Myths and Misconceptions Dedicated to the
Preservation of the Family.
About Behavioral Genetics and Homosexuality
By Douglas A. Abbott, Ph.D.
n order to correctly of death. report homosexuality at a higher rate than
understand the genetic Now, what is a gene? A gene is a in the general population, then homosexu-
argument that homo- segment of DNA—with hundreds or ality must have a genetic component. The
sexuality is inborn, thousands of nucleotides—that appear to goal of such studies is to estimate, using
it is imperative to act together in some orchestrated man- correlational statistics, the genetic influ-
understand the basic ner. Genes act in two primary ways: they ence on homosexuality.
concepts of behavioral direct the manufacture of proteins, and The Holy Grail is the “heritability”
genetics. The nature- activate or deactivate other genes.5 quotient. Heritability is a big deal in
nurture interaction is often misunderstood For example, a boy may have inher- behavior genetics, but a concept that is
by the uneducated layman or the naïve ited genes for superior athletic ability in difficult for most people to understand,
non-scientist who misinterpret the typical the form of increased lung capacity or and a concept misrepresented in the me-
news headline that reads, “Gene X has more fast-twitch muscles. He could be a dia. It simply means the correlation of a
been found to cause Behavior Y.” Behav- great runner, swimmer or cyclist. Yet, his trait among relatives. “Heritability” is the
ioral Genetics (BG) is the study of genetic parents are poor, and he gets few chances proportion of phenotypic variation (in a
influences on human behavior. It is the population) that is attributable to genotyp-
study of “how genes, operating within ic variation (in a population). Said another
environments, connect to behavior.”1 way, “heritability describes the extent to
“Behavior” refers to “observable actions, These environmental which genetic differences among indi-
or even emotions and moods” and can be forces interact with genetic viduals in a population make a difference
“unconscious, automatic, or instinctual.”2 factors from the moment of phenotypically.”7 Sound confusing? It is to
In a broader sense, even “personality” is a most people!
behavior. conception until the time of Heritability is indicated by a numerical
death value that varies from 0 to 1. A herita-
Nature and Nurture bility quotient of 0 indicates no genetic
contribution to individual differences in
Work Together phenotype; while a quotient of 1 indicates
Behavioral genetics always acknowl- to engage in sports. Also, his parents don’t
watch sports or engage in sports them- the behavior (the phenotype) is completely
edges both environmental and genetic
selves. They prefer camping, hunting, and determined by genetic variations. For
influences on behavior—never assuming
fishing when they have the time and the example, suppose that in a family study,
“that one or the other is omnipotent.”3
money. As a teenager, the boy must work heritability for homosexuality was found
Employing probability statistics, research-
part-time and go to school. He has little to be .40. This means that 40 percent of
ers estimate the comparative contribution
time for extra-curricular activities. Thus, the variation in sexual preference among
of both genes and environment in shaping
he never runs the mile, swims the butter- this family group may be due to genetic
fly, or wins a triathlon! variation, and 60 percent of the variation
Next, we ask, what constitutes “envi-
in sexual preference may be due to envi-
ronment”? The environment is any non-
Studies of Genetic ronmental differences.
genetic influence, including internal bio-
Please note: Heritability estimates do
logical entities such as nutrients, bacteria, Influence on Homosexuality NOT indicate that for a specific person, 40
viruses, and medicines.4 Environment Now I turn attention to the matter
percent of his gayness is due to genet-
includes any forces that impinge upon the at hand: the supposed genetic basis for
ics and 60 percent is due to environment.
person (from outside) such as parent- homosexuality. Basically, three types of
Heritability estimates can only indicate
ing and family life, peers, the media, inquiries have been used to demonstrate
that there is probably something in the ge-
climate variations and natural disasters, the genetic basis for homosexuality:
netic pool of this sample at this time that
and disease and war. These environment family studies, twin studies and adoption
may increase the likelihood of a person (in
forces interact with genetic factors from studies.6 The simple idea behind all these
this small family group) becoming gay.
the moment of conception until the time studies is that if relatives of homosexuals
Identifying Inherited Factors are treated alike by teachers and peers, and Heritability estimates are correlations
in Particular Individuals are therefore more likely to share the same regardless of what statistical test is used.
