1 Yale University Medical School, New Haven, Connecticut 06510
In the recent article by our townsman, Dr. Hans H. Neumann, "PicaSymptom or Vestigial Instinct?" (Pediatrics, 46:441) the concept of vestigial instinct is used as part of the basis for discounting emotional deprivation as one of the most significant factors leading to pica in this country. Dr. Neumann's otherwise fascinating report does not define adequately what he means by instinct, nor does he use the word pica in its usual sense. He admirably describes how a mother in West Africa introduces her infant to a piece of wood for chewing.