Mouth expressions and movements can also be essential in reading body language. For example, chewing on the bottom lip may indicate that the individual is experiencing worry, fear, or insecurity.
Covering the mouth may be an effort to be polite if the person is yawning or coughing, but it may also be an attempt to cover up a frown of disapproval. Smiling is perhaps one of the greatest body language signals, but smiles can also be interpreted in many ways. A smile may be genuine, or it may be used to express false happiness, sarcasm, or even cynicism.
When evaluating body language, pay attention to the following mouth and lip signals:
Pursed lips might be an indicator of distaste, disapproval, or distrust.
People sometimes bite their lips when they are worried, anxious, or stressed.
Covering the mouth
When people want to hide an emotional reaction, they might cover their mouths in order to avoid displaying a smile or smirk.
Turned up or down
Slight changes in the mouth can also be subtle indicators of what a person is feeling. When the mouth is slightly turned up, it might mean that the person is feeling happy or optimistic. On the other hand, a slightly downturned mouth can be an indicator of sadness, disapproval, or even an outright grimace.