Studies of twins (both identical and environment. Correlations cannot rule out the third
fraternal), and adoption studies are most variables problem: that there is something
often used to investigate heritability. A Data on Environmental else, not observed and measured, that is
typical twin study works this way. Identi- Influences is Lacking causing the correlation.
cal and fraternal twins, where at least one With all of these family studies, Let’s say that I do a heritability study
of the twins is homosexual, are recruited the critical limitation is the absence of for the “talent to succeed” gene. It’s an
through gay and lesbian publications, detailed environmental information such important gene. The gene would predict
websites, or gay support groups.8 The as family’s sexual values, the social and whether you will get a good education and
volunteer twins are asked to identify their political ideology of family members, their have a high paying job. I would survey
sexual preference, sexual fantasies, etc. exposure to the media, the occurrence all your families, nuclear and extended
The results usually show that if an identi- of mental illness in family members, the including your first cousins. I would prob-
cal twin is gay, his brother is very likely incidence of abuse and incest or neglect, ably find that a lot of people in your fami-
to be gay, with maybe a 40 to 50 percent and a detailed examination of the parent- ly system appear to have the “talent” gene,
chance. If a fraternal twin is gay, then his child relationships. In most of these family because the heritability quotient turns out
brother has about a 1 in 4 chance of being studies, environmental factors have not to be .72. Remarkable: what a strong ge-
gay. In a family with a gay biological been adequately measured, so one cannot netic effect! You are very lucky to be part
child, an adopted brother may only have of a gene pool that has a high incidence
a three to five percent chance of being of the “talent” gene. But of course no one
gay—which is about the incidence of It is reasonable to assume studies the heritability of good, healthy,
or positive traits, so we will never know if
male homosexuality in the general popu-
lation. The inference is then made that
that sexual behavior—in any you posses the amazing talent gene.
homosexuality must be genetic because and all of its manifestation—
the closer the blood tie (thus the more is directed by the activity of Nature and Nurture Together
genes in common) between brothers, the
more likely that a gay boy will have a gay
many, possibly hundreds of behavior—in any and assume that sexual
It is reasonable to
all of its manifesta-
brother. genes. tion—is directed by the activity of many,
The ideal heritability study is one possibly hundreds of genes. But the exact
involving identical twins that were and specific type of sexual expression is
separated early in life and raised in dif- rule out environment as an important con- also influenced by countless environmen-
ferent families. Then if you find a high tributor to homosexuality. This is the most tal forces that interact with the genes in
concordance (or agreement) rate between serious limitation of heritability studies. complex ways.12 Except for the rare physi-
these brothers reared apart, then we can Heritability quotients have other cal abnormalities, such as Huntington’s
assume that homosexuality is caused by limitations. Estimates are not constant Disease, there is no evidence at the present
genes. Yet even these studies have limita- numbers but can change over time and in time of a direct causative link between a
tions. First, there are very few (maybe different populations. Many large samples single gene and complex psycho-social
6-10) sibling pairs of homosexual boys are needed to obtain valid heritability esti- behavior such as sexual preference.13 This
reared apart reported in the literature. mates. This is seldom done. Heritability is is not my mere idiosyncratic opinion but
Replication is almost impossible. Second, a population parameter like the mean. The read any book on behavior genetics or
researchers provided little information on average height of a population tells you molecular biology, and the authors will
why and when the siblings were separated nothing about the tallness or shortness of unanimously agree that, at present, there is
