Based on Chapters Two and Three of Gay, Straight, and the Reason Why: The Science of Sexual Orientation by Simon LeVay
Chapter Two – Why We Need Biology
The primary nonbiological theories for the origin of sexual orientation have encouraged the search for biological explanations. As a whole, these theories and their weaknesses make clear the need for biology in understanding sexual orientation and homosexuality.
- Psychoanalytic Theories (pioneered by Sigmund Freud)
A. In males, the erotic instinct, also called the libido, is directed towards other males early on in life. This libido is later usually transferred to the mother in the infamous “oedipal stage.” In pre-oedipal homosexuality this transfer process doesn’t occur or is interrupted, causing lifetime homosexuality.
B. In oedipal homosexuality, a young male is frustrated by his inability to be with the mother that he is so attracted to. He resolves this frustration by identifying with her and seeking male partners that remind him of himself.
C. In females, the young female suffers from an unresolved oedipal complex that has been redirected towards her father. She falls in love with women who represent the mother she has grown to love and hate.
The problem with these theories: There is no evidence, and the complexity and improbability of them count against their being true.
- Learning Theories (Early Sexual Experiences)
A. A person’s first sexual contact determines their orientation. If their first contact is with a woman, then they will desire women, if with a man, they will be attracted to men.
The problem: Most people are aware of their sexual orientation as virgins. Also, young men in some non-Western cultures and single-sex boarding schools where sexual contact with other boys is common are no more likely to become homosexual adults.
B. Children who are molested are turned off the sex of their molester; e.g. girls who are molested by men become lesbians.
The problem: Since almost one-third of women will have an experience fitting a broad definition of sexual abuse, yet much less than one-third of women are lesbians, this theory is not likely true. Also, studies have found that lesbians are no more likely than straight women to have been abused as children.
- Learning Theories (Gender Learning)
Children, after becoming aware of their gender, learn their sexual orientation from imitation of parents or others in their social environment.
The problem: Children who are reared as the opposite gender due to tragedies during infancy (e.g. males who lose their penis due to disorder or surgery) do not accept this gender. They are attracted to others of their assigned gender and in most cases, revert back to their original gender.
Chapter Three – Outline of a Theory
The basic pathway that controls the development of sexual orientation (and other traits concerning gender) in nonhuman animals:
- Differences in sex hormone levels during development cause the brain to organize in a more male or female-like manner. These hormone levels are also modified by random variability, genetic differences, and environmental factors.
- Early sex hormone levels and the resulting differences in brain development influence preference for male and/or female partners later on in life.
This pathway appears to be the same route by which humans develop sexual orientation.
Gay, Straight, and the Reason Why Series:
- Introduction and Chapter One — What is Sexual Orientation?
- Chapters Four and Five — Childhood; Characteristics of Gay and Straight Adults
- Chapters Six and Seven — The Role of Sex Hormones; The Role of Genes
- Chapters Eight and Nine — The Brain; The Body
- Chapters Ten and Eleven — The Older-Brother Effect; Conclusions