Patients evacuated to a naval hospital in this country from the Pacific battle area because of nervous conditions, excluding psychoses and psychopathic personalities, were examined in regard to nail biting. From routine admissions, 100 nail biters were collected. The frequency of the condition was determined. By studying the personalities, service and combat reactions of these patients, an effort was made to throw some light on the personalities of nail biters and the military usefulness of those who bite their nails. A comparative study was made on 100 nail biters who had experienced combat, who had no sick list admissions because of nervousness, and who were separated from naval service by the point system.Abstract Teaser