Consider the implications of the
following excerpts, they have been chosen to make one consider the relationship
between the physical brain, gender identity, gender behavior and hormones.
Some discuss DES directly others do not. Some also indicate the importance
of androgens (testosterone is an androgen) in masculinizing the brain. Keep
in mind that DES was used to treat prostate cancer precisely because it was
very effective at lowering testosterone levels.
These three papers draw a
great deal of attention, both pro and con. Some believe that the
small sample of brains studied makes the findings suspect. One thing
which most people don't consider is the reason these researchers
went looking at the BST in the first place and that is because of
the large amount of research on other mammals which shows the BST is
different between males and females and that it is affected during
pre and neonatal development by hormone levels.
From - A Sex Difference in the Human Brain and its Relation
to Transsexuality. J-N Zhou, M.A. Hofman, L.J. Gooren, D.F. Swaab. 2)
“Transsexuals have the strong feeling,
often from childhood onwards, of having been born the wrong sex. The possible
psychogenic or biological etiology of transsexuality has been the subject
of debate for many years [1,2]. Here we show that the volume of the central
subdivision of the bed nucleus of the stria terminalis (BSTc), a brain area
that is essential for sexual behaviour [3,4], is larger in men than in women.
A female-sized BSTc was found in male-to-female transsexuals. The size of
the BSTc was not influenced by sex hormones in adulthood and was independent
of sexual orientation. Our study is the first to show a female brain structure
in genetically male transsexuals and supports the hypothesis that gender
identity develops as a result of an interaction between the developing brain
and sex hormones [5,6]. ”
A second report on the BST indicates 3) "the present study of SOM
neurons in the human BSTc provides unequivocal new data supporting the view
that transsexualism may reflect a form of brain hermaphroditism.”
Which was followed by a third report 61) "The human BST-dspm seems
to become sexually dimorphic at approximately puberty."
Note: the
BST is a very small part of the brain and in research animals, it
has more to do with sexual behavior as opposed to gender behavior.
On the research page, papers which deal with another part of the
brain called the LC (locus coeruleus)
are discussed in relation to gender behavior in research animals.
Animal research seems to be pointing to a variety of ways in which
different parts of the brain are masculinized. For instance some
parts (mouse brain) such as the BST seem to require the conversion
of testosterone into estrogen and it is the estrogen acting through
estrogen receptors which masculinizes this part of the brain. On the
other hand other parts of the brain such as the LC seem to depend
solely on androgen acting via androgen receptors to become
masculinized.
From - Simon Baron-Cohen's book "The Essential
Difference, The Truth about the Male and Female Brain." Quotes from pages
99 and 98 respectively, Copyright 2003. Published by Basic Books (Amazon.com
listing) 198).
"There was a time when women were prescribed
a synthetic female hormone (diesthylstilbestrol) in an attempt to prevent
repeated spontaneous miscarriages. Boys born to such women are likely
to show more female typical behaviors enacting social themes in their
play as toddlers, for example, or caring for dolls. This is a further
indication that hormone levels can affect the ability to empathize."
"Most people who want to determine
whether a person is male or female stop at this first level. But even
if you are genetically female, and even if you are genitally female,
you could be more male gonadally, and have a male brain and male sex-typical
behavior. Conversely, even if you are genetically and genitally male,
you could be more female gonadally, or you could have a female brain and
female sex-typical behavior. And prenatal testosterone, an androgen,
oozing from your testes if you are genetically and gonadally male, or
dripping out of your adrenal glands if you are genetically and gonadally
female, appears to be one important variable in determining your brain
type or your sex-typical behavior.
There appear to be three points in development when testosterone
secretion really surges. The first is the prenatal period, between
eight and twenty four weeks into the pregnancy. The next one is around
five months after birth. A final peak is at puberty. These periods are
referred to as the "activational" periods, because it is at these times
that the brain is thought to be most sensitive to such hormonal changes.
The sex hormones are said to have a prenatal activating effect on the
brain."
Dr. Baron-Cohen is a professor of psychology and psychiatry
at Cambridge University.
