In the early 1900s, psychoanalyst Sigmund Freud introduced the theory of psychosexual development. He believed children experience five psychosexual stages that determine their behavior as adults.

According to the theory, a child is sensually aroused by certain stimuli during each stage. These stimuli are said to satisfy developmental needs.

But if a child’s needs aren’t met during a specific stage, they can develop a fixation or “hang-up” related to the phase. In adulthood, these unresolved needs may be expressed as negative behaviors.

If the hang-up occurs during the oral stage, it’s called oral fixation. The oral stage is when a child is most aroused by oral stimulation. Freud said oral fixation causes negative oral behaviors in adulthood.

However, there aren’t any recent studies on the subject. Most of the available research is very old. The theory of psychosexual development is also a controversial topic in modern psychology.

In the psychosexual theory, oral fixation is caused by conflicts in the oral stage. This is the first stage of psychosexual development.

The oral stage occurs between birth to about 18 months. During this time, an infant gets most of their pleasure from their mouth. This is associated with behaviors like eating and thumb-sucking.

Freud believed an infant can develop oral fixation if their oral needs aren’t met. This could happen if they’re weaned too early or late. In this scenario, they’re unable to appropriately adjust to new eating habits.

Oral fixation might also occur if the infant is:

  • neglected and underfed (lack of oral stimulation)
  • overprotected and overfed (excess oral stimulation)

As a result, these unmet needs were believed to determine personality traits and behavioral tendencies in adulthood.

In psychoanalytic theory, developmental issues during the oral stage can lead to the following behaviors:

Alcohol abuse

Freud’s theory says alcoholism is a form of oral fixation. It’s thought that this is related to the link between childhood neglect and alcohol abuse.

Specifically, if a child is neglected during the oral stage, they can develop a need for constant oral stimulation. This may increase their tendency to drink frequently, which contributes to alcohol abuse.

Smoking cigarettes

Similarly, it’s said adults with oral fixations are more likely to smoke cigarettes. The act of moving a cigarette to the mouth offers the necessary oral stimulation.

It’s thought that e-cigarettes satisfy the same need. For some cigarette smokers, using an e-cigarette supposedly satisfies their oral fixation in the same way.

Overeating

In psychoanalytic theory, overeating is seen as an oral fixation. It’s associated with being under- or overfed early in life, leading to emotional conflicts during the oral stage.

This is thought to create excess oral needs in adulthood, which may be met by overeating.

Pica

Pica is the consumption of nonedible items. It may develop as an eating disorder, habit, or stress response. The idea that pica could be related to oral fixation is based on Freudian theory.

In this case, excessive oral needs are satisfied by eating nonfoods. This might include substances like:

  • ice
  • dirt
  • cornstarch
  • soap
  • chalk
  • paper

Nail biting

According to Freudian psychology, nail biting is also a form of oral fixation. The act of biting one’s fingernails fulfills the need for oral stimulation.

Oral fixation can be treated. Generally, treatment involves reducing or stopping negative oral behavior. It may also include replacing the negative behavior with a positive one.

Therapy is the main component of treatment. A mental health professional will help you explore underlying emotional conflicts, along with healthier coping strategies.

For example, if you bite your nails, a mental health specialist might focus on managing emotions that trigger nail biting. They may also suggest chewing gum to keep your mouth occupied.

Other components of treatment depend on the behavior and its side effects. Pica, for instance, might require nutritional intervention to correct vitamin and mineral deficiencies that may be present.

In Freud’s psychosexual theory, there are five stages of development:

Oral stage (birth to 18 months)

During the oral stage, a child is most stimulated by the mouth. They might develop negative oral behaviors in adulthood if these needs aren’t met.

Anal stage (18 months to 3 years)

A child’s pleasure comes from controlling their feces. If potty training is too strict or lax, they may have issues with control and organization in adulthood.

Phallic stage (3 to 5 years old)

In the phallic stage, the focus of pleasure is on the genitals.

According to Freud, this is when a child is subconsciously sexually attracted to the parent of the opposite sex. This is called Oedipus complex in boys and Electra complex in girls.

Latency period (5 to 12 years of age)

The latency period is when a child’s sexual interest in the opposite sex is “dormant.” The child is more interested in interacting with children of the same gender.

Genital stage (12 to adulthood)

This marks the start of puberty. Freud said adolescents are most stimulated by the genitals and the opposite sex.

In Freudian psychology, oral fixation is caused by unmet oral needs in early childhood. This creates a persistent need for oral stimulation, causing negative oral behaviors (like smoking and nail biting) in adulthood.

Though this theory is well known, it has received criticism from modern psychologists. There also isn’t any recent research on oral fixation.

But if you think you have an oral fixation, see a mental health professional. They can help you manage your oral habits.