General Psychology

Major theories about the origins of sexual orientation

All of these theories have been offered to explain why some people are homosexual. Some of the theories focus only on homosexuality, assuming heterosexuality as default sexual orientation. Other theories focus on sexual orientation, offering explanations for both homosexuality and heterosexuality.
None of the theories focus on bi-sexuality.

Keep in mind that theories are ideas, not facts. Some of these theories are somewhat supported by research, though the quality of the research varies. Some of the theories are not supported at all by research.

For the in-class assignment, students will be asked to examine research results regarding sexual orientation development, determine which studies are relevant to each theory, determine whether each relevant study supports or refutes the theory, and come to conclusions about the degree to which each theory is supported by evidence.

PSYCHODYNAMIC/FREUDIAN THEORY

Male homosexuality is caused by a hostile, detached father and a dominating, overly-close mother (or other problems with parent-child or mother-father relationships).

CLASSICAL CONDITIONING THEORY

An accidental or chance association between a same-sex person and a feeling of
sexual arousal (and perhaps orgasm) leads an individual to develop a sexual attraction to individuals of the same sex. Continued sexual relations with members of the same sex further strengthen the association between same-sex people and sexual arousal.
If something is learned through classical conditioning, it can presumably be unlearned through conditioning-related techniques.

Slight variation on classical conditioning theory:
FIRST ENCOUNTER THEORY: An individual’s sexual orientation dependes on whether their first sexual experience-- their “first pleasure”-- was with a person of the same or opposite sex. Same-sex first sexual experiences make it likely that an individual will become homosexual.

ADULT HORMONE THEORY

Male homosexuality is caused by having lower-than-average levels of male hormones (androgens, especially testosterone). Female homosexuality is caused by having higher-than-average levels of male hormones or lower-than-average levels of female hormones (estrogen).

PRENATAL HORMONE THEORY

Homosexuality in males is caused by a prenatal deficiency in exposure to male hormones (androgens, especially testosterone).
Homosexuality in females is caused by prenatal exposure to an excess of male hormones (androgens, especially testosterone).

EARLY ONSET THEORY

The onset of sex drive is the critical period for the development of sexual orientation.
Early feelings of sexual arousal are often undifferentiated-- not stimulated by a specific person or experience, but probably more determined by "adolescent hormone surges." Because adolescents therefore often feel sexual arousal for no apparent reason (not apparent to them) and search their environment for a reason, they may conclude that someone near them caused the arousal.
If an individual has close interactions mostly with members of the same sex (homosocial bonding) during the onset of sex drive, the individual may attribute his/her first feelings of sexual arousal to someone of the same sex. Conversely, if heterosexual relationships are being encouraged and an individual has some close interactions with members of the opposite sex (heterosocial bonding) during the onset of sex drive, the individual will attribute his/her first feelings of sexual arousal to someone of the opposite sex.
Therefore
A) Onset of sex drive during a period of homosocial bonding (friendships
exclusively with members of the same sex) makes it likely that an individual will become a homosexual.
B) Onset of sex drive during a period in which heterosocial bonding (friendships & relationships with members of the opposite sex occur frequently and/or are expected by society) is emphasized makes it likely than an individual will become a heterosexual.
Because sex drive onset is a critical period in development, to whom (same sex or opposite sex) adolescents attribute their arousal during this period has lasting effects.

Relevant facts about the US:
In the US today, homosocial bonding occurs through age 11 or 12 for most kids.
In the US today, the average age of sex drive onset is age 12 for males, age 14 for females

This theory was developed by social psychologist Michael Storms, who is gay.
Storms, M. D. (1981). A theory of erotic orientation development. Psychological Review, 88, 340-353.

GENETIC THEORY

Homosexuality is an inherited, biologically determined phenomenon. DNA differences determine whether a person will be homosexual or heterosexual. There is a gene for homosexuality.

LeVay is currently one of the most visible proponents of this theory. His research is frequently covered in the popular media.

EXOTIC BECOMES EROTIC THEORY

People are sexually attracted to the exotic. For most people, members of the opposite sex is mysterious and "fascinatingly strange," and therefore become erotic. However, for a minority of people-- specifically those who were gender nonconforming in childhood, who felt alientated from the interests of others of their gender-- members of the same sex are mysterious and strange and therefore become erotic.
What determines childhood gender nonconformity? Perhaps genetic personality traits (such as activity level, aggressiveness)

This theory was developed by social psychologist Daryl Bem, who is bisexual.
Bem, D. (1998). Psychological Review
Nussbaum, E. (1998). Dr. Strangelove: Does the exotic become erotic? A Cornell [University] psychologist's bold new theory about who's gay and why. Lingua Franca, 8(4), 38-44. [also contains criticisms of the theory]