The Biological Basis of Transgender Identity - The Scientific Evidence

Summary

Dr. Jamie discusses the biological basis of gender, debunking the myth that gender identity is influenced by environment or upbringing. They explain that gender is innate, supported by studies on gender manipulation, twin studies, androgen exposure in utero, and brain anatomy. The video emphasizes that gender identity is a natural part of biological diversity, not a socio-cultural construct or a passive response to anatomy.

Takeaways

• 🧠 Gender identity has a strong biological basis, with evidence refuting the idea that it is determined by environmental factors such as parental or peer influence.
• 🔍 The term 'sex' refers to what is assigned at birth (male, female, intersex), while 'gender' or 'gender identity' describes one's internal perception as a man, woman, something in between, or neither.
• 📚 The concept that gender is a socio-cultural construct is largely unsupported by evidence, though gender roles may be influenced by socio-cultural factors.
• 🧬 Gender is not a passive response to anatomy or sex assigned at birth; it is instead a spectrum influenced by neurophysiological and neuroanatomical development.
• 👶 Studies on gender manipulation, such as the Rainer and Dearheart study on genetic males with cloacal exstrophy, demonstrate that even with significant anatomical and environmental influence, gender identity is biologically rooted and established in utero.
• 👯 Twin studies show high genetic concordance for transgender identity among identical twins (40%), indicating a strong genetic component.
• 💉 Androgen exposure in utero significantly influences gender identity, as seen in cases of congenital adrenal hyperplasia and androgen insensitivity syndrome, where hormonal factors play a critical role in gender identity development.
• 🧠 Brain anatomy studies show that trans women have brain structures similar to cis women, suggesting that gender identity is reflected in brain anatomy.
• 📊 The preponderance of scientific evidence supports the conclusion that gender identity is a biological phenomenon rather than a result of environmental or socio-cultural influences.
• 🏫 Teaching children about gender differences is unlikely to influence their gender identity but can reduce stigma, fear, and bullying towards transgender individuals.

Q & A

What is the main topic discussed by Dr. Jamie in the video?

The main topic discussed by Dr. Jamie is the biological basis of gender and the evidence supporting the idea that gender identity is determined by biological factors rather than environmental or socio-cultural influences.

What are the terms 'sex' and 'gender identity' as defined by Dr. Jamie?

According to Dr. Jamie, 'sex' or 'natal sex' is assigned at birth and includes terms like male, female, and intersex. 'Gender identity' describes a person's innermost perception of being a man, woman, something in between, or neither, and is not always visible to others but is enduring.

What does Dr. Jamie refute regarding the influence of environment on gender identity?

Dr. Jamie refutes the idea that gender identity is determined by the environment, such as parental influence or peer influence, stating that the actual evidence shows this belief to be misguided.

What are the four groups of studies that support the biological basis of gender according to Dr. Jamie?

The four groups of studies supporting the biological basis of gender are gender manipulation studies, twin studies, studies of Androgen exposure in utero, and brain anatomy studies.

Can you summarize the findings of the gender manipulation study by Rainer and Gearhart in 2004?

The study by Rainer and Gearhart involved 16 genetic male infants with cloacal exstrophy who were surgically modified to have female genitalia and raised as females. The study found that all of them, when they grew older and knew their medical history, identified as male, suggesting that gender identity is not a passive response to sex assigned at birth or genitalia.

What does the term 'concordance' refer to in the context of twin studies?

In the context of twin studies, 'concordance' refers to the degree to which both twins in a pair share the same trait or condition, such as gender identity. High concordance in identical twins indicates a strong genetic component.

How does Androgen exposure in utero influence gender identity according to the studies mentioned by Dr. Jamie?

According to the studies, Androgen exposure in utero can have a strong influence on gender identity later in life. For example, genetic females exposed to high levels of Androgens were more likely to identify as male, while genetic males with Androgen insensitivity syndrome, despite having male chromosomes, identify as female.

