When people are nervous, they fidget. Fidgeting involves moving with excitement. Hands, legs and other parts of the body make quick movements, with no particular aim. It is a reflex action, initiated by the subconscious mind. This, in fact, is a reaction to a tense or exigent situation. We do not know what to do but we know that we have to do something! Nail biting is one way of the body’s response to the call for doing something.
Sometimes, you may feel powerless against the situation. You are in a spot and you know that you are unable to do anything to extricate yourself from the situation. Here there is no feeling of nervousness but only a feeling of helplessness. Nail biting takes place as a passive response to a challenge against which you feel totally powerless. This is one reason why the habit of nail biting is more prevalent among children. Children often find themselves powerless to get what they want and start biting nails.
This habit learned in childhood is carried throughout. The only difference is that, grown up people will feel embarrassed to bite nails when they can be watched by others. We can see grown up people standing alone biting their nails and suddenly withdrawing their fingers from the mouth the moment someone comes towards them. In a way, this inhibition helps in making the habit less pronounced in grown up people.
Children sometimes face an unpleasant situation. They commit a mischief and are caught. When they are confronted by their parents or teachers, they just stand biting their nails. This is apparently a defense mechanism devised by the subconscious mind to prevent the children from doing something that could aggravate the situation. With both the hands and the mouth kept occupied, the children cannot say anything that will go against them, nor can they do anything using their hands. Nail biting becomes a harmless act compared to the alternative of speaking!
Over a period, this becomes a programmed reaction to unpleasant situations and gets entrenched as a habit. Thus, even when there is no problem, some people may keep biting their nails.
We have seen the psychological reasons for nail biting. There are also psychological effects of this habit, in addition to well known physiological effects. Since biting nails was originally conceived as a response to a negative situation, the mind begins to associate nail biting with problems. Thus the habit creates the situation of a problem in their day to day life in the mind’s perception, even when no problem exists.