THE DIFFERENTIAL diagnosis of organic from psychogenic pain had long confounded pediatricians and psychiatrists alike. The sympathetic components of anxiety may blanch the viscera and be described as pain, and an unnecessary laparotomy is sometimes the result.1 The clinical method of avoiding such an unfortunate error is to estimate through interview whether the child's history and personal reactions approach organic or emotional patterns. A few cases have textbook clarity in either direction, but most are clouded by problems. Practical problems arise, such as a child being too immature to discuss symptoms; and problems of clinical judgments, such as estimating whether the child's urgent complaints are hysterical drama or growing peritoneal irritation. An objective measure of fluctuations in anxiety is the Galvanic Skin Response (GSR), which is a change in skin resistance to the passage of a small externally applied electric current. Probably related to sympathetic flow from hypothalamus to