Onychophagia is characterized by thecompulsive urge to bite one's nails, often leading to tissue damage to the nails, cuticles, and surrounding skin. This can range from occasional mild behavior to deep self-mutilation. It typically involves the soft tissues surrounding the nail, the cuticle, as well as the nail itself. Common among children and young adults, it occurs in 20 to 33% of children and nearly 45% of teenagers.
This functional habit is typically not observed before the age of 3 or 4 years. Most cases of nail biting begin in early childhood, between 4 and 6 years, and stabilize from 7 to 10 years before intensifying in adolescence with the onset of puberty. However, in many cases, this behavior most often decreases with age: it spontaneously and completely stops at the end of adolescence or the beginning of adulthood.
Adults can also fall victim to this, particularly after experiencing high stress at work, undergoing a traumatic event (such as divorce, death, etc.), or in cases of withdrawal (from tobacco, alcohol, etc.). It has also been observed that boys significantly outnumber girls in nail-biting.
The reason why some individuals develop this particular habit or not is not entirely clear and understood. However, the need to bite one's nails is generally associated with a psycho-emotional state of anxiety due to the self-soothing effect it provides afterward. It is seen as a reflex of emotional imbalances : a reaction to stress, fear, or excessive depression. Our emotional makeup (shyness, low self-esteem) also plays an integral part in why we turn to nail-biting.
Onychophagia also has a strong correlation with personality. Thus, some impatient individuals or those prone to frustrations often bite their nails frenziedly to channel their excess energy and regulate their emotions. This behavior can also occur in an attempt to imitate someone, especially observed in children.