and who actually raised the siblings. The any particular individual! Likewise a heri- no gay gene.14 For example:
sibling may have been separated for only tability quotient tells you nothing about Dr. Francis S. Collins (MD and PhD)
a few years and even raised by relatives. why a particular person is gay. A heritabil- head of The Human Genome Project has
For example, in many cases of IQ studies ity quotient cannot be used to predict who said:
done on twins, the separated twins were may become gay or lesbian. There is an inescapable component
raised by kin—divorced parents, aunts Another limitation of these studies of heritability to many human be-
and uncles, or grandparents—and the is the authorship. Most of this research havioral traits. For virtually none of
twins had occasional or frequent interac- has been done by gays that have a vested them is heredity ever close to predic-
tions.9 Thus, the psycho-social, economic, interest in the outcome. The fourth caveat tive…An area of particularly strong
and ideological environments of the is the use of biased samples. Volunteers public interest is the genetic basis of
“separated” twins may have been more from gay groups may only participate if homosexuality. Evidence [indicates]
similar than assumed. they have a gay brother or sister. Even gay that sexual orientation is genetically
Even if the twins are raised in the advocates such as J. Michael Bailey admit: influenced but not hardwired by DNA,
same home, “there is abundant evidence “If, for example, a gay twin who sees an and that whatever genes are involved
that the environments of MZ [monozy- advertisement for a [twin] study may be represent predispositions, not predeter-
gotic or identical twins] are very much less likely to call if his twin is heterosex- minations.15
more similar than those of DZs [dizygotic ual, this would cause concordance-depen- Baker, a behavioral psychologist,
or fraternal twins].”10 In other words, dent bias.”11 explains:
identical twins are often dressed alike, The last limitation is the fact that Most physical traits and conditions
play together more than other brothers, “correlation does not indicate causation.” such as height, blood pressure, weight
and digestive activity stem from many Evolutionary anthropologist Sarah as sexual preference are not determined by
genes that vary in activity depending Blaffer Hrdy adds: a single gene, but by a gene-environmental
on environmental contexts. The same Nature cannot be compartmentalized process involving possibly hundreds of
is true of all complex [psycho-social] from nurture, yet something about genes acting through complex environ-
behaviors. Each is affected by multiple human imaginations predisposed us to mental factors.22 Behavioral psycholo-
genes interacting with multiple envi- dichotomize the world that way…Com- gist, Baker, writes: “The fact is that so
ronmental influences…Unfortunately; plex behaviors like nurturing, espe- far, scientific research has not confirmed
many people have a different impres- cially when tied to even more complex any one-to-one correspondence between
sion. They think that a gene controls a emotions like “love,” are never either a gene and a [complex psycho-social] be-
behavioral trait. This is genetic deter- genetically predetermined or environ- havior. Behavior results from the activity
minism, the belief that the development mentally produced.18 of multiple genes amidst the influence of
of an organism is determined solely by In summary, there is no undisputed multiple environmental factors.”23 Figure
genetic factors. Genetic determinism is evidence that same-sex behavior is hard- 1 shows how complex and convoluted is
a false belief. It comes from misunder- wired in the brain. Genes are complex the interplay between genes, environment
standings of scientific research… The strands of DNA that through the processes and behavior.24
fact is that so far, scientific research of transcription and translation, direct If the reader is still unconvinced that
has not confirmed any one-to-one the synthesis of amino acids into larger scientists have not found the “gay gene,”
correspondence between a gene and a proteins that influence cell structure and let me share with you one final bit of
[complex] human behavior. Behavior functioning.19 Complex social activities knowledge about behavioral genetics.
