The limbic system controls the lips, which are nerve-rich and vascular. They become rough as a result of stress and dishonesty.
This is an evidence to look for when observing a person's reaction to a question who has no need to be afraid or nervous.
Biting the lips is a sign of stress. But sometimes it can be an accordion as well as a situation.
Minor and transient stress is decreased. Someone who is apprehensive and dishonest may also bite the inside of their cheek.
If someone folds his lips before answering something, it means either he will lie or does not want to answer you.
It can also mean that he does not want to say something that he really wants to say.
Such a large smile which includes cheeks, mouth and eyes too, then it can be fake.
As a result, if your discussion partner appears overly eager, they may be lying. The truth-tellers closed their eyes and smiled less.
When people are nervous, their voice tone changes, in other words, it becomes heavy. This produces higher-pitched voices.
Pitch may be less susceptible to planned behavior than characteristics, making it a valuable deception flag.