This is the closest I have come to a drug company
admitting an association between prenatal hormone exposure and gender
identity.
"Although biologic factors,
such as gender complement and the prenatal hormonal milieu, largely
determine gender identity, the formation of a secure, unconflicted gender
identity and gender role is influenced by social factors, such as the
character of the parents' emotional bond and the relationship that each
of them has with the child."
From - About Merck
"Merck & Co., Inc. is a leading research-driven
pharmaceutical products and services company. Merck discovers, develops,
manufactures and markets a broad range of innovative products to improve
human and animal health, directly and through its joint ventures."
This excerpt is from a report which I mentioned
on the discussion page and is from a symposium held by the
"4. Sexual differentiation
of the mammalian brain starts during fetal development and continues
after birth (Kawata, 1995; Swaab et al., 2001). It is hypothesised that
in humans, in common with all other mammals studied, hormones significantly
influence this dimorphic development although, at present, the exact
mechanism is incompletely understood. It is also postulated that these
hormonal effects occur at several critical periods of development of
the sexual differentiation of the brain during which gender identity
is established, initially during the fetal period, then around the time
of birth; and also post-natally. Factors which may contribute to an altered
hormone environment in the brain at the critical moments in its early
development might include genetic influences (Landen, 1999; Coolidge
et al, 2002) and/or medication, environmental influences (Diamond et
al., 1996; Whitten et al., 2002), stress or trauma to the mother during
pregnancy (Ward et al., 2002; Swaab et al., 2002)."
Please note the word "medication" in the above
excerpt.
Note: this is a living document and is subject
to change. The fact that it has been signed by many doctors, professors and
professional people makes it very important. It is a short document and only
takes a minute to read. If you haven't yet read it then please do so.
Notes on Gender Identity Disorder by Anne Vitale, Ph.D. Gender Identity
Disorder: A Brief Description of the Problem June 10, 1996 -Revised
April 2, 1997 201):
"Nature takes male differentiation further
by having the newly formed male testes flood the brain with male hormones
at around the third month of pregnancy. This sudden surge of brain masculinizing
hormones -- the creation of the male gendermap -- occurs again in males
somewhere between the second and twelfth week after birth. Importantly,
there is no corresponding feminizing hormonal surge sequence observed
in females."
"This leads one to consider the possibility
that male hormonal surges must occur not only in sufficient amounts,
but also during a short window of time to cause masculinization of the
gendermap. If there is insufficient androgen (male hormone), or the surge
comes too early or too late, the gendermap may be only partially imprinted
as male. These disruptions of hormonal surges may come from a variety
of sources. A partial list would include a disorder in the mother's endocrine
system such as a hormone secreting tumor, common maternal stress, maternal
medications or some other toxic substances yet to be identified."
This report was also mentioned on the discussion
page (1)(2).
It is about a group of boys who were born with a rare medical condition
called cloacal exstrophy 24W). The point is you can't just make
a boy with a normal prenatal hormonal environment into a girl by doing a
bit of surgery and then raising him as a girl.
"Two Johns Hopkins Children's Center studies
confirm that prenatal exposure to normal male hormones alone dictates
male gender identity in normal XY male babies, even if they are born
without a penis. The results seriously question the current practice
of sex-reassigning some of these infants as females, performing castrations
or other surgery to align them cosmetically and hormonally with a female
role."
"Hopkins researchers followed the development
of 27 genetically male children -- with normal XY male chromosomes.
All were born with cloacal exstrophy, a rare, major defect characterized
by lack of a penis, but presence of normal testicles, indicating exposure
to normal male hormone patterns before birth. Twenty-five of the children
were reassigned by physicians at birth, castrated and raised as females.
Presenting the findings at the Lawson Wilkins Pediatric Endocrine Society
Meeting in Boston today, William G. Reiner, M.D., a child and adolescent
psychiatrist and urologist at the Hopkins Children's Center, reported
that the majority of these children, between the ages of 5 and 16, have
subsequently "reassigned" themselves back to males. All 27 showed strong
male behaviors, activities and attitudes."
