What is the function of nail biting: an analog assessment study

OBJECTIVE: To compare the frequency of nail biting in 4 settings (interventions) designed to elicit the functions of nail biting and to compare the results with a self-report questionnaire about the functions of nail biting. DESIGN: Randomised allocation of participants to order of conditions. SETTING: University Psychology Department. SUBJECTS: Forty undergraduates who reported biting their nails. INTERVENTIONS: Left alone (boredom), solving maths problems (frustration), reprimanded for nail biting (contingent attention), continuous conversation (noncontingent attention). MAIN OUTCOME MEASURES: Number of times the undergraduates bit their nails. RESULTS: Nail biting occurred most often in two conditions, boredom and frustration. CONCLUSION: Nail biting in young adults occurs as a result of boredom or working on difficult problems, which may reflect a particular emotional state. It occurs least often when people are engaged in social interaction or when they are reprimanded for the behavior.