The idea for this volume grew out of a series of discussions among the members of the two editors' laboratories. Kenneth A. Dodge has been investigating aggressive conduct disorders in children, and Judy Garber has been examining internalizing disorders (depression and somatization) in children. It became readily apparent in our discussions that a common problem in these disorders is the children's inability to control, or regulate, their arousing and emotional states. Aggressive children fail to inhibit their responses and experience anger in the extreme. Depressed children withdraw in the face of emotional distress, and somatizing children excessively inhibit their expression of strong emotion.