body language

Sitting or standing in a High head position implies attentive listening, usually with an open or undecided mind, or lack of bias. It may also suggest analyzing what the speaker is saying.

Head tilted to one side suggests vulnerability, which in turn suggests a level of trust. Since tilting the head changes the perspective offered by the eyes it gives a different view on a subject.

Head forward in the direction of a person or other subject indicates interest. It also suggests coming into a closer personal space zone of the other person.

Head tilted downwards towards a person shows a signal of reprimand or criticism or disapproval, usually from a position of authority.

Vigorous head nodding indicates that the speaker has made his point or taken sufficient time. It is like a signal which tells the speaker to stop and shows disinterest

Biting your lip may signal or suggest tension, anxiousness or stress, which can be due to high concentration on a particular job or before an interview. It may also suggest holding the words in the mouth. Can also indicate anxiousness or impatience at not being able to speak.

Often an unconscious gesture of self-regulation - stopping speech for reasons of shock, embarrassment, or for more tactical reasons. The action can be observed very clearly in young children when they witness something 'unspeakably' naughty or shocking. Extreme versions of the same effect would involve both hands.

Nail-biting is an inwardly-redirected aggression borne of fear, or some other suppression of behaviour. It becomes a comforting habit later, again typically prompted by frustration or fear. Stress in this context is an outcome. Stress doesn't cause nail-biting; nail-biting is the outward demonstration of stress.

Head nodding can occur when invited for a response, or voluntarily while listening. Head nodding when talking face-to-face one-to-one is easy to see, but you also detect tiny head nods when addressing or observing a group.

Slow nodding of head implies understanding and approving what other person is saying. However it can be easily faked. As with all body language signals you must look for clusters of signals rather than relying on one alone. Look at the focus of eyes to check the validity of slow head nodding.