Why do I bite my nails so much?

As we said in the previous entry, several people have been sending in e-mails, asking about their nail biting habit. Pretty much all of them wanted to know the same three things:

Why do I do it?
Is it really bad for me?
How do I stop?

It seemed natural to begin with some information on causation. There are, as you'd expect in psychology, several theories on what causes chronic nail biting. Broadly speaking, there are psychoanalytic theories, psychopathological models, and cognitive-behavioural explanations.

For those of you familiar with the psychoanalytic tradition, it will come as no surprise to you that nail biting is conceived of as a maladaptive strategy for releasing sexual tension and/or other forms of frustration and aggression. These largely subconscious conflicts emerge in self-destructive behaviour, like nail biting.

While psychoanalytic theories of nail biting usually link nail biting to self-mutilation and eating disorders, most other researchers are inclined towards comparing nail biting with anxiety disorders like obsessive-compulsive disorder. In this view, nail biting is often thought to be an impulse control disorder (of which hair pulling, kleptomania, and pyromania are other examples) in the obsessive-compulsive spectrum. Alternatively, some treat nail biting as a subclinical variant of an obsessive-compulsive spectrum disorder. The motivation behind this classification of chronic nail biting as a OCD-spectrum disorder is that nail biting is thought to share similar neurophysiological roots with OCD-spectrum disorders.

Finally, cognitive-behavioural theorists think that chronic nail biting may have less to do with neurophysiological problems than maladaptive learning. Nail biters, argue cognitive-behavioural folk, have learnt (either from others or by accident) that nail biting is relaxing (and therefore psychologically rewarding), especially in times of stress, anxiety or boredom.

Now, none of these theories are really mutually exclusive. Most researchers concede that in any given individual, chronic nail biting may well be caused by underlying anxiety, neurophysiological dysfunction, and operant learning, all at a go. Furthermore, nail biting is one of those habits that is thought to be aetiologically pluralistic. Again, most researchers concede that different nail biters may develop the habit in different ways: Some may suffer from anxiety disorders, some may simply have picked up the nasty habit from their parents. This explanatory pluralism has implications for treatment, as treatment is often chosen based on aetiology. Before we go into that however, watch out for the next entry on the effects of nail biting.