There are several different environmental factors which various overlapping schools of thought hypothesize influence the determination of sexual orientation.
One of the most important questions in this area (and in the larger cultural and political debate) is whether sexual orientation is a stable attribute fixed early in life, or can be changed or chosen in adolescence or adulthood. In this case, the primary aspect of sexual orientation which is of interest is whether spontaneous attractions are for members of the same, opposite, or both genders. (For discussion about whether or not there are exactly two genders and what constitutes gender, see the article on sex.) Obviously, for the purposes of sexual behavior, any person may choose to follow or resist their spontaneous feelings, and self-identification is a psychological and social phenomenon distinct from sexual behavior and attraction.
Various environmental causes have been proposed by advocates of both the "fixed attribute" and "choice" hypotheses.
Empirical studies which attempt to quantify non-genetic influence on sexual orientation (from whatever sources) are discussed in Genetics and sexual orientation.
Early fixation hypothesis
If sexual orientation is fixed early in life, when exactly does that happen, and how? The following "environmental" mechanisms (as opposed to (genetic mechanisms) have been proposed.
Hormone exposure
Over-exposure to testosterone in the womb is hypothesized to cause homosexuality in males.
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Imprinting
This theory holds that the formation of gender identity occurs in the first few years of life after birth, influenced by unconscious differences in the way adults behave toward children of different genders, and the roles that very young children see adults filling. Part of adopting a gender identity involves establishing the gender(s) of sexual attraction. This process is analogous to the "imprinting" process observed in animals. A baby duckling may be genetically programmed to "imprint" on a mother, but what entity it actually imprints upon depends on what objects it sees immediately after hatching. Most importantly, once this process has occurred, it cannot be reversed, any more than the duckling can hatch twice.
A sort of reverse sexual imprinting has been observed in heterosexual humans; see the section on the "Westermarck effect" in Behavioral imprinting.
Chance events
The human brain is a complex organ in a complex organism, and sexual attraction is a difficult feature to construct reliably each time. It is possible that more or less random events in the internal development of the brain sometimes result in atypical structures which correspond to atypical sexual orientations.
A simple analogy is the growth patterns of trees. Even genetically identical trees will have differently-shaped branches. Many factors contribute to these differences - accidents in the formation of the seed, the randomness of Brownian motion, slightly different soil, wind, water, and lighting conditions, etc. As a result, one tree may end up with 49 apples, the one next to it, with 51.
Choice hypothesis
If sexual orientation is a conscious choice, then social and culture influences no doubt play a large role, as they do in "lifestyle" choices like what foods to eat or how to throw a birthday party.
Some advocates of the choice hypothesis believe that sexual orientation is not a choice which is necessarily made casually or easily changed. Most choice advocates also have a negative view of non-heterosexual orientations. So they might, for instance, consider homosexuality to be a personal problem not unlike a drug or alcohol addiction. A person might not be able to change without help, but in the end, their own choices and behaviors are an integral part of their "problem".
Changing sexual orientation through therapy
Most gay, lesbian, and bisexual people, and many straight people, believe that sexual orientation is not a choice. Most contemporary psychologists consider "reparative therapy" - trying to actually change a patient's sexual orientation from, say, homosexual to heterosexual, through therapeutic means - to be ineffective, if not psychologically harmful.
However, there is also a modern ex-gay movement that claims that homosexuals can become heterosexual or otherwise "leave homosexuality behind" through counseling, prayer, and other therapies if they choose to do so.
See Homosexuality and psychology.
Moral and religious considerations
Religious authorities regarding homosexuality as wrong or "sinful" often distinguish between immoral sexual acts and non-heterosexual feelings. Adherents to these codes of conduct are often advised to abstain from sexual acts in general, or to attempt to foster opposite-sex relationships; celibacy is an acceptable or sometimes even admirable alternative to heterosexuality. (For example, the Roman Catholic Church.) Some religions hold heterosexual marriage to be morally superior to celibacy, or mandatory for entry into a desirable form of the afterlife. (For example, the Church of Jesus Christ of Latter-day Saints.)
Not all religious sects regard non-heterosexual orientations as wrong, nor do all adherents of organized churches that do hold that view. See religion and homosexuality for a more complete discussion.
Proponents of the "choice about behavior" position point to taboo or illegal sexual acts, such as pedophilia or incest where society requires individuals not to act out their desires, as examples where choices are expected to be made whether or not orientation is a matter of choice.
External links
On the issue of choice
Last updated: 12-26-2004 01:35:46
