Psychosexual Development Freud provided a theory of human development.  These ideas revolved around his terms for the five stages of early childhood. 

Psychosexual Theory on the Development of Personality Freud believed that personality develops through a series of childhood stages during which the pleasure-seeking energies of the id become focused on certain erogenous areas. This psychosexual energy, or libido, was described as the driving force behind behavior.

Psychosexual Theory on the Development of Personality If the stages are completed successfully, the result is a healthy personality. If certain issues are not resolved at the appropriate stage, fixation can occur. A fixation is a persistent focus on an earlier psychosexual stage. Until this conflict is resolved, the individual will remain "stuck" in this stage. For example, a person who is fixated at the oral stage may be over-dependent on others and may seek oral stimulation through smoking, drinking, or eating.

Oral Stage 0-18 months One of Freud's five psychosexual stages of development where pleasure is centered in and around the mouth. The oral stage is the initial stage of development. According to Freud, this is when infants will be found putting anything into their mouth including their thumbs.

Anal Stage (18-36 months) The anal stage is one of the stages in Freud’s psychosexual theory of development, which occurs in the second year of life. During this stage, the anus becomes the focus of sexual gratification. This occurs because the child finds sexual pleasure in the sensations that come with having or withholding bowel movements.

Phallic Stage (3-6 years) One of Freud's five psychosexual stages of development where pleasure is centered around the genital region. The phallic stage is the third stage of development and usually is between ages 3 and 7. It is this stage where the child learns that there is a difference between males and females.

Oedipus Complex Within psychodynamic theory, the Oedipus Complex occurs during the phallic stage and is a conflict in which the boy wishes to possess his mother sexually and perceives his father to be a rival in love. According to Freud, the child must give up his sexual attraction for his mother in order to resolve this attraction and move to the next stage of psychosexual development. Failure to do so would lead the child to become fixated in this stage. Typically the Oedipus Complex refers to a boy wanting to possess his mother, while the Electra Complex refers to a girl wishing to possess her father. But don't be surprised if some refer to the Oedipus Complex for both boys and girls.

Latency Stage (6 years to puberty) Latency is the fourth stage in Freud's Psychosexual theory of development, and it occurs from about age 5 or 6 to puberty. During the latency stage, a child's sexual impulses are repressed. The reason for this is that during the stage before latency (phallic stage) the child resolves the Oedipus or Electra Complex which are such traumatic events that the child then repress all of his or her sexual impulses. Interestingly, because this stage contains little or no psychosexual development, Freud was fairly uninterested in it.

Genital Stage (puberty on) The genital stage is the final stage in Freud's theory of psychosexual development and begins in puberty. During this stage, the teenager has overcome latency, made associations with one gender or the other, and now seeks out pleasure through sexual contact with others. The sexual contact sought has shifted from the opposite sex parent of the phallic stage (and overcoming this), and is now focused on opposite sex people of similar age. The pleasure that they gain is now through actual physical stimulation of the genitals by the opposite sex.