results from the activity of multiple such as sexual behavior cannot be directly Suppose you could isolate a segment
genes amidst the influence of multiple traced to the activity of a single gene.20 of DNA that you thought was related to
environmental factors.16 Many uninformed people take a sim- homosexuality. You could then specify the
Two scientists, McInerney and Roth- plistic view of behavioral genetics: they exact, let’s say 183,000 base pairs, that
stein, who have worked on the Human believe that one gene controls and deter- make up this portion of DNA. The “gene”
Genome Project, caution us when inter- mines a specific behavior. This is true for a would look something like this sequence:
preting research on genetic “causes” of very few, abnormal physical conditions in- TA, GC, TA, TA, GC, CG, AT, AT, AT,
behavior: cluding Huntington’s disease, cystic fibro- GC, GC, CG, TA….. The letter A, T, G,
How do genes influence behavior? sis, PKU, and achondroplasia (Dwarfism). and C stand for the four nucleotides that
No single gene determines a particu- This fact has led some to believe that there make up DNA: adenine, thymine, guanine,
lar behavior. Behaviors are complex is an alcoholic gene, a manic-depression and cytosine. Now you get DNA samples
traits involving multiple genes that are gene, or a gay gene. However, “Genes do of other gay men and examine this exact
affected by a variety of other factors. not act as master puppeteers within us. 183,000 base-pair sequence on the same
This fact often gets overlooked in the They are chemical structures that control chromosome. You compare the sequencing
media report hyping scientific break- the production of proteins; thereby indi- of TA, CG, GC, and AT along the whole
throughs on gene function, and unfor- rectly affecting behavior…Genes do not length of the gay gene. Surprise: The
tunately, this can be very misleading to determine one’s destiny.”21 sequences from 10 gay men don’t nearly
the public.17 Complex psycho-social behaviors such match! Some portions are similar, but
Figure 1: Nature-Nurture Interaction
most are dissimilar. ronmental factors are usually not studied biological influences on sexual preference
But you don’t give up. You recruit the so the effects are unaccounted for. Fourth, or sexual orientation.”34 Gay advocates
brothers of the original 10 gay men. You there are obvious interpretation problems Parker and DeCecco conceded that “re-
code their nucleotides at the same foci because only about half of identical twins search into possible biological bases of
on the suspected gay gene. You find that reared in the same family have a gay sexual preference has failed to produce
the DNA sequences of the gay/non-gay brother. If genes determined homosexual- any conclusive evidence.”35
brothers are more similar than that of the ity, then both brothers should be gay. Fifth,
gay/gay men. In other words, the non-gay other twin studies have not supported their Genes + Environment
brothers’ DNA sequence is more similar claim of a strong genetic component to Genes or hormones may make it more
to their gay brothers than is the sequenc- homosexuality.29 likely that a person will display certain
ing of the gay men to each other! You are Dean Hamer and his colleagues ex- temperament characteristics or atypical
persistent so try once more. You recruit amined a small section of the X chromo- gender role behaviors. These outcomes
another 20 gay men and code their DNA. may make the child more vulnerable to
Again, you find that there is more dis- child trauma (e.g., sexual abuse, nega-
similarity in the sequences of base pairs The genetic theory of tive fathering, and rejection by same-sex
between the gay men than similarities.
Undaunted, you write another grant and
homosexuality rests on a peers). The child’s psycho-social sequelae
may, in turn, set up conditions where
keep looking. foundation of three seminal the child is more likely to consider the
Scientists have actually done what studies in the early 1990’s, homosexual option.36 Bancroft has stated
I have just described but with only few which all have serious that biological factors that may influence
inherited diseases like hemophilia.25 Hub- sexual orientation “need to be understood
bard concluded that most scientists believe methodological, sampling, as interacting with the effects of social and
that “base sequences can vary a great deal and interpretation problems. cognitive learning rather than having di-
without any change being apparent in the rect effects of their own.”37 Thus, genetic
corresponding trait.”26 That’s an amazing factor may indirectly influence sexual
fact and puts the crimp in anyone’s plan to some in the families of 40 gay men. In orientation, but there is no evidence of a
discover the elusive gay gene. a complicated pedigree analysis, Hamer direct casual link between a gay gene and
claims that homosexuality is transmitted homosexual behavior.
Critique of Past Research through the maternal side and is geneti- I like the analogy of gene-environment
The genetic theory of homosexual- cally linked to the X chromosome region interaction provided by Robert Plomin et.