What did the brain anatomy study by Zhou et al. in 1995 reveal about the brains of trans women?

The brain anatomy study revealed that the brains of trans women are anatomically similar to those of cisgender women, suggesting a biological basis for gender identity that aligns with their experienced gender rather than their assigned sex at birth.

What is the conclusion Dr. Jamie draws from the scientific evidence presented?

Dr. Jamie concludes that there is a significant amount of scientific evidence supporting the idea that gender identity is a product of biological factors and not influenced by environmental or socio-cultural factors or a passive response to sex assigned at birth.

What does Dr. Jamie suggest about the impact of teaching children about gender differences on their gender identity?

Dr. Jamie suggests that teaching children about gender differences would have no influence on their gender identity, and instead, educating children about gender may lead to less stigma, fear, bullying, hate, and bigotry towards transgender individuals.

What is the stance of Dr. Jamie on the concept of 'rapid onset gender dysphoria'?

Dr. Jamie dismisses the concept of 'rapid onset gender dysphoria' as 'Malarkey,' implying that the idea that children can be influenced by their peers to become transgender is unfounded and not supported by scientific evidence.

Outlines

00:00

🧬 Biological Basis of Gender Identity

Dr. Jamie introduces the topic of the biological basis of gender, addressing the misconception that gender is determined by environmental factors such as upbringing or parental influence. They clarify that gender has a strong biological basis supported by scientific evidence and refute the idea that gender is a socio-cultural construct or a passive response to one's anatomy. The video aims to define terms like 'sex' and 'gender identity' and promises to share studies that support the biological model of gender, which includes gender manipulation studies, twin studies, androgen exposure in utero, and brain anatomy studies.

05:01

👥 Studies on Biological Determinants of Gender Identity

This section delves into various studies that demonstrate the biological underpinnings of gender identity. It begins with gender manipulation studies, such as the one by Rainer and Gearhart in 2004, which involved genetic males with cloacal exstrophy who were surgically altered and raised as females but later identified as male, suggesting that gender identity is not a passive response to assigned sex or genitalia. Twin studies are then discussed, highlighting the high concordance rate of transgender identity among identical twins compared to fraternal twins, indicating a genetic component. The influence of androgen exposure in utero on gender identity is also examined, with examples of conditions like virilizing congenital adrenal hyperplasia and androgen insensitivity syndrome, showing that hormonal exposure can significantly impact gender identity development.

10:03

🧠 Brain Anatomy and Gender Identity

The final paragraph focuses on brain anatomy studies related to gender identity, specifically the research by Zhou et al. in 1995, which found similarities in brain patterns between trans women and cisgender women, suggesting that the brains of trans women are anatomically more aligned with their gender identity than their assigned sex at birth. The summary concludes by reinforcing the scientific consensus that gender identity is shaped by biological factors rather than environmental or socio-cultural influences. It also emphasizes that educating children about gender differences does not affect their gender identity but can reduce stigma and discrimination towards transgender individuals.

Keywords

💡Gender

Gender refers to the range of characteristics, behaviors, roles, and identities that a particular society considers appropriate for men and women. In the video, gender is discussed as having a strong biological basis, rather than being solely a social or environmental construct. For example, the script mentions that gender identity is not a passive response to one's anatomy or a product of parental influence.

💡Biological Basis

The biological basis of gender refers to the innate, natural factors that contribute to an individual's gender identity, such as genetic and hormonal influences. The video emphasizes that gender identity is not shaped by the environment but is instead rooted in biology, as evidenced by various studies mentioned in the script.

💡Gender Identity

Gender identity is a person's deeply-felt sense of being male, female, or something else, and may not necessarily align with their assigned sex at birth. The video discusses how gender identity is an enduring aspect of a person's self, which is not influenced by external factors such as upbringing or social expectations.

