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Homosexuality:
Nature or Nurture
Ryan
D. Johnson April
30, 2003
In
recent decades, many hotly debated topics have come under the
scrutiny of sociobiologists, trying to determine their
causation and origins. One
such topic is homosexuality.
Originally thought by the American Psychological
Association (hereafter referred to as APA) to be a mental
disorder, research into its causes, origins, and development
have consequently led to its removal by the APA from its list
of diagnoses and disorders [1].
Many different theories can be found regarding the root
of homosexuality, as far back historically as Ancient Greece.
The current debate is whether or not homosexuality is a
result of nature: a person's environment and surroundings, or
of his biology and genetics.
The debate endures because both sides have the ability
to create a scientific environment to support their cause.
For example, biological theorists may argue that a
monkey and human child, reared in the same setting, will
develop with vastly different outcomes, while social theorists
may argue that monozygotic twins, one reared normally and the
other raised in seclusion for 18 years, will also develop with
vastly different results, but different even more from the
first scenario [4].
In
debating sexual orientation, much is unknown; according to
Charles Darwin, "...we do not even in the least know the
final cause of sexuality.
The whole subject is hidden in darkness." [2].
Although the APA currently states that sexual
orientation is not a choice, rather that "...it emerges
from most people in early adolescence with no prior sexual
experience"[1], social theorists argue that an
individual's upbringing can directly influence this [sexual
orientation]. Also
tied in with many of these debates is the morality of
homosexuality. But
the purpose of this examination is not to prove whether or not
homosexuality is right or wrong, but rather to establish a
thorough understanding of the biological and social theories
surrounding the cause of homosexuality.
Let
us first look at the biological debate.
Biological theorists have found substantial instances
of anatomical, genetic, and endocrine evidence to support
their argument. Experiments
in biological research date back as far as the late 1930's,
beginning with the pioneering research of Alfred Kinsey (for
the University of Indiana) on human sexuality.
Kinsey had two goals for his tests: 1) to find out how
many adult males engaged in homosexual behavior, and 2) to
suggest theories about it came to be [9].
When asked if they had engaged in homosexual sexual
relations, a large percent of the population tested answered
"no", however when asked if they had engaged in
same-sex sexual relations, the percentage answering
"yes" nearly doubled.
The experiment yielded that 30% of males had
experienced at least orgasm in a homosexual act.
The results of this research became the widely
popularized Kinsey Scale of Sexuality.
This scale rates all individuals on a spectrum of
sexuality, ranging from 100% heterosexual to 100% homosexual,
and everything in between [7].
While establishing that as many as 10% of adult males
reported having sexual relations with a same-sex partner, this
research did little more than to put the word homosexual into
common language.
Karen
Hooker executed the first psychological test done to test for
biological determinism in 1957, on a grant from the National
Institute of Mental Health [2].
The study was meant to explore the relationship between
homosexuality and psychological development and illness.
Hooker studied both homosexuals and heterosexuals.
Both groups were matched for age, intelligence quotient
(IQ) and education level, and were then subjected to three
psychological tests. These
three tests, the Rorschach, Thematic Apperception Test (TAT)
and the Make-A-Picture-Story Test (MAPS), were then analyzed
by psychologists, and the results were tabulated.
The results of Hooker's experiment yielded no
significant differences in answers on any of the three tests.
Because both groups' answers scored very similarly, she
concluded a zero correlation between social determinism of
sexuality.
As
a result of Hooker's finding, the APA removed homosexuality
from its Diagnostic and Statistical Manual of Psychological
Disorders in 1973. In
1975 it then released a public statement that homosexuality
was not a mental disorder.
In 1994, two decades later, the APA finally stated,
"...homosexuality is neither a mental illness nor a moral
depravity. It is
the way a portion of the population expresses human love and
sexuality" [2].
D.F.
Swaab conducted the next noteworthy experiment in 1990. This experiment became the first to document a physiological
difference in the anatomical structure of a gay man's brain.
Swaab found in his post-mortem examination of
homosexual males' brains that a portion of the hypothalamus of
the brain was structurally different than a heterosexual
brain. The hypothalamus is the portion of the human brain directly
related to sexual drive and function.
