There has been a study in the institute Universitaire en santé mentale de Montreal and the University of Montreal, Canada, on the repetitive behaviour of pulling hair, biting nails and picking skin by some frustrated individuals. The result shows that the participants engage in this repetitive behaviour only when they are under stress, but not when they are relaxed. The study was conducted among 24 individuals having this behaviour and compared them with 24 others who do not have this. According to the authors of the study which is published in the Journal of Behaviour Therapy and Experimental Psychiatry-these results confirm that the participants engage in this behaviour when they are under stress or when they feel bored or frustrated, and as such are not simply "nervous" habits. Repetitive behaviour may be 'perfectionistic'. One of the authors, O'Connor explains the study's findings: "We believe that individuals with this repetitive behaviour may be perfectionistic, meaning that they are unable to relax and to perform tasks at a 'normal' pace.
They are, therefore, prone to frustration, impatience and dissatisfaction when they do not reach their goals. They also experience greater levels of boredom." However, as impulse control disorders are typically blamed on a person's upbringing or life experiences, these findings were considered significant as they offered a biological basis for these conditions.
