Sigmund Freud's psychosexual theory of development suggests that early childhood experiences significantly shape personality and behavior. Freud proposed that development is discontinuous, occurring in five distinct stages, each defined by a focus on different erogenous zones. He believed that failure to resolve the conflicts specific to each stage successfully could result in fixation, potentially influencing behavior as adults.

The Five Stages of Psychosexual Development

Freud's psychosexual stages begin with the oral stage, which spans from birth to 18 months, where the infant's pleasure centers on activities involving the mouth, such as sucking and biting. Unresolved conflicts during this stage, such as premature weaning, may lead to fixation, resulting in behaviors like smoking or overeating in adulthood.

The second stage, the anal stage, occurs between 18 months and 3 years. During this period, children derive pleasure from controlling bladder and bowel movements. Freud suggested that overly strict or lenient toilet training could cause an anal-retentive personality, which is characterized by orderliness and rigidity, or an anal-expulsive personality, marked by messiness and disorganization.

In the phallic stage that occurs between 3 to 6 years of age, children become aware of their genitals and experience the Oedipus or Electra complex, a controversial concept in which children feel unconscious sexual desires toward the opposite-sex parent and view the same-sex parent as a rival. Fixation at this stage could affect future romantic relationships.

Following this is the latency stage, which occurs from ages 6 to 12 years, or puberty, during which sexual impulses are repressed, and children focus on developing social skills.

Finally, the genital stage begins at puberty, with the reawakening of sexual urges directed toward others, ideally leading to healthy adult relationships.

While Freud's theory remains influential in understanding early psychological development, it has been widely criticized for lacking empirical support. Many of its concepts, such as the Oedipus complex, are no longer accepted by contemporary psychologists, and his focus on sexuality has been seen as overly deterministic.