The physical and developmental facts about urination and defecation are simple and clear-cut as compared to the amount of theory and emotional concern these processes have generated. The healthy infant eliminates without showing any very noticeable reactions during the first month of life, but during the second month the bowel function is accompanied by flushing, leg tensions, and breathing changes. Defecation usually occurs after feeding and may be stimulated by warmth and cuddling. Tension and nervousness” apparently interfere with the process, as shown by the fact that infants who receive little or no mothering at home or in an institution are usually constipated (Ribble, 1944). In most cases, however, children respond readily to the muscular pressure patterns that signalize a “need.” They also come to assume the postural pattern of urination associated with their sex. Among human beings this is probably the result of imitative learning or direct teaching rather than constitutional differences, but Berg (1944) has found that among male and female dogs the differences in posture are due in part at least to the sex hormones.On the average, bowel control is achieved with occasional relapses by the time the child is ten to twelve months of age, and bladder control by the age two or two and a half. Gentle reminders that help the child become aware of his own needs are far more effective than nagging, threats, or overemphasis on cleanliness. Any form of pressure may arouse tensions and resentments which hold back the learning process.Many psychologists and psychiatrists believe the child experiences his first feelings of power and productivity during elimination. This helps to account for the pride he takes in his own “products,” and also his desire to handle the material he has produced as well as similar materials such as clay, mud, and finger paint. The eliminative process also stimulates normal curiosity which can usually be satisfied by touching the feces once or twice. This curiosity usually extends to the toilet itself, but once the child is shown how it works he will no longer be particularly interested in it. However, it is important to avoid the suggestion that he might fall into it or be flushed away, since this would lead to emotional tension and interfere with the rather delicate process of learning bowel and bladder control.Some theorists, especially of the psychoanalytic school, go much farther in this direction and hold that touching the feces is such a basic expression of curiosity that the child may become generally inhibited if it is not gratified. This school of thought also maintains that the eliminative processes are one of the fundamental expressions of the libido, and therefore provide erotic pleasure. At the same time the child finds that he can exert power over others by “holding back.” If he does not adequately “work through” both these phases of the “anal stage,” he may become overconcerned with “bathroom jokes” and anal forms of sexual expression, or he may develop a rigid or sadistic “anal character.” The analytic school also points to certain cases of advanced schizophrenia in which patients devour their own waste products. This school explains such behavior on the ground that (a) the patients are reverting to the infantile stage in which the child does not differentiate between himself and what comes out of himself, and (b) they consume their own wastes for fear that they are losing a part of themselves.The eliminative system is intimately associated with emotional expression through the activity of the autonomic nervous system. Tension, such as stage fright, usually leads to frequent urination or defecation, and intense fright may precipitate an involuntary voiding of the bladder and intestines. This is supported by a study of Shaffer (1947), who found that 5 per cent of war pilots experienced this reaction during or shortly after flying a combat mission. Other emotional upheavals can also produce the same effect, as shown by the fact that many people urinate involuntarily during a fit of laughter.