You can't teach an old dog new tricks, or can you?
From - Transsexualism :
The Current
Medical Viewpoint Second Edition, 18th January
1996. Produced for the Parliamentary Forum on Transsexualism
Chair : Lynne Jones, MP by
Dr. R Reid, Hillingdon Hospital (Medical Sub-Group Convenor)
Dr. Domenico di Ceglie, Tavistock Clinic
Mr. James Dalrymple, London Bridge Hospital
Professor Louis Gooren, University of Amsterdam
Professor Richard Green, Charing Cross Hospital Professor John Money, Johns Hopkins Hospital,
USA
This is an older document from 1996, please note Dr. "Psychosexually neutral" Money on the list of names.
Remember him from the discussion page and the
John/Joan
story? Also note his name on the Complete Androgen Insensitivity study
discussed earlier on this page as well as studies 158 and 159 listed
above.
"6.4 It is a viewpoint of this kind
that Money suggests in an authoritative paper <<The Concept of
Gender Identity Disorder in Childhood and Adolescence after 37 years>>
where he states 'causality with respect to gender identity disorder is
subdivisible into genetic, prenatal hormonal, postnatal social, and postpubertal
hormonal determinants' and suggests "there is no one cause of a gender
role.....Nature alone is not responsible, nor is nurture, alone. They
work together, hand in glove.(15)"
"6.6 Most recently, a study has
been carried out of a region in the hypothalamus of the brain which
is smaller in women than in men. Strikingly, the region was of female
size or smaller in six male-to-female transsexuals, regardless of hormone
treatment. This result supports the hypothesis that gender identity stems
from an interaction between the developing brain and sex hormones (17)."
Woof!!
From - Gender Benders & Endocrine Disruptors
around You, By Elizabeth Lee Vliet, MD Excerpted and
condensed from It’s My Ovaries, Stupid, pgs. 83 – 107
Scribner, 2003
279)
"Some Health Consequences of DES
DES Daughters
Deformed uteruses, fallopian
tubes, and ovaries
Lowered egg production
Higher rates of infertility,
ectopic pregnancies, miscarriages, and premature
babies
Higher rates of endometriosis,
uterine tumors, breast tumors, and pituitary tumors
Increased frequency of ovarian
cysts and abnormal follicles Immune system
problems
Abnormal glucose tolerance and
glucose utilization
Abnormal development of
gender-specific sexual behavior in DES offspring
(feminized males and masculinized females),
suggesting that DES caused abnormal sex
differentiation during fetal development
DES Sons
Increased genital defects,
undescended testicles, and stunted testicles and
penises
Low sperm counts, abnormal
sperm, and reduced fertility
Higher rates of testicular
cancer at earlier ages
Immune system problems
Abnormal glucose tolerance
and glucose utilization
Abnormal development of
male sexual behavior "
These researchers (two of which have been
or presently are associated with the Kinsey Institute) compiled
data from nineteen different studies and made the following observations.
"Nineteen studies on the behavioral effects
of prenatal exposure to hormones administered for the treatment of at-risk
human pregnancy are reviewed. Because the role of prenatal exposure to
hormones in the development of human behavioral sex differences is potentially
confounded by society's differential treatment of the sexes, comparisons
between exposed and unexposed subjects were evaluated and summarized separately
for male and female subjects. Therefore, this review focuses on data for
individuals whose prenatal hormone environments were atypical relative to
what is normal for their own sex. Overall, it appears that prenatal exposure
to androgen-based synthetic progestin exerted a masculinizing and/or defeminizing
influence on human behavioral development, whereas prenatal exposure to
natural progesterone and progesterone-based synthetic progestin had a feminizing
and/or demasculinizing influence, particularly among female subjects. The
data on prenatal exposure to synthetic estrogen derive primarily from subjects
exposed to diethylstibestrol (DES). DES-exposed male subjects appeared
to be feminized and/or demasculinized, and there is some evidence that
exposed female subjects were masculinized. These findings are discussed
in the context of prenatal hormonal contributions to sexually dimorphic
behavioral development both within and between the sexes. Recommendations
for the conduct of future research in developmental behavioral endocrinology
are presented"
"Ten males exposed to diethylstilbestrol
(DES), a nonsteroidal synthetic estrogen, during gestation were compared
to their matched, unexposed brothers on measures of brain hemispheric
specialization for processing nonlinguistic spatial information and cognitive
abilities. DES exposure was associated with reduced hemispheric laterality
and lowered spatial ability. These data provide direct evidence of a relationship
between brain laterality, spatial cognitive ability, and prenatal exposure
to hormones in human males. Further, the implications of these findings
for understanding sexual differentiation of the human brain are discussed."
