichotomies notwithstanding!) it would be obvious to you that an animal experiences and displays emotion. If one investigates the behaviour of Bonobo ("pygmy") chimpanzees, it is clear that their behaviour shows a level of social organization that integrates conflict and other emotions at least as well as "Homo sapiens sapiens" - maybe better.

Covering the mouth is an almost universally polite act. The "American" smile, displaying as many teeth as possible, is almost unknown in non-Western art, and in Western art before the eighteenth century.  Bearded faces, with many teeth showing is the way the barbarian Westerners were portrayed in Japanese art. In other contexts, an open-mouthed smile was used to depict stupidity or insanity.

Answer 3

Chimps are like people. They can smile, but the fear grin is an aggressive display of teeth. Chimps will hide an involuntary display because they don't want to appear aggressive. That would be a good way to get beat up or killed by bigger, meaner chimps.