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Nail biting can be defined as a habit because it is a behavior that is learned during the process of growth and development and therefore become automatic and people with the habit are usually unconscious of this action when they are doing it. Nail biting can be defined as a disorder because it is an obsessive compulsive disorder in the sense that individuals suffering from this disorder do it repeatedly in a routine manner. In addition, certain psychological states such as stress or depression can provoke or increase the intensity of this disorder.
Between-subject method can be used to determine if nail biting is a habit or a disorder by placing participants with this behavior in different categories. One group of subject should be treated with medication used for treating obsessive compulsive disorder while the other group of subjects should be helped to unlearn the habit by keeping their nails short and be discouraged from nail biting. The results for the two different treatments for the subjects are then compared. If the results of treatment for obsessive compulsive disorder show more improvement or cessation of nail biting, then the condition can be regarded as a disorder. If the other results from unlearning of the habit show the cessation of nail biting, the condition can be regarded as a habit.
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