Homosexuality : Selected Studies
and Review of Possible Origins
Edith Fairman Cooper
Analyst in Social Science
Science Policy Research Division
April 15, 1993
HOMOSEXUALITY: SELECTED STUDIES AND REVIEW OF
The question about whether homosexuality is inherent or the result of
environmental influences and choice has been debated since at least the 19th
century . To date, scientific research has not explicitly proven which factor takes
precedence--inheritance or environment . Some researchers believe that a hard
line cannot be drawn between the two theories . Both factors might contribute
in some measure to the homosexual orientation . The door, however, has been
opened for further research .
During the 19th century, many members of the scientific community
studied the phenomenon and believed that the condition was inborn, could not
be "cured," and sufferers should be placed in asylums . This response ultimately
led to the concept that homosexuality is a form of degeneracy and an illness .
Until the 1970s, the majority of researchers presumed homosexuality was
a mental illness that could be "cured ." In 1973, the American Psychiatric
Association eliminated the term from its list of diagnostic mental illnesses . This
change eventually led to the current concept among most practitioners in the
mental health field, including psychiatrists, psychologists, and psychoanalysts
that homosexuality is not a mental illness .
The 1940s research of Alfred C . Kinsey and his associates about human
sexual behavior, brought to light many contradictions in what was previously
believed to be marked distinctions in sexual orientations . The Kinsey group
found that homosexual experience was more widespread and the sexual
experiences of many persons more varied than expected . Therefore, defining
homosexuality is not always precise . No one really knows the percentage of
individuals who openly or privately consider themselves to be homosexual . The
current estimates for homosexuals in the general population range between a
low of two percent to a high of nine percent . Results of a recent survey of
sexual practices and attitudes of men in the Nation revealed that 2 .3 percent
reported homosexual experiences, while 1 .1 percent claimed to be exclusively
Numerous research efforts have been conducted to see if there is a
biological cause(s) for homosexuality . One method employed has been the use
of twins in attempting to determine the role that inheritance and environment
play in causing homosexual behavior . To date, researchers still do not clearly
understand how genes contribute to determining a person's sexual orientation .
Recent neurobiological research revealed size differences in the
hypothalamus region of the brain in homosexual and heterosexual men .
Because of some inconsistencies and other shortcomings, experts warn that
caution should be used when considering implications of the research .
Discrepancies and exceptions also exist in studies attempting to determine
the impact of environmental factors on eventual homosexual orientation .
TABLE OF CONTENTS
DEFINING SEXUAL ORIENTATION AND HOMOSEXUALITY . . . . 3
U.S . INCIDENCE OF HOMOSEXUALITY 6
CAUSES OF HOMOSEXUALITY
Genetic Component : Twin Studies 8
General Concerns About Twin Studies 12
Studies of Twins Reared Apart
Genetic Component : Familial Studies 13
Neurobiological Component : Brain Differences 14
Sexual and Gender Identity Development 17
Childhood Gender Identity
Adolescent Gender Identity
The Father-Son Relationship
The Mother-Son Relationship
Theories Related To Some Societal Beliefs And Attitudes 24
CONCLUSIONS AND POLICY CONCERNS 26
APPENDIX A . Types of Homosexual Behavior of Some
Men and Women
HOMOSEXUALITY: SELECTED STUDIES AND
REVIEW OF POSSIBLE ORIGINS
Although the practice of homosexuality existed in ancient times, the term
"homosexual" was not coined until 1869 by Karoly Maria Benkert, a Hungarian
writer who published a pamphlet on the subject under the pseudonym,
Kertbeny, according to Vern L . Bullough in his book, Homosexuality: A
History .' Benkert considered the phenomenon a result of nature, endowing at
birth certain males and females with the homosexual urge that placed them in,
what he termed, a sexual bondage, creating in them a direct horror of the
opposite sex, and the impossibility of suppressing feelings for persons of their
own sex . The 19th century was referred to as an age of science . Therefore, it
was not long before the medical component of the scientific community began
to study this phenomenon .
Carl Westphal, a professor of psychiatry in Berlin, was the first physician
to study homosexuality more scientifically . In 1869, he published the case
history of one of his female patients who had exhibited homosexual
characteristics from an early age . Westphal concluded that this behavior was
innate (existing from birth) instead of acquired and therefore could not be
considered morally evil . Additionally, Westphal noted that although elements
of a nervous disorder were present, they did not indicate insanity . He referred
to homosexuality as a "contrary sexual feeling ." This led to much discussion and
publications within the medical community . The term "inverted sexual instinct"
became the term of choice . It was well into the 20th century before the word
"homosexuality" took pre-eminence .
As time progressed, the question concerning whether homosexuality,
although considered to be innate, could be "cured" was explored . Jean Martin
Charcot, a well-known 19th century French neurologist, and his colleagues tried
to "cure" homosexuality by using hypnosis . After only modest success, they
referred to the phenomenon as a "constitutional nervous weakness due to
hereditary degeneration ." Another French physician, Paul Moreau, contended
that homosexuality was like a sixth sense, "a genital sense," that he believed
could suffer some form of injury like the other senses (seeing, hearing, touching,
etc .) without harming other mental functions . He referred to this behavior as
"an hereditary taint" that was like a predisposition to perversion encouraged by
certain environmental factors, such as age, poverty, temperament, and others .
The only solution, he felt, other than imprisonment, was to place such sufferers
'Bullough, Vern L . Homosexuality: A History. New York, Garland STPM Press, 1979 . p .196 .
This book was used primarily as a reference for the historical information about homosexuality
discussed in the introductory section of this report .
into asylums to be cared for, since the condition probably could not be "cured ."
This response to homosexuality, Bullough stated, ultimately led to the concept
of degeneracy, which subsequently influenced society's thinking on this matter .
Sigmund Freud and his associates believed that the condition resulted from
a distortion in the natural development which leads to heterosexuality, and
should not be classed as "degenerate ."' Expanding upon Freud's ideas, many
psychoanalysts believed that homosexuality was environmental resulting from
early childhood experiences, rather than inborn, and could be treated through
psychotherapeutic intervention. 3
Also, most psychoanalysts defined
homosexuality as a pathological (caused by disease) diversion from the
heterosexual "norm ."
This view gradually became the consensus among
professional practitioners in the United States .
In 1954, psychologist Evelyn Hooker received a grant from the National
Institute of Mental Health to study homosexuality . Her research effort to
determine whether homosexual men were less psychologically adjusted than
heterosexual men did not reveal any significant differences between the two
groups . This finding indicated, she believed, that homosexuality was not
equated with maladjustment, nor was there a particular homosexual
personality.' Her investigation contributed to the subsequent changes that
occurred in the scientific community's viewpoint that homosexuality resulted
from a mental dysfunction.
Until the 1970s, most scientific research focused on homosexuality as a
mental illness .' This view of the phenomenon as a "sickness," also implied that
it could be "cured ." In 1973, the American Psychiatric Association (APA), after
several years of debate, removed the term from its official list of psychiatric
disorders, The Diagnostic and Statistical Manual of Mental Disorders (DSM-II) .
By 1986, any specific reference to homosexuality as a mental disturbance was
completely eliminated from the APA's DSM-III-R (third edition, revised) . (Under
the category, "Psychosexual Disorders Not Otherwise Specified," there is listed
"persistent and marked distress about one's sexual orientation .") In spite of
these changes, one author reports that in the 1980s, "psychoanalysts remained
steadfastly committed to the pathological perspective ."6 Currently, according
to one respected observer, the majority of practitioners in various disciplines
2Bayer, Ronald . Homosexuality and American Psychiatry: The Politics of Diagnosis .
Princeton, New Jersey, Princeton University Press, 1987 . p. 22 .
'Ibid ., p . 121.
4 Facts That Liberated the Gay Community . Psychology Today, Dec . 1975. p . 52 .
°Garnets, Linda, and Douglas C . Kimmel . Lesbian and Gay Male Dimensions in the
Psychological Study of Human Diversity. In Psychological Perspectives on Human Diversity in
America. Jacqueline D . Goodchilds (ed .) Washington, D .C ., American Psychological Association,
1991, p . 144 .
6Bayer, Homosexuality and American Psychiatry, p. 191.
within the mental health field, be it psychiatrist, psychologist, or psychoanalyst,
do not consider homosexuality as a mental illness . 7
Whether homosexuality is an inborn trait that cannot be altered or results
from environmental influences (such as dysfunctional family relationships and
other factors) implying that it can be "cured," has been debated since the 19th
century. How society perceives the causes of homosexuality can clearly
influence how homosexuals are treated by society and its institutions .
This report discusses various selected scientific research studies that have
explored possible causes of homosexuality . Some investigations examining
biological factors are described, as well as studies that consider possible
environmental influences .
Various problems in defining sexual orientation and homosexuality exist .
Before research studies are discussed, definitional concerns are reviewed along
with some of the issues related to determining the national incidence of
The terms "gay" and "lesbian" are not used in this report to refer to
homosexual men and women . According to Linda Garnets and Douglas Kimmel,
a psychotherapist and psychologist, respectively, who specialize in work with gay
and lesbian individuals, the terms "gay" and "lesbian" involve "a life-style that
implies some degree of self-awareness and identification with the larger lesbian
and gay male community." Contrastingly, the word, "homosexuality" may
involve sexual acts without a gay or lesbian life-style or self-identification . 8
Because of these differences, only the term homosexuality is used to denote male
or female sexual orientations . Furthermore, male homosexuals primarily are
discussed, unless specifically indicated otherwise . This is because, to date, far
more scientific information is available concerning male homosexuality than
DEFINING SEXUAL ORIENTATION AND HOMOSEXUALITY
Distinct questions arise when trying to define sexual orientation and thus,
homosexuality . This section discusses the basic definitions of sexual orientation
and homosexuality and describes some of the uncertainties that exist .
