Body language is the outward and visible display of our feelings and emotions when we communicate and is often carried out unconsciously or subconsciously.
For example, we may be trapped in a conversation with a person with whom we really do not have any liking. Common courtesy and politeness demands that we at least give the impression of listening to what they have to say but what we are really thinking is how we can justifiably escape from this person and get away from the whole situation. We may try not to offend the other person by simply walking away and ignoring what they have to say but our body language can give our true feelings away if they are correctly interpreted by the speaker.
For example, we may start fidgeting and moving around, crossing and uncrossing our legs and arms; we may not look at the person directly and let our eyes stray to other areas beyond the immediate vicinity of the speaker; we may constantly look at our watch to check the time. These signs of inattention can be communicated to the speaker who may or may not recognise them.
If we are truly interested in what a person has to say we will sit attentively, facing the person and looking at them directly. We may lean towards them so that we are relatively closer to them, thus conveying the message that we are really interested in what they are saying.
As with the use of the tone of voice, body language can be interpreted as being opposed to what is actually being said by the use of words when communicating. It can, therefore, be recognised that all three aspects of personal communication--the words spoken, the tone of voice in which those words are spoken and the accompanying body language all play a part in relaying the true meaning of what is being communicated.
If any one of these elements is in conflict with the other two elements, then the true meaning of the communication is received as being confused and thereby lost.