The oral stage is the first of a series of stages in the theory of psychosexual development proposed by Sigmund Freud, a noted 20th century psychoanalyst. Freud believed that healthy sexual development followed a series of stages, starting at birth, as people learned about their bodies and developed both positive and negative associations about specific areas of the body. At each stage, various events could contribute to a fixation on a particular area of the body which might manifest in the form of a psychological or sexual issue.
In the oral stage, which lasts from birth to around 18 months or two years, the fixation is the mouth. The mouth is the way in which the body intakes sustenance, with infants literally feeding their needs through the mouth. The mouth is also very sensitive, as is the area around the mouth, early in development. Many infants like to explore tactile sensations with their mouths, which is why they gum, chew, and lick things.
According to Freud, an infant who develops in a healthy way during the oral stage learns to trust people and develops a sense of comfort. The oral stage can also facilitate independence and the development of personal boundaries as infants start to learn that they can satisfy their needs. As the oral phase draws to a close, an infant can experience conflict during weaning, and then pass into the anal stage, which involves a fixation on the anus and the things which emerge from it.
If development during the oral stage does not progress in a healthy way, Freud believed that it could contribute to the development of an oral fixation. Individuals with an oral fixation might continue biting, chewing, licking, and sucking things as a form of exploration well into adulthood. Oral fixation was also credited as the motivating force for smoking, overeating, and other activities involving the mouth. Freud suggested that not meeting the needs of an infant during the oral stage could lead to an oral fixation, and that exceeding these needs could have a similar result.
There is a great deal of debate about the stages of psychosexual development. While many people in the field of psychology study them, because Freud had a tremendous influence on the field, not all practitioners lend credence to this theory. Others believe that while parts of the theory and the ideas behind it may be sound, childhood and sexual development are more complex, and this theory does not adequately explain all of the processes involved in healthy psychological development.