Freudian theory
divides child development into sexual stages.
Freudian psychological theory is not commonly used anymore, but it is still helpful to be familiar with it. Even though it does not have strong empirical evidence supporting it, it still gives good ideas for parenting. Freudian theory divides child development into five stages, all of which are associated with a different sexual organ.
Oral Stage
Since an infant is completely helpless, unable to even hold his own head up until he is a few months old, he interacts with the world through his mouth. Not only does he consume milk through his mouth, he also connects with his mother through his mouth. According to Freud, if someone is allowed to satisfy his oral urges whenever he wants, he becomes more impulsive, greedy and self-centered later in life; if he is not allowed to feed very often, the opposite happens and he becomes rigid, suspicious and pessimistic.
Anal Stage
One of the major milestones in a toddler's life is learning properly use the toilet; this is the anal stage. The conflict is between her basic desires and social pressure; her basic desires (or id) want to be able to defecate whenever and wherever she pleases, while social pressure dictates the opposite. Freudian theory dictates that a child who is allowed to defecate at her heart's content will become disorganized, reckless and generally free-spirited as her id is allowed to control more of her urges. A child who is made to defecate at specific times, on the other hand, becomes extremely neat, orderly and passive-aggressive as her basic desires have taken too much of a back seat to social pressure.
Male Phallic Stage
Four-to-five year old boys experience the phallic stage. This is where they start to see their penises as a source of sexual pleasure. Since they have previously experienced love for their mother, they focus this sexual energy on her -- the love they had for their mothers turns into sexual desire. They also become aware of the fact that girls do not have penises. Being four years old, they unconsciously connect these two facts, and conclude that girls are boys who lost their penises for being attracted to their mothers. The resulting castration anxiety leads them to bury their feelings for their mothers and subconsciously take on their fathers' character traits. If they cannot be with their mothers, they can vicariously do so by acting like their fathers.
Female Phallic Stage
Girls do not have castration anxiety, but they do have penis envy. When they realize that boys have penises and they do not, they become fixated on acquiring one. In order to do so, they take on their mothers' character traits -- if they cannot have a penis, they can take on the traits that lead them to acquire a man, which is the next best thing. It is important to remember that this is according to Freudian theory, not any theory that is commonly used today.
Latency
Latency is the period in which children have no conflicts to resolve. From the resolution of their phallic stage (at around age 6) to puberty, they play with same-sex peers and their gender does not play a role in their identity.
Genital Stage
Post-pubescent people are all in the genital stage. This is where romantic relationships begin to be cultivated. The success of this stage is completely dependent on the success of the previous stages. If someone was able to successfully, healthily resolve each of the preceding stages, then she will have a greater capacity for healthy relationships. If not, though, then she needs to resolve these before she can have healthy relationships.