ity rests on a foundation of three seminal known as Xq28.30 His conclusion has been al.:
studies in the early 1990’s, which all have criticized by several authors.31 If homo- A sailboat needs both sails [environ-
serious methodological, sampling, and sexuality were a simple Mendelian trait ment] and a hull [genes]. The ‘be-
interpretation problems. Simon LeVay (like eye color), then Hamer should have havior’ of a sailboat (speed, turning
dissected the brains of 19 gay men and found a higher incidence of homosexual- ability and direction) depends on the
supposedly 16 non-gay men and found, ity among brothers. There is no evidence design of its sails and the design of
on average, a slighter smaller area of the that the Xq28 section of the chromosome its hull. The aerodynamic shape of
hypothalamus (INAH-3) in the gay men. has anything to do with sexual behavior! the sails, their number and size, and
He then “suggests that sexual orienta- Hamer did not assess this genetic marker their positioning are important. The
tion has a biological substrate.”27 There on the heterosexual men in the sample to depth, width, length, and shape of the
are several major flaws with his research: see if they possessed it also. Rice, An- hull are also important. Obviously, for
(1) the sample was small, (2) the control derson, Risch and Ebers did a similar but sailboats, there can be no behavior
group was inappropriate, (3) there is no larger study and found no support for an without both sails and hull, but this
evidence that the INAH-3 part of the brain X-linked gene underlying male homosexu- does not restrict us from asking about
had anything to do with sexual preference, ality.32 Hamer’s study has never been rep- the independent contributions of sail
(4) AIDS could have caused the brain dif- licated. Thus, none of these studies proves design and hull design to the behavior
ferences, and (5) the study has never been a direct causation between a gene and the of sailboats…Behavior requires both
replicated. complex psychosocial behavior of sexual genes and environment.38
Michael Bailey and Richard Pillard preference.33 The more amazing point is Yet, even this example is flawed. The
concluded there must be a genetic cause to that all of these men—LeVay, Bailey, and missing factor in Plomin’s analogy is the
homosexuality because they found higher Hamer—readily admit that their research “captain” at the helm of the ship. That cap-
rates of homosexuality among identical does not prove there is a gay gene and that tain is “agency,” “free will,” and “choice”!
than fraternal twins and even less concor- environment is a major factor in homo- Regardless of sails (environmental factors)
dance (similarity) among adopted sib- sexuality! and hull design (genetic predispositions),
lings.28 These quantitative genetic studies Even advocates for a genetic explana- the captain can make moral decisions
have similar limitations. First, the samples tion of homosexuality, such as Szuchman, independent of both sails and hull. The
may be biased because researchers usu- concluded that the scientific evidence for captain may be constrained by genes and
ally recruit a volunteer sample from gay a biological cause of homosexual behav- environment—but he is not absolutely
publications and organizations. Second, ior is “remarkably flawed, such that no determined by them. Agency intervenes,
such studies require a large sample in unbiased view for or against many of these on many occasions, at various times and
order to make valid heritability estimates, factors [i.e., biogenetic causes] is pos- places, in the interplay between genes and
and samples are usually small. Third, envi- sible…We still have no good evidence of environment.
The British poet William Ernest 15. Collins, Francis S. (2006). The language
Henley (1849-1903), in his famous poem Douglas A. Abbott, is a professor of Child, of god, a scientist presents evidence for
“Invictus” (Latin for “unconquerable”) Youth & Family Studies at the University of belief. New York: Free Press.
Nebraska in Lincoln, NE. A longer version 16. Baker, C. (2004). Behavioral genetics: An
penned this famous line: “It matters not introduction to how genes and environ-
how strait the gate, how charged with pun- of this article was originally published by the
ments interact throught development to
ishment the scroll. I am the master of my National Association for Research and Therapy shape differences in mood, personality,
fate: I am the captain of my soul.” There is of Homosexuality (NARTH) on its web site and intelligence. New York: The American
clear evidence that many men and women at www.narth.com. It is reprinted here with Association for the Advancement of Sci-
are at the helm controlling their sexual permission from NARTH and the author. ence and the Hastings Center, pg. 17-18.
behavior and making choices regarding 17. McInerney, J., & Rothstein, J. (2007). What
is behavioral genetics? Retried online
sexual preference. July 5, 2007 from: http://www.ornl.gov.
Copyright 2007. North Carolina Family sci/techresources/Human_Genome/elsi/
Conclusion Policy Council. All Rights Reserved. behavior.shtml
I believe that the hypothetical evidence 18. From Hrdy’s 2000 book Mother Nature,
cited in Ridley, M. Nature via nurture:
for genetic determinism of homosexuality Endnotes Genes, experience, and what makes us hu-
is overstated and overrated. Most people 1. Baker, C. (2004). Behavioral genetics: An man. New York: HaperCollins, pg. 246.