As used here, the term "sexual orientation" means an individual's preferred
adult sexual behavior--specifically heterosexual, homosexual, or bisexual .' A
7 Discussed during a telephone conversation with a spokesman in the Library of the American
Psychiatric Association on March 29, 1993 .
8 Garnets and Kimmel, Lesbian and Gay Male Dimensions, p . 145.
° Campbell, Robert J . Psychiatric Dictionary, 6th ed . New York, Oxford University Press,
1989 . p. 673 .
homosexual has been defined as a person with a "sexual orientation
characterized by erotic attraction to others of the same sex ; feelings of love,
emotional attachment, or sexual attraction to persons of one's own gender
and/or sexual behavior with a person of the same sex ." A heterosexual is an
individual with a sexual desire directed toward persons of the opposite sex . A
bisexual is a person who, after adolescence, consciously feels, thinks, and
alternately reacts by thoughts and feelings, erotically, and/or orgastically to
both, persons of the same and of the opposite sex ."
Many experts in the field of sexuality consider sexual orientation to be
complex because it involves a person's self-identification, behavior, fantasies,
emotional attachments, and current relationship status ." These different
factors can contribute to a "blurring" in lines of distinction between the sexual
orientations as identified and described above .
Historically, most professionals in mental health fields viewed
homosexuality and heterosexuality as dichotomous, which means that they were
divided into two mutually exclusive or contradictory groups . This position,
however, was challenged by the findings of Alfred C . Kinsey and his associates
Wardell B . Pomeroy, and Clyde E . Martin in their 1948 and 1953 reports, Sexual
Behavior in the Human Male, and Sexual Behavior in the Human Female,
respectively . The Kinsey group's research documented human sexual behavior
patterns and discovered that the homosexual experience was more widespread
than was previously known, and that engaging in homosexual acts did not
necessarily make an individual a homosexual ." The Kinsey group estimated
that nearly 50 percent of all people in the United States had experienced some
level of homosexual sensual feelings, and many had acted on those feelings ."
Such experiences usually occurred during adolescence, particularly early
adolescence with the first encounter around age 14 . 14
The Kinsey group's findings brought about extensive controversy over the
definition of a homosexual when the researchers concluded that millions of
10Ibid ., p . 328, 323, 98 .
Garnets and Kimmel, Lesbian and Gay Male Dimensions, p . 146-
Sanders, Stephanie A., June Machover Reinisch, and David P . McWhirter .
Homosexuality/Heterosexuality: An Overview. In McWhirter, David P ., Stephanie A. Sanders,
and June Machover Reinisch, eds . Homosexuality/Heterosexuality: Concepts of Sexual Orientation .
New York, Oxford University Press, 1990. p . xxi-xxiii.
13Voeller, Bruce . Some Uses and Abuses of the Kinsey Scale
. In McWhirter, David P .,
Stephanie A. Sanders, and June Machover Reinisch. Homosexuality/Heterosexuality
Sexual Orientation . New York, Oxford University Press, 1990 . p . 32.
14 Gebhard, Paul H . Incidence of Overt Homosexuality in the United States and Western
Europe. In U.S Dept . of Health, Education, and Welfare . Alcohol, Drug Abuse, and Mental
Health Admin . National Institute of Mental Health Task Force on Homosexuality : Final Report
and Background Papers . John M . Livingood, ed. U.S . Govt . Print . Off., 1976. p. 25. DHEW
Publication No. (ADM) 76-357.
people in the Nation at some time engaged in homosexual activity, or
experienced varying degrees of homosexual erotic feelings . The group's findings
suggested that a large percentage of persons surveyed for their study could not
be placed into either exclusively heterosexual or exclusively homosexual
categories as judged by the Kinsey scale .
The Kinsey scale ranges from zero to six (0-6) and indicates the degree of
a person's sexual orientation between "Exclusively heterosexual with no
homosexual" at point zero (0) ; to point one (1), "Predominantly heterosexual,
only incidentally homosexual ;" point two (2), "Predominantly heterosexual, but
more than incidentally homosexual ;" point three (3), "Equally heterosexual and
homosexual ;" point four (4), "Predominantly homosexual, but more than
incidentally heterosexual ;" point five (5), "Predominantly homosexual, but
incidentally heterosexual ;" to point six (6), "Exclusively homosexual .""
The Kinsey group found that there are people in the population who have
exclusively heterosexual experiences, both "overtly" (by physical sexual contact)
and "psychically" (by thoughts and feelings only), as well as exclusively
homosexual experiences, both overtly and psychically. The record also showed,
however, that a large number of persons had combined homosexual and
heterosexual histories both overtly and psychically . Some of these individuals
had predominately heterosexual experiences, and some had predominately
homosexual experiences . Also, there were some who had equal amounts of both
types of experiences ." More recent data have not refuted this theory . 17
The controversy regarding the Kinsey group's findings and the pioneering
research of psychologist Evelyn Hooker, contributed to the reconsideration of
the nature of homosexuality (whether this sexual orientation indicates problems
in psychological adjustment) and finally to the change in its classification by the
American Psychiatric Association as a mental illness . 18
dictionary currently states that, "[h]eterosexuality and homosexuality are not
dichotomous . For both heterosexual and homosexual persons, early sexual
behavior (in childhood or adolescence) may be congruent or incongruent with
the direction of adult sexual expression ." 19 This means that early sexual
activity, whether heterosexual or homosexual in nature, may not necessarily
determine the direction of an individual's sexual expression in adulthood .
1DKinsey, Alfred C ., Wardell B . Pomeroy, and Clyde E . Martin . Sexual Behavior in the Human
Male, Philadelphia, W. B . Saunders Co., 1948. p . 638-639.
16 Ibid ., p . 639.
"Bell, Alan P ., and Martin S . Weinberg. Homosexualities: A Study of Diversity Among Men
and Women . New York, Simon and Schuster, 1978 . p . 53-61 . This study appears to be the most
recent major study that essentially expanded Kinsey's research effort with male and female
homosexuals that included minorities, as well as whites in the study .
18Ibid., p. 196 .
19Campbell, Psychiatric Dictionary, p . 328 .
Some analysts suggest that there are different "types" of homosexuals .
Because of societal pressures or inner conflicts, a person's sexual behavior might
be inhibited and he/she may not engage in "overt" homosexual acts but be a
homosexual . Also, there are some people who are referred to as "latent"
homosexuals who have an unrecognized attraction to the same sex, or may have
recognized such feelings, but have not openly expressed them ." Therefore,
some investigators believe that there is no such thing as the homosexual or the
heterosexual . They state that the basis of sexual orientation "must always be
highly qualified ." Furthermore, homosexual individuals differ from one another
just as heterosexuals differ based on sexual experience and social and
psychological adjustment ." (See Appendix A for brief descriptions of various
types of homosexual behaviors .)
U.S. INCIDENCE OF HOMOSEXUALITY
No one knows the exact number or percentage of individuals in the United
States who openly or privately consider themselves to be homosexual . The
Kinsey group reported from the 1948 study that 10 percent of the white male
population was more or less exclusively homosexual for at least three years
between the ages of 16 and 55 . Also, the group determined that four percent of
the white males interviewed for the study (out of about 5 .000) had been
exclusively homosexual throughout their lives since adolescence up to the time
Although these data are still used by many analysts, they have been
attacked as misleading and distorted . Several researchers reanalyzed Kinsey's
data and tabulated an incidence of homosexuality that ranged between a low of
two percent to a high of nine percent . These studies often differed in definitions
used for homosexuals and research techniques employed ."
20Ibid ., p . 328 .
Bell and Weinberg, Homosexualities, p . 23, 219.
22 Kinsey, et al ., Sexual Behavior in the Human Male, p . 651 .
Fay, Robert E ., Charles F . Turner, Albert D. Massen, and John H . Gagnon . Prevalence and
Patterns of Same-Gender Sexual Contact Among Men . Science, v. 243, Jan . 20, 1989 . p . 338-348Gebhard, Incidence of Overt Homosexuality in the United States and Western Europe, p .
Hunt, Morton . Sexual Behavior in the 1970s . Chicago, A Playboy Press Book, 1974 . p . 313 .
Rogers, Susan M., and Charles F . Turner. Male-Male Sexual Contact in the U .S .A :
Findings from Five Sample Surveys, 1970-1990 . The Journal of Sex Research, v. 28, no . 4, Nov .
1991 . p . 491 .
Smith, Tom W . Adult Sexual Behavior in 1989: Number of Partners, Frequency of
Intercourse and Risk of AIDS . Family Planning Perspectives, v . 23, no . 3, May/June 1991 . p . 102 .
