Many well-defined physical illnesses in infancy reflect disturbances in the caretaking environment; these illnesses respond favorably to improved relations between the infant and his caretakers and to the establishment of a more stable, predictable pattern of care-taking within a socially stable and reliable caretaking relationship. In fact, a number of illnesses previously thought to have specific physical etiology are now known to be associated primarily with disturbances in the biopsychosocial matrix surrounding normal development. (37 pp.)