If your conversation partner is biting her nails, she's probably bored or frustrated.
A study by Kieron O'Connor, researcher and director of the Obsessive-Compulsive Disorder and TIC Disorder Studies Centre at the Institut universitaire en santé mentale de Montréal, and his colleague Sarah Roberts showed that repetitive behaviours such as nail biting are not only linked to stress but also to perfectionism, susceptibility to frustration, impatience, dissatisfaction and boredom.
Repetitive behaviours such as nail biting are not only linked to stress.
The researchers in the Department of Psychiatry at Université de Montréal carried out their behavioural study with 48 volunteers—half of which had a compulsive habit such as nail biting, skin touching or hair pulling. The participants filled out a questionnaire to assess their emotions, including weariness, anger, guilt, irritability and anxiety, and were then exposed to four situations to provoke stress, relaxation, frustration and boredom. As it turns out, those with uncontrollable habits turned to them when they were bored or frustrated.
The experts concluded that the compulsive individuals may be perfectionists who are incapable of relaxing or carrying out tasks at a normal pace and who therefore more easily become bored, impatient or dissatisfied when they don't attain their objectives. They also experience higher levels of frustration. According to Kieron O'Connor, to change their habits, sufferers should pursue therapy to reduce their frustration and boredom and curb their compulsions rather than treat stress or anxiety.