Recently, the Wall Street Journal published an article which claimed that
the Mosey group's 10 percent figure was discovered to be in error when
statisticians began tracking AIDS cases during the mid-1980s . The New York
City health department used the 10 percent Kinssy figure with known HIV
infection rates among homosexual men to estimate the size of the city's HIVinfected male homosexual population . The health department estimated that
the number was 250,000, and the total number of homosexual and bisexual men
in the city's population was between 400,000 to 500,000, respectively . When
HN-infected men were surveyed, it was discovered that the number in the city's
population had been overestimated . This led to the belief that the Kinsey 10
percent prevalence figure for homosexuals in the general population was too
A $1 .8 million four-year study was conducted and recently reported by
researchers at the Battelle Human Affairs Research Center in Seattle,
Washington, surveying sexual behaviors and attitudes of men in the Nation
between the ages of 20 and 39 . Findings from personal interviews revealed that
2 .3 percent reported having homosexual experiences, while 1 .1 percent claimed
to be exclusively homosexual .25
CAUSES OF HOMOSEXUALITY
Several theories about the causes of homosexuality exist . Recently, the
most prominent scientific hypotheses focus on possible inherent 26 origins and
environmental influences that might determine some individuals' eventual
homosexual orientation . This section describes research that has been
conducted attempting to substantiate these theories .
There have been many studies done over the years concerning the
possibility of biological causes of or proclivities toward homosexuality . The
question that has occupied such studies is whether or not there are biological
differences in heterosexuals and homosexuals . The discussions below focus on
research that is currently receiving prominent public attention--behavioral
genetic research 27 conducted through studies of twins, attempting to determine
24Muir, J . Gordon . Homosexuals and the 10% Fallacy . The Wall Street Journal, Mar . 31,
1993 . p . A14 .
2'Rensberger, Boyce . Sex Survey : What Men Do and How Often They Do It . Washington
Post, Apr . 15, 1993 . p. Al, A16 .
26Implanted by Nature, Inborn . Dorland's Illustrated Medical Dictionary, 27th ed .
Philadelphia, W. B . Saunders Co ., 1988 . p. 838.
genetics is a recent scientific discipline with the premise that genetics influence
complex human behavior . Human behavioral genetic research (as opposed to nonhuman animal
if there is a genetic component for homosexual behavior, and neurobiological
investigations examining possible brain differences in homosexuals and
heterosexuals . After the twin studies are discussed, other hereditary research
that explores whether a trait for homosexuality can be transmitted genetically
in families is mentioned briefly . The neurobiological research is then presented .
Genetic Component: Twin Studies
Several biology-related theories have been suggested to explain
In the 19th century, some investigators believed that
homosexuals were no more responsible for their sexual orientation than they
were for their eye or hair color . This conclusion was drawn because the subjects
they studied were in mental hospitals and had several inherited physical and
mental defects . Consequently, experts surmised that homosexuality also was an
inherited defect ." This idea, however, was never proven .
In 1952, a genetic theory that seemed to have proof was presented by Franz
Kallmann29 , a geneticist, who studied identical (monozygotic) and fraternal
(dizygotic) twins in one of the largest such studies conducted at that time . In
studying 85 pairs of twins, at least one of which was exclusively
predominantly homosexual, Kallmann found evidence that homosexuality was
more likely to occur in both identical twins than in both fraternal twins . Since
identical twins develop from one fertilized egg that has split and become two
individuals, each twin has identical chromosomal inherited traits .
homosexuality was caused solely by heredity, then if one twin is homosexual, the
other would be homosexual . Contrastingly, because fraternal twins develop
from two separate fertilized eggs and are not genetically identical, 30 the
probability of both of them being homosexual is much less than for identical
twins, according to this view .
Kallmann reported that he had found a 100 percent concordance 31 rate in
the identical twins studied . This meant that both identical twins in each set
studied were homosexuals .' The results of Kallmann's research presents
27 ( . . .
studies) explore the role of inheritance in behavior by relying on family, adoption, and twin
designs . (Robert Plomin . The Role of Inheritance in Behavior . Science, v . 248, Apr. 13, 1990 .
28Hunt, Morton . Gay: What You Should Know About Homosexuality .
Farrar/Straus/Giroux, 1977 . p . 33 .
29 Kallmann, Franz J .
Comparative Twin Study on the Genetic Aspects of Male
Homosexuality . The Journal of Nervous and Mental Disease, v . 115, no . 4, Apr . 1952. p. 283-298.
Bermont, Gordon, and Julian M . Davidson . Biological Bases of Sexual Behavior . New York,
Harper and Row, Publishers, 1974 . p . 228.
31 Concordance means agreement . "In statistics, used primarily in twin studies to refer to the
proportion of a representative sample of affected twins whose co-twins are or will be similarly
affected ." Campbell, Psychiatric Dictionary, p . 144 .
32Kallmann, Comparative Twin Study on the Genetic Aspects of Male Homosexuality, p . 296 .
evidence that seems to indicate, at first impression, that genetic factors are
relevant in the origin of homosexuality ."
's study has been criticized for shortcomings in his research
methods, including (1) he used homosexual subjects who were mainly from
correctional and psychiatric institutions, (2) he failed to explain his procedure
to determine whether the twins were identical or fraternal, and (3) his finding
that the identical twins studied had a 100 percent concordance rate for
homosexuality was overestimated . 34 Some researchers' review of these results
indicated that the rate was probably closer to 50 percent ." Kallmann's results
and conclusions on the genetic basis of homosexuality have been questioned
because of the overestimation .
Another investigator has criticized Kallmann's findings
alternative explanations listed below for Kallmann's results : 36
and sugges s
Identical twins grow up in the same environment and basically have
the same life experiences . The only way the heredity theory could be
proven is if identical twins were separated at birth, reared apart, and
they both were homosexual . None of Kallmann's twins were reared
Heredity does not completely control human behavior in any other
area, so probably would not in the area of sex . Therefore, it seems to
follow that sexual preference would be in part or in large part, learned
and influenced by experiences ; and
Many social scientists believe that heredity gives some individuals the
general tendency to become a homosexual . The person might not
become one, but has a strong tendency to become one .
Since Kallmann's 1952 study, several researchers have explored the
heredity theory of homosexuality by studying pairs of identical and fraternal
male twins . Some agreed with Kallmann's conclusion that the probability of
both identical twins being homosexual is higher than the probability of both
fraternal twins being homosexual . 37 Other studies, however, showed findings
Heston, L. L ., and James Shields . Homosexuality in Twins : A Family Study and a Registry
Study. Archives of General Psychiatry, v . 18, Feb . 1968 . p. 150 .
Bailey, J. Michael, and Richard C . Pillard . A Genetic Study of Male Sexual Orientation .
Archives of General Psychiatry, v . 48, Dec . 1991 . p . 1090 .
Pillard, Poumadere, and Carretta . Is Homosexuality Familial? p . 470 .
36Hunt, Gay. What You Should Know About Homosexuality, p . 34-35 .
37Heston and Shields, Homosexuality in Twins, p . 159.
contrary to this concept ." One such study is reviewed below . Investigations
of twins reared apart also have been conducted and will be discussed below .
In a 1976 twin study, conducted by psychiatrist Bernard Zuger, results did
not show concordance, but discordance (i .e ., one twin was homosexual and the
other heterosexual) among identical twins for homosexuality . 39 Zuger studied
one identical twin pair that showed early childhood gender role differences with
one boy exhibiting "feminine" characteristics and the other "masculine ." He
concluded that factors other than genetic ones may have been operating either
before, during or immediately after the twins' birth, as well as familial
environmental influences that contributed to this dichotomy of sexual
orientation in the twins . Also, he surmised that there might have been
congenital 40 differences in development other than genetic .
however, that this finding did not support possible environmental family
influences as the cause of homosexuality in the one twin, because they had
grown up in the same environment .
A 1991 study by J . Michael Bailey and Richard C . Pillard (a psychologist at
Northwestern University in Evanston, Illinois, and psychiatrist at the Boston
University School of Medicine, respectively) entitled, "A Genetic Study of Male
Sexual Orientation" 41 , has been described as more thorough and considerably
larger than previous studies . These experts concluded that genetics play a
significant role in the origin of homosexuality, thus supporting Kallmann's
theory . The study found, however, that Kallmann overestimated his data on
twin concordance ." After interviewing 161 homosexual men, the researchers
sent questionnaires to twins and adoptive brothers--56 identical twins, 54
fraternal twins, and 57 adoptive brothers . Through analyzing questionnaire
responses, they discovered that 52 percent of identical twins were either
homosexual or bisexual (Kallmann indicated 100 percent concordance), compared
with 22 percent of the fraternal twins, and 11 percent of the adoptive brothers .
Therefore, the research indicated that it is more likely for both identical twins
to be homosexuals or bisexuals than for either fraternal twins or adoptive
brothers . Similarly, the probability is greater for both fraternal twins to be
homosexual or bisexual than for adoptive brothers ."
"Eight investigations are mentioned in Bernard Zuger's study, that is discussed in this section
of the report, which discovered identical twins where one was homosexual and the other
heterosexual . This finding disproved Kallmann's theory .
39Zuger, Bernard . Monozygotic Twins Discordant for Homosexuality : Report of a Pair and
Significance of the Phenomenon . Comprehensive Psychiatry, v . 17, no . 5, Sept./Oct . 1976 . p . 661669 .
attribute or anomaly possessed and manifested by an individual since birth . Campbell,
Psychiatric Dictionary, p . 149 .
41Bailey and Pillard, A Genetic Study of Male Sexual Orientation, p . 1089-1096 .
lbid ., p . 1094 .
