Sigmund Freud, a psychologist in the 20th century, published his views about sexuality and children. He coined different phases that a human will go through as they develop. According to Freud, each stage has to be resolved before the next one starts. If someone gets stuck in a stage, they could have developmental problems later in life. The first stage is oral, occurring from birth to one year; where the infant fixates on their mouth by biting, sucking, breastfeeding, etc. This can sometimes come up later in life as people who bite their nails or smoke. The second phase is anal, where from one to three years a child is very impressionable on potty training. The way you are trained also develops some of people’s later relationships with authority. The phallic stage is next, when children are three to six years old. This is the Oedipus complex, where sons are attracted to their mom and daughters are attracted to their father. This is resolved through identification, and this phase is also where the concentration on the genital areas appears. Freud goes into other stages such as latency and genital, but those are for puberty and doesn’t so much concern a child. As it can be seen, Freud brought some revolutionary thought into his time. All of his findings were experimental, and came with a lot of controversy.