do not have the knowledge to understand introduction to how genes and environ- 19. How genes work. (2007). Genetic Home
the research and are simply hoodwinked ments interact throught development to Reference, A Handbook on How Genes
by the pro-gay activists. It is obvious to shape differences in mood, personality, Work. Retrieved online July 6, 2007 from:
and intelligence. New York: The American
me, and to many others, that environmen- Association for the Advancement of Sci-
tal factors play the major role in same-sex geneswork.pdf; Schwartz, M., & Azar, M.
ence and the Hastings Center. Entire book (1981). Advanced cell biology. New York:
behavior. If this were not so how does one available free online at: http://www.aaas. Van Nostrand Reinhold.
explain the thousands of men and women org/spp/bgenes/publications.shtml, p. 17 20. Parens, E., Chapman, A, & Press, N.
who have left homosexuality? 2. Ibid., Baker, p. 2-3 (2006). Wrestling with behavioral genet-
Consider the recent example of Mi- 3. Plomin, R., DeFries, J., & McClearn, G. ics: science, ethics, and public conversa-
chael Glatze, the founder of Young Gay (1980). Behavioral genetics: a primer. San tion. Baltimore, MD: Johns Hopkins
Francisco, CA: W. H. Freeman, p. 374
American Magazine, a film producer, pro- 4. Op. Cit., Baker, C. (2004).
University Press; Pelle, S. (1995). “My
gay lecturer and author, and a well-recog- genes made me do it.” Psychology Today,
5. Op. Cit., Plomin, R., DeFries, J., & Mc- July/August, pp. 50-53 and 62-68; Rutter,
nized leader in the gay movement. At age Clearn, G. (1980). M. (2006). Genes and behavior nature-
14 he believed himself to be “gay,” but at 6. Lewontin, R. C., Rose, S., & Kamin, L. nurture interplay explained. Ames, IO:
age 30 he “seriously began to doubt” what (1984). Not in our genes. New York: Pan- Blackwell Publishing.
he was doing.39 He explains: theon Books, p. 213; also see Pattatucci, 21. Plomin, R., DeFries, J., & McClearn, G.
A. M. (1998). “Biopsychosicla interaction
Knowing no one who I could approach (1980). Behavioral genetics: a primer. San
and the development of sexual orienta- Francisco, CA: W. H. Freeman, p.13
with my questions and my doubts, I tion.” In C. Patterson and A. D’Augelli,
turned to God…It became clear to me 22. Rutter, M. (2006). Genes and behavior
Lesbian, gay, and bisexual identities in nature-nurture interplay explained. Ames,
that homosexuality prevents us from families, pp. 19-35. New York: Oxford IO: Blackwell Publishing
finding our true selves…I was leading University Press. 23. Op. Cit., Baker, C. (2004). pg. 18.
a movement of sin and corruption… 7. Op. Cit., Plomin, R., DeFries, J., & Mc- 24. Diagram adapted from Plomin, R., DeFries,
Now I know that homosexuality is lust Clearn, G. (1980). p. 224 J., & McClearn, G. (1980). Behavioral
8. Bailey, J. M., & Dawood, K. (1998).
and pornography wrapped into one. “Behavioral genetics, sexual orientation,
genetics: a primer. San Francisco, CA: W.
I’ll never let anybody try to convince H. Freeman, p. 7
and the family.” In C. Patterson and A. 25. Lippman, A. (1991). Prenatal genetic test-
me otherwise…Healing from the D’Augelli, Lesbian, gay, and bisexual ing and screening: Constructing need and
wounds caused by homosexuality is identities in families, pp. 3-21. New York: reinforcing inequities. American Journal
not easy—there’s little support. In my Oxford University Press. of Law and Medicine17, 15-50.
experience, coming out from under the 9. Lewontin, R. C., Rose, S., & Kamin, L. 26. Hubbard, R., & Wald, E. (1999). Explod-
influence of the homosexual mindset (1984). Not in our genes. New York: ing the gene myth. Boston, MA: Beacon
Pantheon Books. Press. See also: Gianelli, F. (1990). Hae-
was the most liberating, beautiful and 10. Ibid., p. 214
astonishing things I’ve ever expe- mophilia B: Data base of point mutations
11. Bailey, J. M., & Dawood, K. (1998). and short additions and deletions. Nucleic
rienced…I believe that all people, “Behavioral genetics, sexual orientation, Acid Research, 18, 4053-4059.
intrinsically know the truth. I believe and the family.” In C. Patterson and A. 27. Le Vay, S. (1991). “A difference in hypo-
that is why Christianity scares people D’Augelli, Lesbian, gay, and bisexual thalamic structure between heterosexual
so much. It reminds them of their identities in families, pp. 3-21. New York: and homosexual men.” Science, 253,
Oxford University Press.
conscience, which we all possess. 1034-1037.
