Human Sign and Body Language - a Mirror of Animal Behavior
Smiles and Hands as Used by Humans and Apes
Humans and apes alike belong to the species of primates and have a very similar genetic make up. Therefore it is not surprising to learn that both have a variety of body language expressions in common. Unlike other animals, apes have hands and are capable of making gestures to communicate with each other. Apes are also able to learn signals and to be trained. In this case, the imitation process is reversed. Whereas human body language may imitate ape behavior, it's also true that humans can teach apes to 'ape' human gestures.
The Three Apes
For more in depth information about ape body language consult: Ape Gestures and Language by Amy S. Pollick and Frans B.M. de Waal of Atlanta University. The study focuses on how human language may have its origin in animal body language rather than in verbal signals, but it contains a lot of gesture explanations.
An international gesture in human body language is that of beggars, who sit or stand with their arm outstretched, open palm up, asking for money or food. Apes are prone to make a lot of hand and body gestures. An ape which stretches out its open palm is either also asking for food or signaling an invitation for sex to the opposite sex.
An outstretched hand in a human, often as preliminary to a hand shake, signals openness and friendliness. An ape doing the same will make a peace offer or just signal that it is not aggressive.
Humans automatically raise their hands and cover their ears to indicate too much noise or that they don't want to hear any more of what's said to them or what's going on around them. Apes do exactly the same.
When apes gesture, they use their right hand. It's controlled by the left side of the brain, which in humans, is the location of the nerve center for language. It would be interesting to find out if there are left handed apes where the brain functions would be reversed.
Apes have a vivid facility for facial expressions. For most other animals, showing their teeth is a gesture of aggression. Not so for apes. Like humans, apes can smile. It's a sign of submission, of wanting to be friendly and non-threatening. Apes also can emit a lopsided smirk by pulling up only one side of the mouth. Just as in humans a smirk indicates insolence and arrogance.
Flared nostrils express dissatisfaction. Humans take in a deep breath, their nostrils extend and they indicate by the gesture : I've had enough.' Apes do the same. Flared nostrils in an ape indicate that they are about to attack.
Humans express a wide range of emotions with their eyes. Sadness, joy and fear are shown by opening eyes wide, narrowing them or half closing them. Apes have huge eyes and just like humans, are able to express their feelings and emotions through them. Like no other animal, apes are even able to roll their eyes.
Cockiness and Anger in Humans and Cats
Felines do not emit as refined signals as apes and of course they can't make gestures, because they have no hands. However, there are some body language characteristics observed in humans which can also be seen in cats . Most notably are the expressions of cockiness and anger.
Humans express self satisfaction, pride or cockiness by walking very erect and throwing their head back and thrusting the chin forward. The equivalent behavior, typical to cats, is the stalking or prancing around, head up and tail in the air.
When humans are shocked or extremely frightened, the hair on their arms and sometimes their neck literally stands on end. The same applies to felines. Adrenaline rush causes the phenomenon. Raised hackles in humans as well as in cats signify fear, imminent aggression or shock. The same applies to dilated pupils. The human eye tends to expand involuntarily in extreme situations just as it does in cats.
Fake Smile and Grovelling in Humans and Dogs
Take a look at the fake smile in humans. The teeth are bared with the lips stretched as far as they will go, but the smile does not reach the eyes. As opposed to apes, dogs signal aggression when they bare their teeth. The interpretation covers impatience, aggression and defense. Dogs showing their teeth and even emitting a growl at the same time, are about to attack. Grinding the teeth, audibly or not, means the same. Dogs move their mandibles and sometimes salivate in the same way.
Dogs show submission by turning on their back and throwing the paws up in the air. Although human body language does not go to that extreme, the equivalent is raising and opening both arms, often accompanied by a shrug.
Humans show humbleness or a plea for forgiveness by grovelling. The other person is approached with the head bowed and the feet shuffling. Who hasn't seen a grovelling dog? Belly on the ground, head lowered, paws humbly creeping forward. Humans do walk upright, so there is no belly creeping, but otherwise their body language in the same situation mirror's dog-behavior.
On the whole it's quite amazing how much human body language resembles in many ways the means of non verbal communication of animals.