Describe Freud's view of development as progression through psychosexual stages. What are some major criticisms of this theory?

Freud believed that nearly all human behavior could be
understood as a function of human's innate pleasure-seeking tendency. He posited that
during different developmental phases, humans fixated on specific areas of the body in
order to derive pleasure. The first developmental phase was the oral stage, lasting from
birth to age 1. During this stage, a person derives pleasure from his mouth, through
suckling on his mother's breast. The second stage, called the anal stage, lasts from
ages 1 to 3. During this stage, people derive pleasure from learning to control and
master their bodily functions. Freud posited that healthy individuals are those who pass
through these stages successfully, without becoming stuck in any one of them. He
believed that people who become stuck ("fixated") in one particular stage would not be
able to achieve healthy social and sexual maturity.

This
developmental schema is subject to a number of critiques. Cultural anthropologists point
out that these stages represent a culturally relative timeline and thus can't be
universalized. For example, in some cultures, the weaning stage lasts up to 4 years old.
Cultural differences in child-rearing are not adequately addressed in the psychosexual
theory of development.

Many psychologists believe Freud's
theory to be over-simplified and reductionist. Young people and adults alike derive
pleasure from a number of sources: bodily, emotional, social and cognitive. It may not
be useful to attempt reducing all pleasure-seeking activity to a function of latent
sexuality.

Social psychologists also point to Freud's
normalization of heterosexual male sexuality as a limiting factor. According to the
psychosexual theory of development, those who do not adopt heterosxual, male-oriented
sexuality are mentally ill. Thus, Freud's theory limits our ability to recognize the
validity of different sexual identities and expressions.