Everyone exhibits styles of movement and speech, traits and habits which are characteristic of them as people but do not contribute dir­ ectly to their purposeful activity at anyone time. Many of these will be expressions of personality of which the individual may be unaware or even cherish and which evoke a favorable or neutral response from others. Conversely, displays such as gross involuntary tics or compul­ sive rituals are a burden to the sufferer and are socially embarrassing or obnoxious. These may be manifestations of a more fundamental neurotic disorder or the product of deep-seated maladaptive learning. Nail-biting occupies a central position along such a spectrum. Al­ though it may serve as a tension-reducing or other functional device, few nail-biters would not wish to be rid of the habit but find it as difficult to eliminate as, say, an addiction to smoking. Even so, it cannot be considered abnormal in a psychiatric sense in that many nail-biters exhibit none of the traits and symptoms characteristic of mental disorder.