A significant inconsistency in this study involved the perceived rate of
homosexuality among non-twin biological brothers of the participants . The twin
participants reported what they believed to be the sexual orientation of their
non-twin brothers (who were not directly surveyed) . Out of 142 non-twin
brothers, 13 (9 .2 percent) were thought to be homosexual . This percentage was
lower than what was found for the adoptive brothers who are not, of course
biologically related. Hypothetically, if a significant genetic component was
evident, then the non-twin siblings would have had a greater probability of
being homosexual than the adoptive brothers . Bailey and Pillard stated that the
9 .2 percentage rate is considerably less than would be expected when compared
with other similar research that has been done in twin studies .
emphasized the desirability of verifying this finding of lower than expected rates
of homosexuality in non-twin brothers of homosexual twin subjects .
Bailey and Pillard concluded that "genetic factors are important in
determining individual differences in sexual orientation, and the rates of
homosexuality in different types of relatives are consistent with some genetic
influence ."44 These findings, however, do not clarify the magnitude of the
influence of genes on sexual orientation, which is referred to as the "heritability
estimate ." A heritability estimate could not be accurately determined because
the base rate of homosexuality in the general U .S . population is necessary to
compute such an estimate . Currently, there is no consensus regarding the
general population's homosexuality percentage rate . Although many analysts
believe the Kinsey data estimating the percentage of homosexuals in the general
population are distorted, and several reanalyzed the Kinsey data and suggested
lower estimates, Bailey and Pillard used what they feel are the most common
figures--the Kinsey group's low estimate of about four percent and a high
estimate of 10 percent . Using these population figures, they assessed that the
influence of genes on sexual orientation falls somewhere between the range of
30 to 70 percent, which is significant when contrasted with environmental
Generally speaking, scientists still do not understand how genes influence
an individual's sexual orientation . Simon LeVay, who has done extensive
research concerning differences in homosexual and heterosexual brains
(discussed below) has hypothesized that genes could affect the area of the brain
(hypothalamus) where he found differences . On the other hand, genes could be
the source of a biological characteristic that makes people treat others a certain
way. Bailey and Pillard theorized that about 30 to 70 percent of sexual
orientation differences may be attributed to genes, and LeVay believes, as do
many other experts, that other factors must significantly contribute in
determining one's sexual orientation ." Bailey feels that "the strongest non-
Ibid ., p . 1093 .
46Adler, Tina. Study Links Genes to Sexual Orientation . APA Monitor, v . 23, no . 2, Feb . 1992 .
p. 13 .
genetic influence on sexua o
that fetuses are exposed to ."
ation is biological, specifically the hormones
is theory is briefly discussed below .
In a study reported in 1993, Bailey, Pillard and associates" used the same
research strategy to examine genetic influences on female homosexuality . The
researchers reasoned that if genetic factors exist for homosexuality, they are
probably different for female homosexual orientation than those possibly
contributing to a male homosexual orientation . They predicted, however, that
the homosexuality rate would be higher for identical twins than fraternal and
would be lowest for adopted sisters .
Subjects were recruited through advertisements placed in lesbian-related
publications in several cities across the Nation . Out of a total of 115 female
homosexual identical and fraternal twins recruited, 107 pairs of twins were
used--71 identical and 37 fraternal . Also, 35 adoptive sisters participated .
Similar to the male homosexual twin study, the researchers discovered that 48
percent of the identical twin pairs, 16 percent of the fraternal twin pairs, and
six percent of the adoptive sisters were homosexuals .
The analysts stated that "[a]lthough we found evidence that female
orientation is at least somewhat heritable, the question of what, precisely, is
inherited remains ." 49 Bailey and Pillard expressed concerns about the validity
of the findings because of the method used to recruit participants, which they
felt could cause the results to be misleading. They suggested that the use of
twin registries for future sexual orientation studies would eliminate this
particular research bias . The most significant difference in the female study and
the previous male study was that far more relevant research statistics are
available for the males than for the females . There is a dearth of genetic data
on female homosexuals .
General Concerns About Twin Studies
Several concerns about Bailey and Pillard's male twin study and twin
studies in general have been reported . One psychologist observed that such
studies do not prove that any behavioral trait is heritable . Twin studies, he felt,
proved nothing concerning the gene versus environment argument . He observed
that identical twins share many more experiences than other siblings and are
more inclined to be similar in all areas 50
Bailey, J . Michael, Richard C . Pillard, Michael C . Neale, and Yvonne Agyei . Heritable
Factors Influence Sexual Orientation in Women . Archives of General Psychiatry, v . 50, Mar . 1993 .
"Ibid ., p . 221 .
50Adler, Study Links Genes to Sexual Orientation, p . 13 .
Other reported problems with twin studies include : (1) findings may be
unapplicable to the general population because of the unique characteristics of
individuals who are twins ; (2) most of these studies get participants by
advertising in gay publications, which does not guarantee a representative
sample ; and (3) when the studies actually are conducted, it is sometimes difficult
to score individuals as being homosexual or heterosexual ."
Studies of Twins Reared Apart
Leonard Heston, a psychiatrist at the University of Washington in Tacoma,
who has conducted several male homosexual twin studies, made the observation
about the difficulty of scoring individuals as homosexual or heterosexual . He
noted that in one of his studies conducted with a pair of identical twins who had
been reared apart, one twin who had been raised in the city was clearly
homosexual . The other had been raised on a farm, gotten married, and had
children . Between the ages of 16 and 22, however, the married twin had
experienced an affair with an older man . Heston surmised that if the married
twin had grown up in an environment where homosexuality was more common,
he might have maintained the homosexual relationship ." This case, however,
was just one situation studied . Heston has done other studies of twins raised
apart . 53 As a result of his research and others, Heston concluded that both
genetic and environmental factors contribute to homosexuality in twins . 54
Genetic Component : Familial Studies
A family study concerning sexual orientation has provided evidence that
homosexuality is biological, according to Richard Pillard and James Weinrich
(both of the Boston University Medical Center) in their research report,
"Evidence of Familial Nature of Male Homosexuality ." 55 Using a family study
method (interviewing certain family members about the sexual orientation of
their siblings), Pillard and Weinrich recruited and interviewed 51 predominantly
homosexual and 50 predominantly heterosexual men (referred to as index
subjects) who provided information about the sexual orientation of their siblings
(115 sisters and 123 brothers) . 56 The siblings were interviewed as well and
53Eckert, Elks D ., Thomas J . Bouchard, Joseph Bohlen, and Leonard L . Heston.
Homosexuality in Monozygotic Twins Reared Apart . British Journal of Psychiatry, v . 148, 1986.
p. 412-425 .
54Heston and Shields, Homosexuality in Twins, p . 159 .
55Pillard and Weinrich, Evidence of Familial Nature of ale Homosexuality . Archives of
General Psychiatry, v . 43, Aug . 1986, p . 808-812 .
a6Fourteen of these siblings were half-siblings, and three were adopted . On average, the
homosexual index subjects had more brothers than the heterosexual index subjects .
surveyed through a questionnaire regarding their sexual orientation, which
verified the accuracy of the information received from the index subjects . Only
the information obtained directly from the siblings was counted .
It was discovered that there was a four percent incidence of homosexuality
among the brothers of the heterosexual men canvassed, as would be predicted
given a national prevalence percentage for homosexuality (Pillard and Weinrich
used Kinsey's four percent figure for the general population) . However, 22
percent of brothers of the predominately homosexual men were found to be
either bisexual or homosexual, which is higher than the national population
average for homosexuality .
This 22 percent figure might actually be
underestimated because younger siblings also were used . Siblings under the age
of 20 might not yet have considered a sexual orientation label for themselves,
or might not have been willing to share that information with researchers .
Therefore, Pillard and Weinrich surmise that the 22 percent might be on the low
side, but probably by only a small amount . This is because some respondents
who rated as "predominantly heterosexual, only incidentally homosexual," which
is level "one" on the Kinsey scale, might later admit information that would
place them higher in the Kinsey rating toward the homosexual orientation . A
lowering of a person's Kinsey rating, they observed, over his/her life span is very
The investigators stated that the results should not be taken to imply that
male homosexuality might necessarily run in families because of genetic or
hormonal reasons . On the contrary, they concluded that environmental causes
seemed dominant . The participants frequently suggested that they believed an
overprotective mother and a detached father caused a son to be susceptible to
a homosexual orientation . Pillard and Weinrich results indicated a combination
of environmental and biologic causes for homosexuality .
Pillard and Weinrich felt that their findings were strongly based and are
supported by informal polls taken at some of their lectures before homosexual
audiences . First, by asking for a count of all men with brothers, then all men
with at least one homosexual brother, they speculated that about 25 percent of
those who raised their hand for the first count kept it up for the second . If 25
percent is correct, they believed that this reflected two things about the familial
theory of homosexuality : (1) "most homosexual men would not have any
homosexual brothers," and (2) "homosexuality in pairs of brothers would be
common enough that any male member of the homosexual community could
easily come up with examples drawn from among his acquaintances ." This
means, Pillard and Weinrich state, that such an occurrence is uncommon, but
far from rare, and widely suspected by many homosexuals themselves .
Neurobiological Component : Brain Differences
Simon LeVay, a neuroscientist at the Salk Institute in San Diego,
California, discovered that two small groups of nerve cells in the anterior
hypothalamus of the brain (the region that is involved in the regulation of
sexual behavior) were significantly larger in heterosexual men than women .
Also, they were more than twice as large in heterosexual men than in
homosexual men . 57 These two groups of specialized nerve tissue, LeVay
surmised, could be involved in generating male-typical sexual behavior correlated
with sexual orientation . Furthermore, he speculated that one or the other of
these groups of nerve tissue was large in persons sexually oriented toward
women (which are heterosexual men and homosexual women) and smaller in
persons sexually oriented toward men (which are heterosexual women and
homosexual men) .