In the homosexual brains examined, a small portion of
the hypothalamus, termed the suprachiasmatic nucleus (SCN),
was found to be twice the size of its heterosexual counterpart
[2].
At
the same time, another scientist, Laura S. Allen made a
similar discovery in the hypothalamus as well.
She found that the anterior commissure (AC) of the
hypothalamus was also significantly larger in the homosexual
subjects than that of the heterosexuals [2].
Both Swaab's and Allen's results became a standing
ground for the biological argument on homosexuality.
The very fact that the AC and the SCN are not involved
in the regulation of sexual behavior makes it highly unlikely
that the size differences results from differences in sexual
behavior. Rather the size differences came prenatally during
sexual differentiation. The
size and shape of the human brain is determined biologically
and is impacted minutely, if at all by behavior of any
kind.
Simon
LeVay conducted another experiment regarding the hypothalamus
of the human brain in 1991.
LeVay, like Swaab and Allen also did a post-mortem
examination on human brains; however, he did his examinations
on patients who had died from AIDS-related illnesses. He examined 19 declared homosexual man, with a mean age of
38.2, 16 presumed heterosexual men, with a mean age of 42.8,
and 6 presumed heterosexual women, with a mean age of 41.2
[3]. LeVay discovered that within the hypothalamus, the third
interstitial notch of the anterior hypothalamus (INAH3) was
two to three times smaller in homosexual men then in
heterosexual men. The women examined also exhibited this phenomenon.
LeVay concluded the "homosexual and heterosexual
men differ in the central neuronal mechanisms that control
sexual behavior", and like Allen and Swaab, agreed that
this difference in anatomy was no product of upbringing or
environment, but rather prenatal cerebral development and
structural differentiation [2].
Another
line of testing done to support the biological perspective are
neuroendocrine studies. The
neuroendocrine viewpoint's basic hypothesis is that sexual
orientation is determined by the early levels (probably
prenatal) of androgen on relevant neural structures [7].
If highly exposed to these androgens, the fetus will
become masculinized, or attracted to females.
This research was conducted on rats at Stanford.
The adult female rats that received male-typical levels
of androgens sufficiently early in development exhibited male
symptoms of attraction. The
same was true in the reverse when applied to the male
subjects. The
female exposed to high levels of the hormone exhibited high
levels of aggression and sexual drive toward other females,
eventually trying to mount the other females in an act of
reproduction. In
the males, the subject who received deficient levels of
androgen became submissive in matters of sexual drive and
reproduction and were willing to receive the sexual act of the
other male rat [7].
A
popular route of experimentation in general psychology also
did not elude the biological argument.
Twin studies have become a highly debated area of
experimentation. Ernest
Kallman conducted the earliest twin study.
He found a 100% concordance between monozygotic (or
identical) twins (MZ), and only a 12% concordance for
dizygotic (or fraternal) twins (DZ).
Although discredited with methodological problems, the
early experiment paved the way for a much-publicized team to
conduct their twin studies.
J.
Michael Bailey and Richard Pillard also studied the gayness
between MZ twins, DZ twins, and non-related adopted brothers.
They examined how many of the sample population
examined were gay and how many were straight.
They found that 52% of MZ twins were both
self-identified homosexuals, 22% of DZ twins were so, and only
5% of non-related adopted brothers were so. This evidence, repeated and found to be true a second time,
showed to the biological camp that the more closely
genetically linked a pair is, the more likely they both are to
exhibit gay or straight tendencies.
Later experimenters found similar evidence in females.
One such scientist is Dean Hamer. Hamer examined the
possibility of homosexuality being an X-linked trait.
He examined the family trees of openly gay men, and
thought he saw a maternal link, leading him to investigate his
theory of X-linkage. He
took 40 DNA samples from homosexual men, and genetically
examined them. He
found that there was a 'remarkable concordance' for 5 genetic
markers on section of the X-Chromosome called Xq28 [2].
Hamer
hypothesized upon examining the family trees of the same men
that on each subject's mother's side, there were markedly
larger numbers of homosexual men, all stemming through the
maternal lineages. This
observation, along with his startling discovery on Xq28, led
his findings to be dubbed the "gay gene study".