An excerpt from a report published in 1981 Check out the marital status comparing exposed to unexposed males.
From - Randomised trial of
high doses of stilboestrol and ethisterone
therapy in pregnancy: long-term follow-up of the children. V Beral
and L Colwell.
"The earlier in pregnancy the therapy
began, the higher the prevalence rate of abnormalities (X2 for trend,
p less than 0.02). No malignant tumours were reported. For males, the
proportion reported to be married or living as married was lower in the
exposed than in the unexposed group (32% and 62% respectively). The proportion
was lower the earlier in pregnancy hormonal exposure occurred and the
higher the total hormone dose to which they were exposed (X2 for trend,
p less than 0.02). These findings suggest that some interference with
sexual function may not be uncommon in males exposed to high doses of
stilboestrol and ethisterone while in utero."
Stilboestrol is one of the many brand
names DES was sold under. Ethisterone (ethis·ter·one)
([schwa]-this¢t[schwa]r-[omacr]n) a semisynthetic progestin,
which may be considered a derivative of both progesterone and of testosterone.
Called also anhydrohydroxyprogesterone, pregneninolone, and ethinyl
testosterone.
From - Does prenatal exposure
to diethylstilbestrol (DES) have psychiatric consequences? by Verdoux
H., published in the French journal Annales Medico-Psychologiques, Vol
158(2) (pp 105-117), 2000 (no link available)
Abstract “Diethylstilbestrol (DES) had been
widely used around the word in pregnancy care until the discovery in
the early 1970s of the teratogenic and carcinogenic effects of this drug.
The genital and obstetrical iatrogenic effects of the intrauterine exposure
to DES are now well established. However, the potential impact of the DES
and related xenoestrogen on the foetal neurodevelopment are poorly known.
It has been suggested that prenatal DES exposure may modify the cerebral
lateralisation. A more speculative issue with regard to the possible neurodevelopmental
consequences of DES exposure is the possible impact on gender-identity
and gender-related behavior. Prenatal DES exposure may be also a risk factor
for psychiatric disorder in adulthood. This increased liability cannot
be totally explained by the genital and reproductive consequences of DES
exposure, since it can also be found before the appearance of such complications
and/or in subjects unaware of their exposure to DES and also exists in
DES-exposed sons who do not present with somatic complications. Most previous
studies have assessed the links between perinatal DES exposure and increased
risk of depression. A few reports also suggest that subjects exposed to
DES may be at greater risk of eating or psychotic disorders. Further research
on the neurodevelopmental consequences of xenoestrogen exposure is required
from an aetiological perspective, but also from a preventive point of view."
At least these people are willing to openly speculate on the
possibility.
From - A psycho-endocrinological overview of transsexualism.
A Michel, C Mormont and J J Legros 237)
"Gender identity disorders in subjects presenting
perinatal hormonal abnormalities Gender identity disorders may be the
consequence of an atypical hormonal environment such as congenital adrenal
hyperplasia, resistance to androgens or even exogenous hormonal impregnation
(the absorption of diethylstilboestrol treatment during pregnancy). In
the majority of cases, these subjects do not develop towards transsexualism
(33±43). Some researchers have documented changes in behaviour (e.g.
behaving as a tomboy) and sexual orientation (44±48) in these subjects,
although others have not done so (40, 49)."
