The Gallop poll periodically asks a statistically significant sampling of the American
public whether homosexuality is caused by nature or nurture. That is, whether it is:
a biological trait with which people are born, or
due to other factors, such as upbringing or environment. 1
The correct question has already been determined, at least for males, by pedigree studies and by
studies of the sexual orientation of identical twins, as described
elsewhere.
It appears that the tendency towards homosexuality is determined genetically. But that
this tendency may or may not be triggered during childhood into inducing a homosexual orientation
later in life. Thus, for males, the answer which agrees with medical research is: both a
biological trait and environmental triggering factor. The gap between science and public opinion
appears to be widening. The percentage of people who gave the "both" answer has
dropped from 14% to 6% over the period 1977 to 1998.
Asking the public about the causes of sexual orientation is like inquiring their belief
whether the universe was created or evolved. The answer only tells us of people's beliefs;
it has no impact on the actual causes of homosexuality.
Date
"Born with"
Other factors (e.g.
upbringing, environment)
Both
Neither
Don't know
1977-JUN
13%
56%
14%
3%
14%
1982-JUN
17
52
13
2
16
1989-OCT
19
48
12
2
19
1996-NOV
31
40
13
3
13
1998-JUN
31
47
6
3
13
In a separate question, 63% of respondents agreed that the cause of homosexuality
"depends upon the person." Fewer than 20% said that there is only a
single cause of homosexuality for all persons.
The margin of error of the poll is within 5 percentage points, 19 times out of 20.
When human sexuality researchers talk about the causes of sexual orientation, they
normally try to consider two determinants: genetic and environmental factors. Separating
the two factors is not easy. "Pedigree studies" show that there is a strong
genetic component to homosexuality. But the "identical twins separated at birth"
studies have shown that genes do not completely determine sexual orientation. Some
environmental influence after conception (perhaps before birth) might trigger one or more
"gay genes" in some people. The absence of this influence in other
individuals would cause the gene(s) to remain dormant.
Some suggested causes are:
A bacterial basis for sexual orientation: Biologist Paul Ewald and Physicist Gregory Cochran theorize that
homosexuality orientation may be caused by a bacteria or virus. Their reasoning
is indirect. Any genetic trait that reduces a person's chance of procreating is
said to have a "fitness cost." A trait that has a fitness cost of 1%
lowers the probability of having children by 1%. The cost would cause the trait
to essentially disappear within 100 generations. Homosexuality has a
"fitness cost that is much higher than 1%." A 1981 study in San
Francisco showed that gays and lesbians have only 20% of the number of children
as do heterosexuals; i.e. the fitness cost factor among that sample of
homosexuals is 80%. This number was probably much lower in the past, as gays and
lesbians were often forced into marriages in order to escape detection. But it
would only have to be 0.001% to wipe out the trait in the lifetime of the human
race. 8
Since homosexuality has not disappeared and yet appears to have a high
fitness cost, the researchers speculate that the trait is at least partly
determined by some outside agent, like an infection.
There is a good chance that this theory will not pan out. Infections tend to
peak in a few geographical areas and/or during a few years duration. Yet there
are no obvious concentrations of gays and lesbians who spent their childhood in
the same area or who are of nearly the same age. A second possible criticism of
the theory might be that homosexuality may have a sufficient advantage to society
to overcome its fitness cost.
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Hormones: One theory promoted by Dr. Gunter Doerner of East Germany and other scientists is that
sexual orientation can be determined by exposure to specific hormones before birth. A
persons gender is determined at conception. But it is only about the 6th week of pregnancy
that the fetus start to develop either female ovaries or male testicles. The theory is
that hormones produced by the developing testes might be produced off schedule and cause
the brain's neural networks to develop in such a way that the child will exhibit
homosexual indicators in early childhood, and that he will mature as a gay male. Lab
experiments on rats and monkeys have proven that this sequence happens in other species.
9
Needless to say, it is ethically impossible to perform the same experiments on humans.
Demonic Possession: Some very conservative Christians believe that homosexual orientation is caused by
indwelling demons. This is a natural result of their belief in the inerrancy of
the Bible. The New Testament discusses how countless demons under the authority of
Satan roam the world, attempting to lead people into sin and causing both mental
and physical illnesses. Since they believe that the Bible is
inerrant (without error), then demons and
Satan must exist. J.F. Gogan writes about demons: "Where
illicit sex is already practiced, they flock to that site as observers and
catalysts. Where it is not happening, they attempt to infest those vulnerable to
evil supernatural powers with lust. You became homosexual...when one or more of Satan's demons
detected your susceptibility to demonic influence. This susceptibility could have been brought
on by any one, or a combination of causes. Perhaps you were drawn into homosexual activity by a
same-sex friend who was also troubled by a demon. Or perhaps a demon convinced
you were a man in a woman's body or vice versa." 10
Parenting: Other conservative Christians believe that the roots of
homosexual behavior are found in childhood, if the child is unable to form a
loving relationship with the parent of the same gender. A son, for example,
would take this incompleteness into adulthood, where he would continue to seek
love from another adult of the same gender. The result is a sexually active
relationship. They believe that the cure is reparative
therapy, in which the client develops a loving but non-sexual relationship
with a person of the same gender. This completes the person's longing, and
converts them to heterosexuality. Although this belief system is generally
accepted by conservative Christians, articles about the effectiveness of
reparative therapy have never been published in peer-reviewed journals. Anecdotal
evidence from conservative Christian therapists indicates that this therapeutic
technique is generally successful. Evidence from other therapists indicates that
it invariably fails; they note that it often leaves the client in a depressed
mood, and is sometimes responsible for suicidal ideation.
Some conservative Christians researchers have conducted studies which appear to indicate a high rate of
parental dysfunction among some gays and lesbians. But other studies done by
investigators who are not conservative Christians find no
correlation between the incidence of homosexuality and parenting styles.
This effect is found quite often in the social sciences; study results
frequently tend to match the researchers pre-conceived beliefs more than they match
reality.
If lack of a relationship with one's father
causes male homosexuality, one would expect that the generation of American boys born in
the early 1940's would have a much higher incidence of homosexuality than other
generations, because so many fathers were away at war. One would also expect to
find a much larger percentage of male gays among men who had been raised without
a father present in a single parent family. We have been unable to find either
phenomenon mentioned in the literature.
Daniel R. Heimbach, "Notes for The Bible in the Moral War
over the Rejection of Homosexuality by the Military Services: A View from
Inside the Pentagon," PREMISE, Volume II, Number 7, 1995-AUG-27, Page 10.
Online at:
http://capo.org/