These findings, LeVay believes, suggest that sexual
orientation could have a biological connection .
LeVay measured the specialized nerve tissue from 41 subjects at routine
autopsies of individuals . Eighteen were homosexual men and one bisexual man
(for a total of 19 subjects), all of whom had died from acquired
immunodeficiency syndrome (AIDS) complications ; 16 subjects were presumed
to be heterosexual males, six who had died from AIDS, and 10 from other
causes ; Six subjects were presumed to be heterosexual women, one died of AIDS
and five from other causes . All were near the same age--a mean age of 38 .2 for
homosexual men ; 42 .8 for the heterosexual men ; and 41 .2 for the heterosexual
women . Brain tissue from deceased homosexual women was not available .
Therefore, only the hypothesis regarding the sexual orientation of men could be
The researcher noted several problems with using brain tissue from
deceased homosexuals who died of AIDS . They are :
(1) Brain tissue from homosexual women is not available
because they have not been as affected by the AIDS epidemic
as homosexual men have . Therefore, the theory that the
specialized nerve tissue is larger in homosexual women than
in heterosexual cannot be explored;
(2) The small size of the specialized nerve tissue in homosexual
men could be the result of AIDS complications and not
sexual orientation .
Until tissue becomes available of
homosexual men dying from other causes, the possibility that
the small size of the specialized nerve tissue reflects the
result of disease peculiar to homosexual AIDS patients
cannot be excluded ; and
(3) The inability to obtain detailed information about the
sexuality of the diseased men, who as AIDS patients often
are characterized as having had numerous sexual partners,
limits the ability to make correlations between brain
structure and the noted differences in the sexual practices of
homosexual and heterosexual populations .
57LeVay, Simon . A Difference in Hypothalamic Structure Between Heterosexual and
Homosexual Men- Science, v . 253, Aug . 30, 1991 . p . 1034 .
In addition to these problems, LeVay also noted the existence of two
exceptions in the samples used : (1) presumed heterosexual men with small
specialized nerve tissue ; and (2) presumed homosexual men with larger
specialized nerve tissue . These situations suggested the possibility that the size
of the specialized nerve tissue may not be the only determinant of sexual
orientation . These exceptions also could be the result of assigning subjects to
the wrong groups .
In spite of these shortcomings, LeVay states that his discovery of the
differences in the size of the specialized nerve tissue in heterosexual and
homosexual men indicates that sexual orientation is "amenable to study at the
biological level and . . . opens the door to studies of neurotransmitters or receptors
that might be involved in regulating this aspect of personality ."
LeVay's research, as yet, has not been substantiated . Other investigators
state that speculation regarding the implications of the research should be made
cautiously . One reason that confirmation of this research is considered very
necessary is because controversy and contradiction always has surrounded
sexual dimorphism (combining qualities of two kinds of individuals) studies .
Brain structures are very difficult to see clearly in tissue slices, authorities
report, and researchers debate what is the most reliable measure of the size of
the specialized nerve tissue, whether by volume measurements, which LeVay
used, or by actual cell counts . 58
Prior to LeVay's study, Richard Swaab, a neuroscientist at the Netherlands
Institute for Brain Research in Amsterdam, found that the section of the brain
that controls daily rhythms, the suprachiasmatic nucleus (SCN), is twice as large
in homosexual men than in the brains of heterosexuals . LeVay observed that
the SCN does not play a role in sexual behavior . It might, however, be affected
by the same factors that cause homosexuality but probably not likely to be part
of the cause . 59
Sandra J . Witelson and her colleagues at McMaster University who have
studied sex hormones and brain development in rats, have hypothesized that
differing levels of testosterone, the sex hormone that stimulates the development
of masculine characteristics, 60 possibly could influence the development of the
part of the brain LeVay studied . Witelson discovered that the development of
the anterior hypothalamus in rats depends on testosterone levels before and
immediately after birth. In fact, it was observed that when male rats were
castrated at birth, the production of testosterone decreased and the region in the
anterior hypothalamus that is associated with sexual behavior was smaller than
58Barinaga, Marcia . Is Homosexuality Biological? Science, v . 253, Aug. 30, 1991 . p . 957 .
60Testosterone is a male sex hormone produced mainly in the testicles . The Book of Health :
A Medical Encyclopedia for Everyone . (3rd ed_) Randolph L . Clark, and Russell W. Cumley, eds.
New York, Van Nostrand Reinhold Co ., 1973 . p . 968 .
expected when compared with non-castrated male rats . In contrast, when female
rats were injected with testosterone, the same region in the anterior
hypothalamus was observed to be larger than in non-injected female rats . When
these altered rats reached adulthood, the males showed more "female" sexual
behavior while the females showed more "male" sexual behavior .
Many scientists search for comparable findings in humans . Witelson and
associates have found that homosexual males and females show a left-hand
preference in many tasks . Scientific research that examined people with
abnormal sex-hormone levels suggest that handedness is a brain feature that can
be influenced by sex hormones during brain development . Therefore, Witelson
and colleagues surmise that there might be irregular brain organization in
homosexuals also caused by irregular sex hormone levels .
Further research is needed regarding all of these theories, since most
findings are inconclusive and many areas remain uncertain .
This section of the report will examine behavioral and environmental
theories about the causes of homosexuality . Some investigators believe that past
experiences of a large number of male homosexuals add support to the idea that
homosexuality is biological . They also indicate, however, that environmental
factors play a strong part in the eventual adherence to the atypical sexual
orientation . How early a child and/or adolescent identifies himself as "different"
is discussed, as well as the role that some researchers believe parents play in
influencing their child or adolescent's future sexual orientation . In addition,
information is included that reviews survey results about some causative
theories that many people in society believe are true about the origin of
homosexuality . These findings are listed along with a researcher's analyses of
the theories .
Examining the literature for this section of the report revealed that there
a striking dearth of behavioral research studies investigating female
Sexual and Gender Identity Development
"Sexual identity" is sometimes used interchangeably with "gender identity ."
Some investigators, however, make distinctions in their definitions . Sexual
identity is biologically determined and identifies a person as either anatomically
male or female . Gender identity is considered behavioral noting the inner
conviction that one belongs to one sex and not the other ." An extension of
this concept is "gender role," which refers to culturally fixed behaviors and
61Barinaga, Is Homosexuality Biological? p. 957 .
62Wiedeman, George H . Homosexuality, A Survey . Journal of the American Psychoanalytic
Association, v . 22, no . 3, 1974 . p. 663.
appearances that differentiate between masculinity and femininity .
researcher includes these two definitions for anatomical identity and gender role
as components that comprise sexual identity, but also includes a third, sexual
orientation . This expert believes that all of these components can contribute to
an individual's gender identity . 63 This report uses gender identity to refer to
this developmental phase .
Childhood Gender Identity
Young boys who grow up to become ho osexuals usually have been
characterized as having exhibited various "feminine" behaviors as children .
There are exceptions . A minority of homosexual adult males report a lack of
early "feminine" behaviors, and having childhood characteristics no different
from other boys who grew up to a heterosexual orientation ."
A large number of homosexual men, however, report feeling "different" from
other boys early in childhood . Many of them indicate that homosexual feelings
were always there . Most report, however, that such feelings began between the
ages of eight and 13 or 14 years . 65 Others have expressed memories of erotic
feelings, usually toward their fathers, as early as ages four or five years ."
This period of development coincides with what is referred to as the Oedipal
complex stage in boys who have a heterosexual orientation when, according to
Freud's theory, boys erotically desire their mothers and have feelings of rivalry
and hostility toward their fathers ." Prehomosexual boys often display what
has been termed an inverted Oedipus complex where just the opposite occurs ."
The feelings that they have for their fathers, according to one expert,
initially causes them to feel "different" from other boys their age . In the
Freudian analysis, as boys with a heterosexual orientation usually imitate the
characteristics of the father in order to attract the mother, prehomosexual boys
often display the characteristics of the mother in order to attract the father .
Such patterns of display are labeled by many in U .S . society as "feminine" and
are considered to be gender atypical for four, five, or six-year-old boys . These
Green, Richard . The "SISSY BOY SYNDROME" and the Development of Homosexuality .
New Haven, Yale University Press, 1987 . p. 6.
Saghir, Marcel T., and Eli Robins . Male and Female Homosexuality : A Comprehensive
Investigation . Baltimore, Williams & Wilkins Co ., 1973 . p . 30 .
6oIsay, Richard A. Being Homosexual :
Farrar/Straus/Giroux, 1989. p . 23 .
Gay Men and Their
Ibid., p. 29 .
67Atkinson, Rita L ., Richard C . Atkinson, Edward
Smith, and Ernest R . Hilgard .
Introduction to Psychology . San Diego, Harcourt Brace Jovanovich, Publishers, 1987 . p . 474 .
68 Campbell, Psychiatric Dictionary, p . 494 .
"feminine" characteristics may include
relative lack of aggressiveness, and
greater shows of compassion and sensitivity than most other boys of those ages
display . Many times, these characteristics persist into adulthood, and are
recalled by several homosexual men as contributing to secretiveness, isolation,
and unhappiness in later childhood years . 9
Several research studies comparing the childhoods of adult homosexual
males with adult heterosexual males have found that most of their subject
prehomosexual boys exhibited "feminine" behaviors, which led to teasing by their
peers and being labeled as "sissies ." Many adult homosexuals reported similar
childhood experiences of having no male friends, avoidance of rough "boys"'
games, and playing mostly with girls . A large number remembered a consistent
desire to become a girl or a woman before they became adults . Some even crossdressed ." "Childhood gender nonconformity," an investigator found, was more
strongly related to adult homosexuality than any other variable in an interview
study of 600 homosexual men and 300 heterosexual men .