From - Cognitive ability and cerebral lateralisation
in transsexuals. PT Cohen-Kettenis, SH van Goozen, CD Doorn, and LJ Gooren
238)
"It is still unclear to what extent cross-gender
identity is due to pre- and perinatal organising effects of sex hormones
on the brain. Empirical evidence for a relationship between prenatal hormonal
influences and certain aspects of gender typical (cognitive) functioning
comes from pre- and postpubertal clinical samples, such as women suffering
from congenital adrenal hyperplasia and studies in normal children. In
order to further investigate the hypothesis that cross-gender identity
is influenced by prenatal exposure to (atypical) sex steroid levels we
conducted a study with early onset, adult male-to-female and female-to-male
transsexuals, who were not yet hormonally treated, and nontranssexual adult
female and male controls. The aim of the study was to find out whether early
onset transsexuals performed in congruence with their biological sex or their
gender identity. The results on different tests show that gender differences
were pronounced, and that the two transsexual groups occupied a position
in between these two groups, thus showing a pattern of performance away
from their biological sex. The findings provide evidence that organisational
hormonal influences may have an effect on the development of cross-gender
identity."
"Animal studies have shown that prenatal
exposure to the anticonvulsant drugs phenobarbital and phenytoin alters
steroid hormone levels which consequently leads to disturbed sexual differentiation.
In this study, possible sequelae of prenatal exposure to these anticonvulsants
on gender development in humans were investigated."
"Out of 243 exposed and 222 control subjects
who were asked to volunteer, 147 exposed subjects (72 male, 75 female)
and equal numbers of their matched control subjects participated in
the follow-up study."
" Three prenatally anticonvulsant-exposed
subjects were transsexuals and had undergone sex reassignment surgery,
a remarkably high rate given the rarity of transsexualism."
"Functional sex differences in reproduction,
gender and sexual orientation and in the incidence of neurological
and psychiatric diseases are presumed to be based on structural and
functional differences in the hypothalamus and other limbic structures.
Factors influencing gender, i.e., the feeling to be male or female,
are prenatal hormones and compounds that change the levels of these hormones,
such as anticonvulsants, while the influence of postnatal social factors
is controversial. Genetic factors and prenatal hormone levels are factors
in the determination of sexual orientation, i.e. heterosexuality, bisexuality
or homosexuality."
From -Perinatal factors in the development of gender-related
play behavior: sex hormones versus pregnancy complications. HF Meyer-Bahlburg,
JF Feldman, P Cohen, and AA Ehrhardt.
"The results of paired t-tests showed a
number of hypomasculinization effects for the hormone-exposed groups.
Controlling for the effects of pregnancy complications and age at study
by exploratory hierarchical multiple regression analysis indicated that
these variables did not account for the hormone-exposure effects. Our
results provide further evidence that prenatal hormones influence the
sex-dimorphic play behavior of human children in the same direction as
that of other mammals."
Two excerpts from a report authored by Dr. Diamond, predating Dr.
Reiner's work with cloacal exstrophy.
"I'm aware of at least five other cases
where a sex reassignment of a normal male that has lost his penis and
then raised as a girl has reverted to living as a male. Now, after some
30-plus years of these surgeries, there is still not a single report of
a non-intersexed male having been successfully raised as a contented androphilic
woman."
"FIRST RECOMMENDATION: That there be a
general moratorium on sex assignment cosmetic surgery when it is done
without the consent of the patient."
Emedicine : Sexuality: Gender Identity. Author:
Shuvo Ghosh, MD, Fellow, Developmental/Behavioural Pediatrics, Department
of Pediatrics, McGill University Health Centre/Montreal Children's Hospital
Coauthor(s): Leslie Walker, MD, Head, Section of Adolescent Medicine,
Assistant Professor, Department of Pediatrics, Georgetown University
Medical Center
202).
"This rudimentary gender identity, although
incomplete, is an important determinant in gender development. The dimorphism
of the brain itself suggests this. Nevertheless, variations may occur
when endogenous or exogenous factors create a fetal environment where hormone
levels do not follow the genetically determined pattern. The gender bias
of these infants may be tilted away from one that correlates with the genotype.
