Psychophysiological reactivity to stress in nail biters

Heart rate and skin conductance were measured for 83 college students (20 male nail biters, 19 male non-nail biters, 22 female nail biters, and 22 female non-nail biters) during baseline, task, and 3 stressors. Psychodiagnostic measures included the Beck Depression Inventory and the State-Trait Anxiety Inventory. A significant nail-biting status x sex interaction was found in skin conductance reactivity (task minus baseline) for all tasks. Male nail biters were significantly more reactive than the other 3 groups. There was no significant difference in heart rate reactivity in any of the tasks. None of the psychodiagnostic measures differentiated among any of the subgroups. Nail biting, for males, is associated with psychophysiological changes during stress, although the implication of this relationship remains to be clarified.