Adolescent Gender Identity
One writer has noted that many psychoanalysts regard the period of
adolescence as an opportunity for "homosexually inclined" boys to have another
chance to put aside these inclinations . Because of the stigma that is attached
to boys who display "feminine" characteristics, a deliberate effort usually is made
during adolescence to lose many of these traits acquired during childhood and
have gender role behavior conform to anatomy .' These youths may further
this effort by experimenting with heterosexuality much like some heterosexually
inclined youth, which the Mosey group discovered, experiment with
homosexuality during this developmental period . The cited studies indicate,
however, that the homosexually inclined youths usually continue to maintain
a predominantly homosexual fantasy life and impulses .
Gender identity continues to develop in prehomosexual boys in the midst
of feeling guilty because of sexual feelings and impulses that are "different" from
their peers and family members who are exclusively heterosexual . Their selfesteem in most cases continues to be damaged because of previous childhood
labelings and rejections of other boys, and the labeling of themselves as
Many times such youths try to convince themselves that these feelings will
disappear and eventually be replaced by the proper sexual desire some time in
69 Isay, Being Homosexual, p . 29-30 .
70 Green, The "SISSY BOY SYNDROME," p . 15 .
Ibid ., p. 11 .
72Isay, Being Homosexual, p . 20 .
731bid ., p. 4S.
the future . Because of this belief, these individuals do not acknowledge that
they are homosexual . One researcher states that usually because of negative
childhood experiences and the desire to fulfill heterosexual societal expectations,
a large number of such adolescents suppress or deny their sexual orientation .
Furthermore, this investigator has found that usually these individuals do not
acknowledge that they are homosexuals until they have an erotic experience
that cannot be denied, which will make them "suddenly" aware of their true
sexual orientation .' In contrast, some youths have a more gradual realization .
Usually this awareness becomes evident because of the type of erotic fantasies
they have and eventually, actual overt homosexual experiences they have in
middle or late adolescence ."
Much of society has placed the cause of homosexuality primarily at the
parents' door step . Most people who believe that parents are responsible feel
that homosexuality occurs because of a child's experiences within his/her
immediate surroundings . Homosexuality has been connected with broken
homes, unhappy childhoods, and poor relationships with parents . Of course,
most individuals who grow up in such environments do not become
homosexuals . The way a person reacts to a negative environment might
determine what methods are used to substitute or make-up for these type of
The well-known environmental theory regarding the cause of homosexuality
is that a child grows up in a household with an aggressive, overprotective,
domineering mother and a passive, weak, and sometimes absent or emotionally
distant father . 77
Some researchers believe that homosexuality is a
developmental problem that results from early conflicts between a father and
son . They argue that a strong mother's influence can be a factor that
undermines a father-son relationship and cripples a boy's self-reliance and
gender development . A boy fails to dis-identify himself with his mother,
experiences conflicts with his father (if one is in the home) and does not
internalize the male gender identity . The failure to identify with the male
gender alienates the father, as well as childhood male peers ." Even though
the mother's role is influential, other research indicates that the breakdown in
74Ibid ., p . 50, and Henckne, Joel D . Conceptualizations of Homosexual Behavior Which
Preclude Homosexual Self-Labeling. Journal of Homosexuality, v . 9, no . 4, Summer 1984. p . 53.
751say, Being Homosexual, p . 56 .
76Ibrahim, Azmy I
. The Home Situation and the Homosexual . The Journal of Sex Research,
v. 12, no . 4, Nov. 1976 . p . 263, 275.
Green, The "SISSY BOY SYNDROME," p . 51 .
78 Nicolosi, Joseph. Reparative Therapy of Male Homosexuality. Northvale, New Jersey, Jason
Aronson, Inc ., 1991 . p . 77, xvi .
the father-son relationship may be the more i o
development of homosexuality ."
The Father-Son Relationship
Since the mother-son relationship typically develops because of her
nurturing and care, the son's identifying with the "second other," his father, is
considered to be most important for his normal masculine development . Freud
and other psychoanalysts expressed the opinion that it is important for a father
to be available and supportive in order for his son to develop gender identity .
According to this theory, the father must be a dominant force within the home
if the young child is to identify with him ; it is crucial that a strong father-son
relationship takes place . This additional developmental task of identifying with
their fathers that heterosexual boys have to undergo has been perceived as
difficult by some theorists and they believe this extra step, unnecessary for
heterosexual girls, explains why there is a notably higher incidence of male
homosexuality compared to female . 80
Some analysts believe that gender identity receptiveness is most critical
during the second half of the second year of life . It is thought that during this
time a boy is most likely to decisively identify himself as male upon realizing
that he is separate and different from his mother and is like his father . He then
exhibits a special interest in his father and wants to grow and become like him .
Research indicates that if the father is warm and accepting toward his son, a
relationship develops, the father mirrors and affirms the boy's maleness, and the
boy dis-identifies with the mother and becomes masculine 81
It is also during this period of development that many experts believe that
the father has to influence the son's dis-identification with his mother by
showing him that he can maintain a close but independent relationship with
her . This reinforces and clarifies his separateness and differentness from his
mother . The triangular relationship with parents--mother-father-son--is where
some investigators feel the breakdown occurs in a homosexual's family
background . The typical, or even "stereotypic," situation seems to occur with an
abnormally close relationship between a mother and son, and a father who is
distant from both of them .82
79Tbid ., p . 80 .
80 Greenson, Ralph R. Dis-identifying From Mother : Its Special Importance for the Boy . The
International Journal of Psycho-Analysis, v . 49, Parts 2-3, 1968 . p. 370 .
81Abelin, Ernst L . The Role of the Father in Core Gender Identity and in Psychosexual
Differentiation . In Selma Kramer, moderator, and Robert C . Prall, reporter. The Role of the
Father in the Preoedipal Years . Journal of the American Psychoanalytic Association, v . 26, 1978 .
p . 148.
82Nicolosi, Reparative Therapy of Male Homosexuality, p. 28.
One writer states that such a relationship does not have to continue if the
mother and father work together to help the son shift identification from the
mother to the father . Some mothers might not assist in this endeavor, he notes,
but a dominant, nurturing father could counteract her influences .
Contrastingly, if the father is unloving and difficult, a mother who is less
emotionally available to the son when he voices his complaints about the father,
might help the son learn to tolerate the frustrations of having a difficult
father ." Most authorities recognize, however, the central importance of the
father developing masculinity in the son . 84
Similarly, it is widely believed that if the father is absent because of death
or divorce, the presence of a male figure--grandfather, uncle, older brother,
neighbor--is important in helping a young boy develop maleness . There are
reported cases, 86 however, where the heterosexual father regularly and
positively interacted with the son, but the son grew up to embrace a homosexual
orientation . In another situation studied, a boy grew up without a father, had
limited contact with other males during his first two or three years of life, but
was a masculine boy who grew up to embrace a heterosexual orientation . This
investigator, because of many exceptions to the rule, doubts "that socialization
homosexuality :" 86
Some might conclude that the examples in the preceding paragraph support
the biological theory that homosexuality is innate . Upon investigation, however,
this conclusion is questionable . The same investigator discussed a case with
twins ." One was initially homosexual but later became bisexual, while the
other was initially heterosexual but later also became bisexual . Their parents
raised one to be more feminine (always with the mother)S8 and the other more
masculine (always with the father) . Additionally, the more masculine twin was
named for the father, which seemed to influence later identification patterns and
sexual role . They were known as "Mom's Boy" and "Dad's Boy ." Initially,
neither chose to be with the particular parent selected for them . The father was
less pleasant to the son who was cared for by his mother, and this son later
"Ibid ., p . 29 .
Green, The "SISSY BOY SYNDROME," p . 385 .
"Ibid ., p . 384 .
&7Ibid., p. 322-352 .
"This twin had a physical illness at three years of age which required hospitalization. The
mother spent most of the time with him, while the father interacted with the other . Because of
the son's physical problem with his arm, the father did not "roughhouse" with him, but
encouraged him to stay with his mother and help her in the house with the chores_ Also, the ill
boy interacted with his younger sister . His "feminine" traits were noticed at age four .
is father . Eventually, "Mom's Boy" chose
acknowledged that he was afraid o
to be with her because of the harsh treatment of his father .
It appears that different nurturing and socializing methods from early
childhood years contributed to the twins' later initial sexual orientations . The
twins' initial sexual orientations, the researcher found, differed no more than
in other "feminine" and "masculine" type boys studied . He reasoned that this
was the case because of the "constraining influence of their common genetics ."
