What was the basis of Freud's thinking for psychosexual thinking?

What natural reflexes and stages do children go through in relation to their sexual development
(organ wise)

Freud has, among other things, been involved in the study of sexuality in humans.

Explanation:

According to Sigmund Freud, this stage of maturation development is divided into five stages. Freud believes that human development involves the transfer of libidinal energy from one area to another, so the developmental stages he talks about are related to particular parts of the body. The creator of psychoanalysis emphasized that his notion of sexuality was different from every day, generally known meaning.

For him, adult sexuality is just one particular aspect called genital sexuality. The creator of psychoanalysis emphasized that his notion of sexuality was different from every day, generally known meaning. For him, adult sexuality is just one particular aspect called genital sexuality.The elements of sexuality, according to Freud, occur from the earliest ages of the child, but the final phase (Genital phase) begins at the age of twelve.

see below  

explanation:

all of the above