From The Art and Popular Culture Encyclopedia
The oral stage in psychology is the term used by Sigmund Freud to describe the child's development during the first 0 to 18 months of life, in which an infant's pleasure centers are in the mouth. This is the first of Freud's psychosexual stages.
This is the infant's first relationship with its mother; it is a nutritive one. The length of this stage depends on the society. In some societies it is common for a child to be nursed by its mother for several years, whereas this stage is much shorter in other societies. This stage, especially in some tribal societies, holds special importance because they consider the stomach to be the seat of emotions. These societies that see this stage as medicinal are commonly found in the Southwest Pacific and Africa, something which is referred to by Hilary Jacobson in her book, 'Mother Food for Breastfeeding Mothers'.