Such variations are discussed below."
"Conditions resulting from genetic or hormonal
influences to the usual process of fetal development cause a number
of differences in the resulting fetus. When levels of prenatal hormones
are altered, phenotypic progression is altered as well. The inherent
brain bias towards one sex may be discordant with the genetic makeup of
a fetus, or even with its external anatomic presentation. Other variations
lead to psychologic stressors in later development but have their origin
in the prenatal stage. A number of such conditions exist that may ultimately
affect a child’s gender identity."
"Experimental studies revealed that transient
action of sex steroids during perinatal period is crucial for the development
of male sexual behavior and sexually dimorphic brain anatomy. Meanwhile,
the lack of gonadal steroids in female foetus and estrogen effects at puberty
determine female behavior together with female type of anatomical brain
structures and of endocrine functions. In men psychic sex consists of gender
identity (self-estimation), gender role (objective estimation of sex behavior).
In addition, a sexual psycho-orientation (hetero-, bi- or homosexual) has
been distinguished. Although it is believed that gender depends on the
socio-environmental influences such as rearing, learning and individual
choice, the biological factors are considered to be most important. This
concept arises from recent study on patients with gender dysphoria syndrome
(transsexualism). In intersexualism, in genetic men with disturbances
of sexual differentiation of external genitalia because of the lack of
testoterone production or action in peripheral tissues (male pseudohermaphroditism)
or in genetic women with ambiguous genitalia because of the presence and
action of androgens (female pseudohermaphroditism), a discordance between
the formal sex (assigned after the birth) and the psychic gender may appear.
In these individuals the legal sex established according to somatic and/or
genetic sex at birth may be incompatible with their actual gender identity
and role. The knowledge about gender identity is necessary at the decision
of eventual (!) surgical correction of sex organs in patients with ambiguous
genitalia. This decision should depend not on the expected, but on the actual
gender identity of the individual patient. Meantime, early bilateral gonadectomy
in patients with gonadal dysgenesis and male pseudohermaphroditism is an
indication for life because of the highest risk of germ cell carcinoma.
"
From - Androgens, brain, and behavior, DR Rubinow and PJ Schmidt,
National Institute of Mental Health, Bethesda, MD 20892-1276, USA.
"OBJECTIVES: This article defines androgens (and
anabolic steroids), describes their mechanisms of action, and summarizes
their behavioral effects and relevance in animals and humans. METHOD:
A MEDLINE-derived review of the literature on androgens and behavior was
performed; pivotal earlier publications were also obtained and included
in the review. RESULTS: In animals, the effects of androgens on brain structure
and function are well-established and profound, with behavioral implications
extending far beyond reproduction. Androgens play a prominent role in the
organization or programming of brain circuits, which are subsequently
activated by gonadal steroids. In humans, roles for androgens have been
described, albeit inconsistently, in the regulation of sexuality, aggression,
cognition, emotion, and personality. The relevance of androgens for psychiatry
is further suggested by gender-related differences in pharmacokinetics/pharmacodynamics
and in the prevalence, course, and treatment response characteristics of
several psychiatric disorders. Direct psychoactive effects of exogenously
administered androgens have been described for many years, most recently
in reports of the psychotoxic effects of anabolic steroids. CONCLUSIONS:
Data from both animals and humans suggest that the biological and behavioral
responses to androgens are context-dependent. "
"First, it was expected that DES-daughters
would be more masculinized in their self-concepts than non-exposed
control subjects. Our second hypothesis was that DES-daughters would
be lower in body-acceptance and sexual satisfaction, and would have
stronger wishes and more emotionality concerning reproduction. Contrary
to expectations, DES-daughters were not more masculinized than controls.
Instead, they tended to have higher scores on femininity. Furthermore,
no differences between DES-daughters and controls appeared in body-acceptance
and sexual satisfaction. However, the DES-daughters reported a stronger
wish for having children and expressed more emotionality concerning the
subject."