In other words, because they were twins, and had the same genetic make-up,
their common genes limited the impact of their different childhood experiences
on their later erotic behaviors . The initially homosexual twin later married, had
relationships with a few men on the side, but preferred women for a love
The initially heterosexual twin later developed an ongoing
homosexual relationship for monetary purposes, while being engaged to marry
a woman . The expert concluded :
That genetics does not account entirely for gender-role behavior is
demonstrated by the twins' different activities in childhood . That
genetics does not account entirely for sexual partner preference is
demonstrated by the twins' different patterns of adolescent and adult
erotic behavior . And the greater degree of homosexual orientation in
the previously "feminine" twin demonstrates the influence of early
gender-role behavior on later sexual orientation . 89
The Mother-Son Relationship
As previously noted, many investigators have found that very close motherson relationships occurred in the early childhoods of many homosexuals . A
researcher has observed that frequently a mother who lacks a warm relationship
with her husband, uses the son to substitute for the emotional absence of the
husband . On the other hand, if a loving bond exists between the father and
mother, this provides a model male-female relationship for the son, as well as
security for the mother who will not feel the need to maintain an overly
intimate relationship with her son . 90
According to some analysts, if there is a consistent miscommunication or
hostility between the mother and father, which results in regular arguments and
fighting, and a son sympathizes and identifies with the mother's hurts and at
the same time does not have a close attachment with the father, the son might
disassociate himself with the male figure and view masculinity as brutal and
insensitive . Eventually, the son might decide he does not want to be like the
father, vows not to be like him, begins to identify more with the mother, and
S9Green, The "SISSY BOY SYNDROME," p . 352 .
90Nicolosi, Reparative Therapy of Male Homosexuality, p . 82-83 .
does not take on the male role . This type of mother-son interaction might
contribute to later homosexual behavior of the son . 91
Exceptions to the usual close mother-son attachments are evident as well .
Sociology professor Azmy Ibrahim in his study, "The Home Situation and the
Homosexual," 92 revealed that out of the 31 homosexuals he interviewed, just
as many (40 percent) had negative relationships with their mothers, as those
who reported negative relationships with their fathers . Some complained that
their mothers were emotionally cold toward them and they could not
communicate with them . Also, some stated that they were afraid of their
mothers, which might have led to an eventual fear of all women . Ibrahim
hypothesized that this situation might have caused these particular boys to
dislike women and decide to confine themselves to men . He concluded that the
theory that homosexuality results from a strong identification with the mother
should be re-examined .
Theories Related To Some Societal Beliefs And Attitudes
In 1970, the Institute for Sex Research, at Indiana University, founded by
Kinsey and now referred to as the Mosey Institute for Research in Sex, Gender,
and Reproduction, conducted an extensive national survey through a grant from
the National Institute of Mental Health (NIMH) . This survey attempted to
examine the sexual norms and experiences of adults in the Nation, as well as
their moral judgments about certain sexual activities .
More than 3,000
individuals were interviewed and results incorporated in a book, entitled, Sex
and Morality in the United States : An Empirical Enquiry Under the Auspices
of the Kinsey Institute ." Homosexuality was a topic examined to assess societal
attitudes and stereotypes .
A section on "Causes and "Cures" of Homosexuality"was included under the
general topic, "The Social Reaction Toward Homosexuality." Participants were
asked whether they felt that some lay and professional theories about the causes
of homosexuality were true for most homosexuals . Some of the popular causal
beliefs and the percentages of persons who felt they were true are presented
below . Also, analysis of these beliefs, as presented by Morton Hunt 94 is
included with each theory .
., p . 83 .
92Ibrahim, The Home Situation and the Homosexual, p . 263-282 .
93 12assen, Colin J . Williams, and Eugene E
. Levitt . Sex and Morality in the U.S . : An
Empirical Enquiry Under the Auspices of theKinseyInstitute. Middletown,Connecticut, Wesleyan
University Press, 1989 . 462 p"Hunt, Gay: What You Should Know About Homosexuality, p . 29-33, 40.
[Y]oung homosexuals became that way because of older homosexuals ;
About 43 percent believed this theory accounted for more
than half of all homosexuals .
This idea was termed "seduction" by Hunt . He states that only one out of
four homosexuals in different studies attribute seduction by an older
homosexual as the reason for their homosexuality . Psychologist, C . A . Tripp has
found that usually the "victim" of a seduction was inclined toward homosexuality
already . Therefore, the seduction probably triggered what would have
eventually developed . 95
Most homosexuals are products of "how their parents raised them" ;
Almost 40 percent believed that this reason was the cause,
and 14 percent felt this applied to all homosexuals .
Some homosexual men have stated that they feel their parents were
responsible for their sexual orientation . Either a strong mother who wanted a
girl treated the boy like a girl and taught him "girlish" instead of "boyish" ways,
or a girl's parents wanted a boy and taught her to be a "tomboy ." In contrast,
many homosexuals do not behave like persons of the opposite sex, even though
they are drawn sexually and emotionally to persons of the same sex . Personal
statements of homosexual men and women do indicate, Hunt writes, that
"upbringing" probably did have some effect on the "effeminate" male and
"masculine" female, and the transvestite (a person who may be homosexual and
dresses, acts, and lives like a member of the opposite sex) .
Homosexuals have simply failed to attract the opposite sex ;
Less than 30 percent believed this brought about the
No investigator, Hunt reports, has found any evidence to support the belief
that homosexuals are unattractive to persons of the opposite sex . However,
there might be some truth to this idea, he states . Some homosexual men might
feel that they are not attractive to females because their appearance is not
"manly" enough . A few homosexual females might think they are not "feminine"
enough to attract males .
Many times, teenagers have feelings of
unattractiveness but tend to eventually outgrow them . Some do not, however,
because they have hidden tendencies toward homosexuality, and persons of the
opposite sex might translate this as a lack "sex appeal ." Hunt believes that
unattractiveness might, in some cases, be related to homosexuality, but as a
result of it, not a cause for it .
95Ibid., p .
Homosexuals are born that way . Forty percent believed that very few if
any homosexuals were "born that way ." Thirty percent,
however, did believe this theory.
This theory was previously discussed at length . Hunt surmises that
heredity does not specifically cause homosexuality, but may give some persons
the "tendency" to become a homosexual . With certain environmental influences,
such individuals might become homosexual .
The 1970 survey participants also were asked whether they felt
homosexuality could be "cured ." About 62 percent responded that they believed
it is a reversible "sickness" in about half of all people who practice this sexual
orientation . Forty percent thought that this was the case for all homosexuals,
but a "cure" was difficult . Fifty percent of respondents did not believe that very
many homosexuals could change their sexual orientation "by just wanting to",
while 29 percent doubted that any homosexual could do so . About 25 percent
of the participants felt that male homosexuals could become heterosexuals with
the help of "sexually skilled women," while about 33 percent felt that at least
half of all lesbians could become heterosexuals with the help of "sexually skilled
CONCLUSIONS AND POLICY CONCERNS
What is really known about the causes of homosexuality? An author who
has written on the subject in general concluded that a nature/nurture dichotomy
does not exist for the causes of homosexuality .
Both biological and
environmental factors, he believes, should be considered in developing a true
picture of homosexuality.96 There is considerable support for this view in the
research studies reviewed in this report . All the studies examined appeared
inconclusive in determining whether homosexuality is exclusively inborn or
environmental . It appears that no expert can definitively say what causes some
people to have this atypical sexual orientation . Many exceptions to what is
generally believed exist, whether concerning genetic determination or parental
influences . Research does seem to indicate, however, that there is not just one
absolute cause, but several factors that play a role in a homosexual orientation .
A key policy question remains--Is the homosexual orientation a "voluntary"
lifestyle choice? The research studies examined did not appear to provide
definitive answers to the question. If genetics and environmental influences
both play roles in the eventual life practice of homosexuality, as some of the
investigators seemed to believe, does an individual really consciously, and
"voluntarily" make the choice, or do inborn traits and the results of upbringing
contribute to an "irresistible" urge to maintain the homosexual orientation?
Ruse, Michael. Nature/Nurture : Reflections on Approaches to the Study of Homosexuality .
Journal of Homosexuality, v . 10, no . 3, Winter 1984. p . 141, 149 .
Abelin, Ernst L . The role of the father in core gender identity and in
psychosexual differentiation . In Selma Kramer, moderator, and Robert
C . Prall, reporter . The role of the father in the preoedipal years .
Journal of the American Psychoanalytic Association, v . 26, 1978 . p .
Adler, Tina . Study links genes to sexual orientation . APA monitor, v . 23, no .
2, Feb . 1992 . p . 12-13 .
Atkinson, Rita L ., Richard C . Atkinson, Edward E . Smith, and Ernest R .
Hilgard . Introduction to psychology, San Diego, Harcourt Brace
Jovanovich, publishers, 1987 . 744 p .
Bailey, J . Michael, and Richard C . Pillard . A Genetic study of male sexual
orientation . Archives of general psychiatry, v . 48, Dec . 1991 . p . 10891096 .
Bailey, J . Michael, Richard C . Pillard, Michael C . Neale, and Yvonne Agyei .
Heritable factors influence sexual orientation in women . Archives of
general psychiatry, v . 50, Mar . 1993 . p . 217-223 .
Barinaga, Marcia . Is homosexuality biological? Science, v . 253, Aug. 30, 1991 .
p . 956-960 .
the politics of
Bayer, Ronald . Homosexuality and American psychiatry :
diagnosis . Princeton, New Jersey, Princeton University Press, 1987 .
242 p .
Bell, Alan P ., and Martin S . Weinberg. Homosexualities : A study of diversity
among men and women . New York, Simon and Schuster, 1978 .
505 p .
Bermont, Gordon, and Julian M . Davidson . Biological bases of sexual behavioral
New York, Harper and Row, publishers, 1974 . 306 p .
Bullough, Vern L . Homosexuality : a history . New York, Garland STPM Press,
1979 . 196 p .
Burr, Chandler . Homosexuality and biology . The Atlantic monthly, Mar . 1993 .
p . 47-65 .
Campbell, Robert J .
