Sigmund Freud believed that personality is not something we are born with fully formed. It is built, stage by stage, through childhood experiences. And the experiences of the earliest years, the ones most people cannot even remember, are the ones that leave the deepest mark.
His theory is called the Psychosexual Stages of Personality Development. It is one of the most studied and debated frameworks in psychology, and whether you agree with every part of it or not, the core message is hard to dismiss: what happens to a child in their early years shapes the adult they become.
Freud identified five stages. Each stage is centered on a specific part of the body that becomes the focus of a child's energy and experience during that period. He called these erogenous zones. For a child to move healthily from one stage to the next, their needs at each stage must be met in a balanced way. Too much gratification or too little both cause what Freud called fixation, where a person gets emotionally stuck at that stage and carries its unresolved tensions into adulthood.
This article covers the first three stages.
The Oral Stage: Birth to 18 Months
In the first stage of life, a baby's entire world is experienced through the mouth. Feeding, sucking, swallowing. This is how an infant makes sense of everything around them, and it is also the primary source of comfort and pleasure during this period.
If a child's oral needs are not adequately met during this stage, Freud believed the adult they become may struggle with dependency, passivity, or a constant need for oral stimulation through eating, smoking, drinking, or nail biting.
In the later part of this stage, around eight to twelve months, the focus shifts to biting and chewing. A fixation here can manifest differently, through sarcasm, cynicism, and a tendency toward verbal aggression. Freud described this as the oral-sadistic character.
The Anal Stage: 18 Months to 3 Years
During this stage, a child's focus shifts to the anus and the experience of bowel control. This is the period of toilet training, and for Freud, how that process is handled by the parent matters significantly.
In the first part of this stage, pleasure comes from releasing. A child who becomes fixated here may grow into an adult who is overly generous or disorganized, what Freud called the anal-expulsive character.
In the later part, pleasure shifts to retaining. Fixation at this point can result in an adult who is excessively orderly, stingy, or perfectionistic. This is what Freud described as the anal-retentive character.
The broader point here is that how parents handle the toilet training period, whether with patience or with pressure and shame, has a lasting impact on the child's relationship with control, autonomy, and self-regulation.
The Phallic Stage: 3 to 6 Years
This is the most complex and most debated of the three stages. During this period, a child's awareness shifts to the genitals. Children at this age become curious about their bodies and the differences between male and female anatomy. Masturbation, as uncomfortable as it may be to acknowledge, is a normal part of this stage of development.
Freud also identified two significant psychological experiences during this stage. In boys, he described the Oedipus complex, an unconscious attachment to the mother and rivalry with the father, accompanied by castration anxiety. In girls, he described the Electra complex, involving an unconscious attachment to the father and what he called penis envy.
These concepts are the most controversial in Freud's entire body of work and have been widely criticized, particularly the ideas around female development. However, what remains relevant from this stage is the broader observation: children at this age are beginning to form their gender identity, navigate family dynamics, and develop a sense of themselves in relation to the people closest to them. How parents respond to a child's curiosity about their body and their identity during this period matters.
Fixation at this stage can translate into difficulties in adult relationships, sexual confidence, and the ability to handle competition and intimacy.
What This Means as a Parent
Freud's theory is not a checklist or a list of things to avoid. It is a framework for understanding that the experiences of early childhood are not neutral. They land somewhere. They shape something. The way a child is fed, toilet trained, and guided through their early years of body awareness all contribute to the adult they are becoming.
Early childhood care is not just about keeping a child safe and fed. It is about forming a person.