The statistical probability of the 5 genetic markers on
Xq28 to have matched randomly was calculated to be 1/100,000
[2], lending even more support to his findings.
This
finding of a possible 'gay gene' prompts a look into two
evolutionary concepts, and how they are affected. The Superior Heterozygote Theory states the phenotypic
(actual) expression of homosexuality is the result of
homozygosity for recessive (non-expressed but present) genes
[11]. In
simplification, if the person's genetic code is heterozygotic
(one homosexual gene and one heterosexual gene), if the
homosexual allele (half of the genetic code) is the allele
passed on to the next generation, it will become the
phenotype. Heterozygotes
are only capable of being passed through to the next
generation by mothers (as the Y-chromosome is incapable of
heterozygosity), this again links homosexuality to
X-linkage.
While
all of this scientific experimentation and conclusion seems
evidentiary, sociobehaviorists are not convinced. This opposing point-of-view proposes that homosexuality is
the result of environmental factors, not biological ones. Most social theorists see childhood elements as the largest
contributing factors to homosexuality.
Often they examine childhood play patterns, early peer
interactions and relations, differences in parental behavior
toward male and female children, and the role of gender
constancy in the household [9].
The
social argument for homosexuality dates back to the ancient
Greeks. Aristophanes, in his Symposium investigates
homosexuality, although not termed as such, as a desire by men
to share a long-term fulfillment of the soul.
He believed that two souls are longing to be together,
and the sexual desire alone is not strong enough to create
homosexuality, but that the cultural environment allows or
forbids the relationship to occur [10].
In Greece is it well known that many men engaged in
same-sex relationships, however, these were not equal
relationships, they were older men to young boys going through
the transition to adulthood.
Two instances where the culture is a causative agent of
homosexual expression are in New Guinea and Crete.
In some tribes in New Guinea, young boys ages 8-15 are
inseminated daily by the young male warriors of the tribe.
In Crete, every adolescent boy undertook a homosexual
relationship as a rite of passage into manhood [10].
In these two instances, the homosexuality is accepted;
however, it can be argued that it is also forced, not a
natural expression.
Most
psychoanalytic theories, however, stress the role of parental
and family dynamics, not the society as a whole. Behaviorists believe that some sexual and gender
identification differences result from roles imposed by family
and friends upon children, such as the masculine and the
feminine stereotypes. Problems
with this are there is no evidence, social or biological, to
support that homosexual children were raised differently than
were the heterosexual children.
Also, with reinforcement of gender identification
norms, one would be led to logically deduce that all of the
stereotype reinforcement would ensure a heterosexual outcome
[7].
While
it is agreed that an element of gender ID is based on the
decision made by parents on how to raise the child, the other
element is formed with the development of language skills,
naming of sexual behaviors and the naming process related to
these behaviors [9]. Gender
ID is learned over time, and other contributions include the
frequency of parental interactions, tolerance of aggression
levels, and the vigor of play during childhood. In this,
another theory is acknowledged, the Parental Manipulation
Theory. This
theory is that one or both parents are able to neuter and
control offspring to promote their (the parent's) evolutionary
fitness, ensuring the passage of genes into the next
generation. By
selecting only heterosexual practices as acceptable, the
parents are attempting to promote their passage of genes [5].
However the Kin-Selection Theory contrasts this.
This theory states that it doesn't matter how the genes
are passed to the next generation, so long as they are passed
along. For
example, regardless of a homosexual outcome, the very similar
genetic makeup of siblings will still allow for the passage of
the family genetics along to the next generation [9].
Two
predominant social theorists on homosexuality are David
Halperin and Jean Foucault.
Although both social theorists, both have largely
contrasting ideas on the environmental contributions to the
formation of an individual's homosexuality.
Halperin believed in Planophysical theory.
This theory believes that homosexuality is a freak of
nature, an error. His
theory follows in the tradition of psychological theory on
this subject. Halperin
was a Freudian psychologist, and places stock in Freud's idea
that homosexuality is derived from a failure to resolve
Oedipal issues [10]. Although
Halperin has a large following from interest groups such as
Christian coalitions, his theory is
largely disrespected by the psychological community at large,
as it provides only a result, not a cause.
