It felt pretty silly to do, but they explained that a human smile is seen as a threatening expression to chimpanzees. When they are afraid or when they are trying to be intimidating, they will show all their top teeth and do what we call a “fear grimace.”
“If you smile at a rhesus monkey it may interpret your show of teeth as an aggressive gesture and respond violently.”
Interpreting a Chimp Smile
Surprisingly, chimpanzee smiles signify fear. When chimps bare both their top and bottom teeth, though it may look like a goofy grin, scientists have come to understand this expression as a “fear grimace.” Chimps make this face when they're afraid, anxious, or uncertain.
Although smiling is often associated with submissive or non-aggressive behavior in gorillas, eye contact is a practice that is discouraged by primatologists, as apes are likely to interpret eye contact as a challenge or a form of aggressive display.
So if they had had little contact with you in particular, or with humans in general, your smile might get an aggressive response—most likely a very toothy “smile.” But the great apes are very much like us, and quite intelligent. They soon learn to “read” the faces of humans with whom they have a lot of interaction.
Please just don't smile at a gorilla or chimpanzee. Even though gorillas and chimpanzees are also primates, they perceive smiles or showing teeth as being acts of intimidation or as a threat.
It's almost an involuntary response. Dogs, too, respond to human smiles with a complex neurological process. But, in short, when you smile at your dog, he recognizes your emotion, empathizes with your happiness, and responds to you with expressions of happiness.
Think of it as riding a bus with strangers – it would be creepy to stare down someone you don't know, but making eye contact and acknowledging someone else's gaze is perfectly fine and, in fact, the polite thing to do.” Interestingly, chimpanzees vary in how much eye contact they choose to make with us.
In most primates, eye contact is an implicit signal of threat, and often connotes social status and imminent physical aggression. However, in humans and some of the gregarious nonhuman primates, eye contact is tolerated more and may be used to communicate other emotional and mental states.
To diffuse the situation, don't make eye contact or smile with your teeth showing—in the nonhuman primate world, these are almost always signs of aggression. Monkey attacks are extremely rare in the wild; the creatures tend to be scared of us and often scamper away when a person gets within 100 feet.
It is easy to tell when a chimp gets mad: they become aroused and perform conspicuous displays and noisy tantrums. The researchers found that the chimpanzees were more likely to collapse the table when they were aroused than when they were calm.
The main reason chimps spit water is to get a reaction from someone or for attention. This behavior is completely friendly and playful. Sometimes, it can be seen as validation! Beverly, a caregiver aide, mentioned when she got water spit on her by Quintin.
Ultimately, this comes down to respecting other people's privacy and personal space. Telling someone to smile has much greater potential to harm or alarm than it does to actually make someone feel good about themselves. So mind your own business.
In addition to the functions of aggression in hostile scenarios, researchers have noted that relaxed open-mouth displays in normal, calm or post-conflict periods are crucial in many primate species for submission, reconciliation and reassurance to coordinate social interactions, increase social tolerance and maintain ...
To mountain gorillas, any person who keeps direct eye contact with them is a challenger and an enemy who comes to destroy the family. Direct eye contact will therefore force the silverback to charge and fight you in order to defend his family. If you want to be peaceful with gorillas, you should avoid eye contact.
If you encounter an aggressive lion, stare him down. But not a leopard; avoid his gaze at all costs. In both cases, back away slowly; don't run.
Monkeys have tear ducts, but these are just to keep the eye from drying out; weeping and shedding tears is not a behavior monkeys perform when sad. However, monkeys are very social creatures and do have vocalizations and facial expressions of their own to express sadness and anguish to each other.
An unarmed human could not beat a chimpanzee in a fight.
At some point, the chimp is going to respond to any harm being done to it, and it will use vicious attacks to kill the person or render them unable to fight. Chimps maul their prey and enemies, and they would do the same to humans.
Among primates, eye contact is seen as especially aggressive, and staring at them in a zoo can induce agitated behavior. Chimpanzees use eye contact to signal aggression in hostile encounters.
When it comes to simple strategy games, chimpanzees consistently outperform humans at tasks that involve short-term memory and predicting opponents' moves.
Often the submissive grin invites interaction from others, but it's also possible that your dog is trying to increase distance between herself and others if she feels threatened. It's likely that your dog has continued “smiling” at you and your family because it's gotten her a lot of attention in the past.
Aussies are known to bare teeth when they smile, one of only a few breeds to do so. Although they are not obsessive barkers, they will bark to protect their property, and warn you of nearby activity.
But it is unmistakeably doggy. Canines don't sweat from skin pores like humans do, but they do perspire from their paws and hair follicles. They also produce oils that are essential for their skin and hair. Then there are the glands in their ears, which release a lightly yeasty scent.