Psychiatric dictionary, 6th ed ., New York, Oxford
University Press, 1989 . 811 p .
Eckert, Elke D ., Thomas J . Bouchard, Joseph Bohlen, and Leonard L . Heston .
Homosexuality in Monozygotic Twins Reared Apart . British Journal
of Psychiatry, v. 148, 1986 . p . 412-425 .
Facts that liberated the Gay community . Psychology today, Dec . 1975 . p . 52,
Fay, Robert E ., Charles F . Turner, Albert D . Klassen, and John H. Gagnon .
Prevalence and patterns of same-gender sexual contact among men .
Science, v . 243, Jan . 20, 1989 . p . 338-348 .
Garnets, Linda, and Douglas C . Kimmel . Lesbian and gay male dimensions in
the psychological study of human diversity . In Psychological perspectives
on human diversity in America . Jacqueline D . Goodchilds (ed.) Washington,
D .C ., American Psychological Association, 1991 . p . 137-192 .
Gebhard, Paul H . Incidence of overt homosexuality in the United States and
Western Europe . In Dept . of Health, Education, and Welfare . Alcohol,
Drug Abuse, and Mental Health Administration . National Institute of
Mental Health Task Force on Homosexuality :
final report and
background papers . John M . Livingood, ed . U .S . Govt . Print . Off.,
1976 . 79 p . DHEW publications no . (ADM) 76-357 .
Green, Richard . The "SISSY BOY SYNDROME" and the development of
homosexuality . New Haven, Connecticut, Yale University Press,
1987 . 416 p .
Greenson, Ralph R . Dis-identifying from mother : its special importance for the
boy. The International journal of psycho-analysis, v . 49, parts 2-3, 1968 .
p . 370-374 .
Henckne, Joel D . Conceptualizations of homosexual behavior, which preclude
homosexual self-labeling. Journal of homosexuality, v . 9, no . 4,
Summer 1984 . p . 53-63 .
Heston, L . L ., and James Shields . Homosexuality in twins : a family study and
a registry study. Archives of general psychiatry, v . 18, Feb . 1968 . p .
Hunt, Morton . Gay : what you should know about homosexuality . New York,
Farrar/Straus/Giroux, 1977 . 210 p .
Sexual behavior in the 1970s . Chicago, The Playboy Press Book, 1974 .
395 p .
Ibrahim, Azmy I . The home situation and the homosexual . The journal of sex
research, v . 12, no . 4, Nov. 1976 . p . 263-282 .
Isay, Richard A . Being homosexual : gay men and their development . New
York, Farrar/Straus/Giroux, 1989 . 159 p .
Kallmann, Franz J . Comparative twin study on the genetic aspects of male
homosexuality . The journal of nervous and mental disease, v . 115, no .
4, Apr . 1952 . p . 283-298 .
Kinsey, Alfred C ., Wardell B . Pomeroy, and Clyde E . Martin . Sexual behavior
in the human male . Philadelphia, W. B . Saunders Co ., 1948 . 804 p .
LeVay, Simon . A difference in hypothalamic structure between heterosexual and
homosexual men . Science, v . 253, Aug. 30, 1991 . p . 1034-1037 .
Muir, J . Gordon . Homosexuals and the 10% Fallacy . The wall street journal,
Mar . 31, 1993 . p . A14 .
Nicolosi, Joseph . Reparative therapy of male o osexuah
Jersey, Jason Aronson, Inc ., 1991 . 355 p .
Pillard, Richard C ., Jeanette Poumadere, and Ruth A . Carretta .
homosexuality familial? A review, some date, and a suggestion .
Archives of sexual behavior, v . 10, no . 5, 1981 . p . 465-475 .
Pillard, Richard C ., and James D . Weinrich . Evidence of familial nature of male
homosexuality . Archives of general psychiatry, v . 43, Aug. 1986 .
p . 808-812 .
Rogers, Susan M., and Charles F . Turner . Male-male sexual contact in the
U .S .A. : findings from five sample surveys, 1970-1990 . p . 491-519 .
Ruse, Michael . Nature/Nurture : Reflections on approaches to the study of
homosexuality. Journal of homosexuality, v . 10, no . 3, Winter 1984 .
p . 141-149 .
Saghir, Marcel T ., and Eli Robins .
Male and female homosexuality:
comprehensive investigation . Baltimore, Williams & Wilkins Co ., 1973 .
341 p .
Sanders, Stephanie A., June Machover Reinisch, and David P . McWhirter .
Homosexuality/heterosexuality : an overview. In McWhirter, David P .,
Homosexuality/heterosexuality: concepts of sexual orientation . New York,
Oxford University Press, 1990 . Kinsey Institute Series, v . 2 . p . xix-xxvii .
Smith, Tom W . Adult sexual behavior in 1989 : number of partners, frequency
of intercourse and risk of AIDS . Family p anning perspectives, v . 23,
no . 3, May/June 1991 . p . 102-107 .
Voeller, Bruce . Some uses and abuses of the Mosey Scale . In McWhirter, David
Sanders, and June Machover Reinisch,
Homosexuality/heterosexuality : concepts of sexual orientation . New
York, Oxford University Press, 1990 . p . 32-38 .
Wiedeman, George H . Homosexuality, a survey . Journal of the American
Psychoanalytic Association, v . 22, no. 3, 1974. p. 651-696 .
Zuger, Bernard . Monozygotic twins discordant for homosexuality : report of a
pair and significance of the phenomenon . Comprehensive psychiatry,
v. 17, no. 5, Sept ./Oct . 1976. p. 661-669 .
APPENDIX A. Types of Homosexual Behavior of Some
Men and Women
The following categorizations are types of behavior many homosexual men
and women exhibit that are extracted from samples researchers Alan Bell and
Martin Weinberg presented in their book, Homosexualities . 97 The descriptions
are summaries of how these analysts described each homosexual behavior type .
As with any categorization, they should be used with caution .
Partners in this type of relationship were closely bound
together, and depended upon each other for sexual and
interpersonal satisfactions rather than upon outsiders . They
had a special relationship and did not seek other partners .
They had the smallest number of sexual problems, and were
unlikely to regret their homosexuality . They seldom went to
pick-up establishments such as bars or baths, but tended to
spend more evenings at home together and less leisure time
in individual pursuits . They reported high levels of sexual
activity and their sex lives were gratifying to them . They
appeared well-adjusted and had rarely experienced difficulty
related to their sexual orientation, such as being arrested,
trouble at work, or assault and robbery . Most men and
women homosexuals of this type were more self-accepting,
less depressed and lonely, and the happiest of all the types
Individuals in these type of relationships were not as
fully committed to one partner as Close-Coupleds . They
lived together, but were not happy with their circumstances
and relied more on a large circle of homosexual friends to
seek satisfactions . They placed less importance on their
relationship with their partner and did more "cruising ."
They were less happy because they worried about their
cruising and the possibility of their actions being publicly
exposed . They reported more sexual activity than the typical
homosexual respondents . Psychologically, however, they
were about as content, vivacious, depressed, tense, paranoid,
or worried as the average homosexual respondent .
Be11 and Weinberg, Homosexualities, p . 219-228 .
The Close- and Open-Coupled groups were similar to
married heterosexuals. Functionals, however, were more
closely compared with "swinging singles ." Their lives seemed
to be organized around their sexual experiences . They had
more sexual activities with a larger number of partners than
any of the other groups defined . They were the least likely
to regret being homosexual . They cruised frequently and
generally displayed a great deal of involvement in the gay
world . They were not interested in finding a partner to
settle down with . They engaged in a variety of sexual
activities, considered themselves to have high sex appeal, and
had few, if any, sexual problems . Of all the groups, they
were the most interested in sex, vivacious, and the most
involved with a number of friends . They were the most
likely to have been arrested, booked, or convicted for a
"homosexual" offense . This might have been the case because
of their greater openness, high attendance at gay bars, and
perhaps their relative lack of concern or suspicion of others,
in addition to a certain degree of recklessness .
The dysfunctional groups' lives appeared to offer them
little gratification, and they seemed to have great difficulty
in managing their existence . This group displayed the
poorest adjustments sexually, socially, and psychologically
than the other homosexual respondents . They were the most
regretful about their homosexuality . They had more sexual
problems than the other groups, and were particularly prone
to worry about sexual adequacy . They cruised frequently,
had relatively large numbers of partners, and complained
about not having sex often enough . Also, they had problems
finding a suitable partner, and tended to think that they
were sexually unappealing . There were more reports of
robbery, assault, or job difficulties in the men among this
group . Furthermore, they were more likely to have been
arrested, booked, and convicted regardless of the reason . The
females within this group were less vivacious, and more
likely to have undergone long-term professional help for
emotional problems . The men were more lonely, depressed,
worrisome, tense, and unhappy than any of the other men
The most prominent characteristic of this group is their
lack of involvement with others . They had the lowest level
of sexual activity of all the groups, had fewer partners, felt
they had low sex appeal, and tended to have a number of
sexual problems . Also, they were less interested in sex than
the other men . The Asexuals were the least likely group to
consider themselves as exclusively homosexual . They were
less overt about their homosexuality, and had fewer
homosexual friends . Most of the men and women in this
group spent their leisure time alone, and had less frequent
contact with their friends. They described themselves as
lonely, and the men felt unhappy . The women in the group
were most likely to have sought professional help concerning
their sexual orientation, but to have quickly given up
counseling. They tended to have the highest incidence of
suicidal thoughts, (not necessarily related to their