He fails to produce any scientific evidence.
He does, however, provide examples.
He postulates that a weak father and strong mother,
with an unresolved Oedipus complex will lead to a weak, and
then homosexual, son, because the mother has too strong of an
image, compared to the weak state of the father.
Psychologists argue that this same arrangement would
also possibly lead to a stronger son, striving for
compensation of his father's weakness.
Jean
Foucault argues, "...homosexuality became because we made
it so" [11]. Foucault
says that the category of homosexuality itself was only
created a mere one hundred years ago, after a German neologism
coined some twenty years later.
Foucault gives root to the social derivation of
homosexuality believing that homosexuality appeared as one of
the forms of sexuality, only "after it was transposed
from the practice of sodomy into a kind of interior androgyny,
a hermaphrodism of the soul" [10].
The theorists believe that the homosexual had been an
aberration, and had then become a species, justifying itself
with a new word.
Although
both theorists represent the major ideas of the
socioenviromental belief, there are three differences in the
two theories. The
first is based on the depth of desire.
Foucault believed that the depth of desire is only
sexual preference, that it is nothing more than superficial
tastes and preferences. Halperin
contrasts this with saying that homosexuality does go deeper
than superficial tastes, and that homosexuality is a
psychological condition, with much deeper roots than mere
sexual preference. The second major difference is that Foucault did not divide
people into categories. Halperin
acknowledged that there are three general categories of people
in respect to sexuality: heterosexual, gay men, and lesbians. Foucault groups gay men and lesbians into the all-inclusive
term of homosexual. The
third difference is that Halperin see homosexuality as a
symmetrical and equal relationship, Foucault believes that
historically, as far back as the Greeks, before the term was
coined, homosexuality has always been unequal, differences in
race, age, education and social status influencing the
'superficial' tastes and preferences of the men
influenced.
We
have examined many causes for homosexuality in the preceding
pages, both biological and social. And although an interesting topic of debate, no one theory or
experiment leads to a definitive answer.
Some believe that the characters found on Xq28 are the
Holy Grail of homosexuality research, the elusive 'gay gene'. Others may place stock in the theories of Foucault and
Halperin. Perhaps
Simon LeVay did reveal to us that anatomy is the key to
understanding the difference in sexual orientation.
Perhaps there is no one answer, that sexual
orientation, whether homosexual or heterosexual; gay,
straight, lesbian, or bisexual, all are a cause of a complex
interaction between environmental, cognitive, and anatomical
factors, shaping the individual at an early age.
WORKS
CITED
[1]
APA Online. “Answers
to Your Questions About Sexual Orientation and
Homosexuality”. Online.
11 April 2003. Available
http://www.apa.org/pubinfo/answers.html.
[2]
“Biological Basis for Homosexuality.” Online. 8 April
2003. Available
http://www.geocities.com/southbeach/boardwalk/7151/biobasis.html
[3]
Bull, James J. and Pease, Craig M. “Biological Correlates of
Being Gay” Online. 11 April 2003. Available http://www.utexas.edu/courses/bio301d/Topics/Gay/Text.html.
[4]
Fujita, Frank. “The
Nature-Nurture Controversy.” Online.
8 April 2003. Available http://www.iusb.edu/~ffujita/Documents/nn.html
[5]
Hoback, Wyatt. “Lecture
21. Sociality.” Online.
11 April 2003. Available http://www.unk.edu/acad/biology/hoback/2002bio470/470lecture21.htm.
[6]
Moberly, Elizabeth R. Homosexuality:
A New Christian Ethic.
James Clarke and Co.; Cambridge, MA,
1983.
[7]
Pillard, Richard. “NPR Letters on the Biological Basis of
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[8]
Sullivan, Andrew. Virtually
Normal: an Argument about Homosexuality.
Alfred A. Knopf; New York, NY, 1995.
[9]
Thompson and Devine. “Homosexuality:
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[10]
Thorp, John. “The Social Construction of Homosexuality.”
Online. 8 April
2003. Available http://www.fordham.edu/halsall/med/thorp.html
[11]
Taylor, Tim. “Current
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April 2003. Available http://www.dai.ed.ac.uk/homes/timt/
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