12. Hubbard, R., & Wald, E. (1999). Explod- 28. Bailey, J. M., & Pillard, R. C. (1991). “A
Conscience tell us right from wrong ing the gene myth. Boston, MA: Beacon
and is a guide by which we can grow genetic study of male sexual orientation.”
Press; Ridley, M. (2003), Nature via nur- Archives of General Psychiatry, 48, 1089-
and become stronger and freer human ture: Genes, experience, and what makes 1095.
beings.40 us human. New York: HaperCollins 29. Hershberger, S. L. (1997). “A twin registry
In conclusion I believe that the genetic 13. Collins, Francis S. (2006). The language study of male and female sexual orienta-
evidence for homosexuality is just not of god, a scientist presents evidence for tion.” The Journal of Sex Research, 34,
belief. New York: Free Press.
there. It’s the values and politics of homo- 14. Lewontin, R. C., Rose, S., & Kamin, L.
sexuals and their supporters that is driving 30. Hamer, D. H., Hu, S., Magnuson, V. L., Hu,
(1984). Not in our genes. New York: N., & Pattatucci, A. (1993). “A linkage
the gay gene agenda, not good science. Pantheon Books. between DNA markers on the X chro-
mosome and male sexual orientations.”
Science, 261, 321-327.
31. Baron, M. (1993). Genetic linkage and
male homosexual orientations. British
Medical Journal, 307, 337-342.
32. Rice, G., Anderson, C, Risch, N., & Ebers,
G. (1999). “Male homosexuality: Absence
of linkage to micro-satellite markers at
Xq28.” Science, 284, 663-671.
33. Lasco, M., Jordan T, Edgar, M, Petito, C.,
& Byne, W. (2002). A lack of dimorphism
of sex or sexual orientation in the human
anterior commissure. Brain Research, 936,
34. Szuchman, L.T., & Muscarella, F. (2002).
Psychological perspectives on human
sexuality. New York: John Wiley & Sons,
35. Parker, D. A., & DeCecco, J. P. (1995).
“Sexual expression: A global perspective.”
Journal of Homosexuality, 28, 427-430.
36. Stein, E. (1999). The mismeasure of desire:
The science, theory, and ethics of sexual
orientation. New York, NY: Oxford Uni-
37. Bancroft, J. (1990). “Commentary: Biologi-
cal contributions to sexual orientation.”
In D. McWhirter, S. A. Sanders, and J. M.
Reinisch (Eds.), Homosexuality hetero-
sexuality concepts of sexual orientation,
pp. 101-111. New York, NY: Oxford
38. Plomin, R., DeFries, J., & McClearn, G.
(1980). Behavioral genetics: a primer. San
Francisco, CA: W. H. Freeman, p. 359.
39. Moore, A. “Gay-rights leader quits homo-
sexuality.” Posted on July 3, 2007 and
available on-line at: http://www.worldnet-
40. Ibid., pgs. 3-5.
Organized in 1992, the North Carolina Family Policy Council is a nonpartisan, nonprofit, research and education organization. Our goal is to serve as a
voice for families and traditional family values in the public policy arena. We are supported solely by private contributions which are tax deductible as
provided by law. Our mailing address is P.O. Box 20607, Raleigh, NC 27619. Phone: (919) 807-0800. Fax: (919) 807-0900. Web: www.ncfamily.org.
Findings is a publication of the North Carolina Family Policy Council which is intended to communicate research findings and perspectives on public
policy issues that affect the family. Nothing written here should be construed as necessarily reflecting the views of the North Carolina Family Policy
Council or as an attempt to aid or hinder the passage of any bill before Congress or the North Carolina General Assembly. Printed September 2007.