The link between prenatal hormone exposure and behavior in primates
was made almost 40 years ago by altering the prenatal hormonal environment
of female rhesus monkeys.
"In 1964, Goy, Young and Phoenix began
investigating the effects of prenatal hormone alterations in rhesus
monkeys. They produced the first masculinized genetic female rhesus
monkey and demonstrated that the principles developed in guinea pigs
applied to nonhuman primates and, by extension, to humans. These
landmark studies also showed that differences in male and female juvenile
rhesus monkeys' social behavior, which occur when the young monkeys are
not secreting gonadal hormones, were organized by the prenatal hormone
environment. This was the first clear evidence that prenatal hormones actually
altered the structure of the nervous system, instead of changing its sensitivity
to the activating effects of gonadal hormones. Subsequent work in other
laboratories throughout the world has unequivocally provided evidence of
specific structural changes within the developing nervous system-changes
organized by hormones during the period of sexual differentiation."
Note: Although the CDC has his initials wrong they list a book in
their DES bibliography which he co-authored with Bruce McEwen. Goy
RB, McEwen BS, “Sexual differentiation of the brain,” Cambridge (MA):
The MIT Press; 1980. Amazon.com has his initials listed correctly.
Of interest is another research paper in which Dr. Goy was involved
indicates that DES exposure caused a slight masculinization of female
rhesus monkeys but had no effect on male monkeys. Is this due to the non-monotonic
nature of DES? i.e.,47) which shows AR binding levels in the BSTc restored
almost to normal on gonadectomized male rats, See Figures 1and 2.
185). "However, it is recognized
in endocrinology that low concentrations of a hormone can stimulate
a tissue, while high concentrations can have the opposite effect."
"Thus, DESDP-treated females displayed
a limited behavioral masculinization. Whether this limitation was due
to dosage and/or timing or to a selective action of DESDP was not determined.
DESDP-treated males were not altered in any measurable way compared
to untreated males."
"Effects of prenatal exposure to PCBs,
measured in maternal and cord plasma, on the masculine and composite
scales were different for boys and girls (p <.05). In boys, higher
prenatal PCB levels were related with less masculinized play, assessed
by the masculine scale (p(maternal) =.042; p(cord) =.001) and composite
scale (p(cord) =.011), whereas in girls higher PCB levels were associated
with more masculinized play, assessed by the composite scale (p(PCBmilk)
=.028). Higher prenatal dioxin levels were associated with more feminized
play in boys as well as girls, assessed by the feminine scale (p =.048).
These effects suggest prenatal steroid hormone imbalances caused by prenatal
exposure to environmental levels of PCBs, dioxins, and other related organochlorine
compounds."
I've included this article to show that even some courts are considering
the possibility that gender identity is developed in part before birth.
"18. His Honour pointed to
the problem arising from the fact that the word ‘transsexual’ suggested
a sexual transition, passing from one sex to the other, but he said
that this did not convey the fact that transsexual people normally experience
themselves as belonging to the other sex from birth and therefore before,
as well as after, the hormonal or surgical procedures."
"22. In coming to his conclusions,
his Honour relied upon the evidence of specialist witnesses, including
Professor Gooren, Professor McConoghy, Professor Diamond and Dr Cornelis
Greenway. He recorded the observation of Professor McConoghy that Kevin
presented as an intelligent, emotionally warm man, who would be accepted
socially as completely masculine. Professor McConoghy also expressed
the view that Kevin’s “brain sex or mental sex is male.” His Honour noted
that Professor McConoghy, in referring to the evidence of Professor Diamond,
deposed that he agreed with Professor Diamond’s opinion “that further research
will confirm the present evidence that brain sex or mental sex is a reality
which would explain the persistence of a gender identity in the face of
or contrary to external influences."
"29. His Honour identified the following
as a key passage in the reasons of Ormrod J:
“It is common ground between all
the medical witnesses that the biological sexual constitution of an individual
is fixed at birth (at the latest), and cannot be changed, either by
the natural development of organs of the opposite sex, or by medical
or surgical means. The respondent’s operation, therefore, cannot affect
her true sex."
