The Mouth

Facts About the Human Mouth

The mouth is a very active part of the face. Either deliberately or spontaneously, it conveys varied meanings of nonverbal messages depending on its position or movement. The mouth, when it is raised up, readily communicates positive feelings, happiness, and optimism. However, when it is kept straight, it conceals emotions; and when it is turned down, it expresses sadness, confusion, and dissatisfaction.

A person ‘pulls a long face’ by deliberately lowering the corners of the mouth to indicate something negative; this will generally be accompanied by a shaking of the head.

The mouth faithfully reflects the consensus of our thoughts and our smiles or grimaces. It is one of the most noticeable parts of the face. It gives automatic expression to deeper and more important aspects of our nature.

The mouth, when relaxed, tells a great deal about the person. A person may also tense his mouth by tightening and pressing together the lip and jaw muscles, to express anger, frustration, determination, sympathy, threat, or pensiveness. ‘A tense mouth precisely marks the onset of a mood shift, novel thought, or sudden change of heart’ (Givens, 1999).

Functions of the Mouth

There are multiple ways by which the human mouth functions, as the following headings show:

  1. Speaking
    The mouth, when speaking, sends several signals.
  2. Mumbling
    If the mouth moves little, perhaps including incoherent mumbling, this may indicate an unwillingness to speak, for example, from shyness or from a fear of betraying themselves.
  3. Incessant talking
    A mouth that moves a lot during speech can indicate excitement or dominance as it sends clear signals that ‘I am speaking, do not interrupt!’
  4. Articulation
    Careful shaping of words can also indicate a person with auditory preferences or a concern for precision and neatness.
  5. Talking fast
    Fast speakers are often visual thinkers who are trying to get out what they are seeing. They may also be looking upwards.
  6. Talking slow
    Slow speakers may be deep thinkers who are being careful about finding the right words. They may also have an auditory preference as they carefully enunciate each word.
  7. Eating
    The mouth is used for eating, and the way people eat can reveal things about them.
  8. Opening
    Good manners demand that a person opens his mouth to the minimum while eating, taking in a moderate amount of food. The mouth is kept closed while masticating or chewing what is in it. During this time, one is refrained from speaking with his mouth full. An ill-mannered person gobbles large mouthfuls and keeps the mouth open while eating. In the same token, burping is acceptable.

    In some cultures, people consider it a normal practice to make sounds with the food in their mouths to express that they are relishing their morsel. At times the host may even expect the guest to make such noises to rest assured that the food is acceptable and appreciated. Some people eat slowly because their minds are also occupied at the same time chewing on ideas. Such people also tend to slide their jaw sideways when they eat.
  9. Drinking
    As with eating, so with drinking. The proper manner for drinking is to slip small amounts and swallow noiselessly. However, people do drink with loud glugging and gulping, and burp, all of which may appear distasteful or acceptable depending on the culture. Generally, one must raise the glass or cup to the lip rather than lower the head while drinking.

Breathing, another important function of the mouth, consists in the following:

  1. Sigh
    A short, deep, exhaling sigh can indicate sadness, frustration, or boredom.
  2. Sob
    Short inhalation, particularly in a sequence, can be like silent sobs and hence be an indicator of deep and suppressed sadness.
  3. Panting
    A person who is frightened or angry by the fight or flight reaction may well open his/her mouth to get more oxygen in preparation for combat or running away. This may also involve breathing faster (panting).

Parts of the Mouth

A.  Teeth
There is not much to say about the nonverbal communication of the teeth. Following are some observations:

  1. Biting
    Baring the teeth in a snarl may appear as a threat to bite an opponent, though actual biting is rarely done. Gently biting another person’s lip or ear can be a sign of affection.
  2. Smiling
    Exposing the teeth in smiling tends to indicate extreme pleasure. People who are self-conscious, particularly if their teeth are not that attractive may try not to show their teeth when smiling.
  3. Sound
    Chattering teeth may indicate extreme fear and is usually accompanied by shaking of the body. This may also indicate extreme coldness. Grinding teeth can indicate suppressed anger or frustration as the person tensely tries not to speak. Light tapping of the teeth can be mild frustration or thinking (it is similar in effect to tapping of a finger). As with other repetitive action, teeth noise can also just be habit.
  4. Tapping
    Sometimes people tap their teeth with their nails, making a noise that echoes in the mouth. This can signal thinking or boredom. It may also be a deliberate interruption or irritant, although this is less likely.

B.  Tongue
The tongue is related to the spoken language. However, it can also send some important nonverbal signals when it performs the following functions:

  1. Sticking out
    Sticking out ones tongue at someone is the momentary visible protrusion and retraction of the tongue between the lips. It is generally an impolite gesture. It is a rather childish gesture and thus reflects negatively on the one doing it. A haughty person may deliberately stick his tongue out in an amusingly cheeky way. This will be accompanied by an intense face and often followed by a smile or laughter. A person who is straining while doing a job may also stick out his tongue; it will usually be seen sticking out the side of the mouth. The tongue just slightly protruding from the mouth may indicate that the person does not want to interrupt others.


    Tongue showing is a universal symbol to express ‘disagreement, disbelief, disliking, displeasure, or uncertainty. It may modify, counteract, or contradict verbal remarks’ (Givens, 1999). When a person says he agrees, yet shows his tongue, it in fact suggests that he is not in agreement. During conversation, when someone protrudes and retracts his tongue while listening, the speaker may read it as a cue for lack of clarity, or a pending issue, and would do well to probe so as to help the listener verbalize his thoughts or mood.

    A related gesture is the tongue just slightly protruding from the lips for a while. Studies show that a listener in the posture is less likely to be interrupted. In one situation, a salesman at a large store whose tongue was not visible was preferred by customers over another whose tongue was showing (Givens, 1999).
  2. Licking
    The tongue licks the lips at the sight of food the person relishes or another person who is desirable.
  3. Biting
    The biting of the tongue typically indicates that the biter wants to say something but he somehow feels unable or unwilling to say it. He is perhaps afraid of offending or of breaking social rules.
  4. Hidden
    With mouth closed and tongue inside the mouth, the movements of the tongue can sometimes be detected. Pressed against the cheek, it can indicate thinking and uncertainty. Pushed in front of the teeth, or pushing out the lips, can also indicate uncertainty.