💡Sex

Sex, in the context of the video, refers to the biological and physiological differences between male and female individuals, typically assigned at birth based on physical characteristics. The script distinguishes sex from gender identity, noting that sex does not determine gender identity.

💡Intersex

Intersex individuals are those who are born with sex characteristics that do not fit typical binary notions of male or female bodies. The video mentions intersex as one of the categories that can fall under the term 'sex,' highlighting the diversity in biological sex.

💡Androgen Exposure

Androgen exposure refers to the level of androgens, such as testosterone, that a fetus is exposed to in the womb. The video discusses studies that link high levels of androgen exposure in utero to a higher likelihood of individuals with XX chromosomes later identifying as male, suggesting a biological influence on gender identity.

💡Twin Studies

Twin studies are research methods that compare the traits of identical twins (who share nearly all genetic material) with those of fraternal twins (who share about half). The video cites twin studies to demonstrate a genetic component in transgender identity, as identical twins are more likely to both identify as transgender compared to fraternal twins.

💡Gender Manipulation Studies

Gender manipulation studies involve cases where the assigned gender of individuals at birth was altered, often due to medical conditions. The video describes a study where genetic males with a malformation were raised as females, but most identified as male when they learned about their birth history, indicating that gender identity is not a result of upbringing or physical sex characteristics.

💡Brain Anatomy Studies

Brain anatomy studies examine the physical structure and organization of the brain. The video references a study that found similarities in the brain anatomy of trans women and cisgender women, suggesting that gender identity may have a neurological basis.

💡Androgen Insensitivity Syndrome

Androgen Insensitivity Syndrome is a condition where individuals have a genetic male (XY) makeup but do not respond to androgens, leading to the development of typically female physical characteristics. The video uses this condition as an example to illustrate that exposure to androgens can influence gender identity, as individuals with this syndrome, despite being genetic males, identify as female.

💡Gender Binary

The gender binary is the traditional cultural view that there are only two genders, male and female, and that each person must belong exclusively to one of these categories. The video argues that the gender binary is a social construct rather than a biological necessity, as gender identity exists on a spectrum.

💡Rapid Onset Gender Dysphoria

Rapid Onset Gender Dysphoria is a controversial term used to describe a supposed phenomenon where adolescents quickly develop gender dysphoria due to social influences. The video dismisses this idea as unfounded, emphasizing that gender identity is biologically determined and not influenced by peers or social trends.

Highlights

The biological basis of gender is a strong determinant, contrary to the belief that environment or parental influence can change gender identity.

Gender identity is not a passive response to one's anatomy but is likely established in utero.

Gender is a natural spectrum of biological diversity, not merely a socio-cultural construct.

Four main groups of studies support the biological basis of gender: gender manipulation studies, twin studies, androgen exposure studies, and brain anatomy studies.

Gender manipulation studies show that gender identity is not influenced by sex assigned at birth or parental rearing.

Twin studies reveal a high genetic concordance in transgender identity among identical twins.

Androgen exposure in utero influences gender identity, with higher rates of male identification in genetically female babies exposed to high levels of androgens.

Androgen insensitivity syndrome cases show that lack of androgen exposure leads to female identification, despite male genetics.

Brain anatomy studies indicate that the brains of trans women are similar to those of cisgender women.

Teaching children about gender differences does not influence their gender identity.

Educating children about gender can reduce stigma and improve acceptance of transgender individuals.

The concept of rapid onset gender dysphoria, suggesting peer influence, is refuted by scientific evidence.

Gender binary is a socio-cultural construct, not a biological one.

The study by Rainer and Gearhart in 2004 highlights the failure of gender assignment based on physical alteration and upbringing.

Halens et al.'s twin study emphasizes the genetic component in transgender identity.

Zhou et al.'s 1995 study on brain sex differences in relation to transsexuality provides evidence for biological underpinnings of gender identity.

The conclusion emphasizes the preponderance of scientific evidence supporting the biological factors of gender identity.

Transcripts

hey it's Dr Jamie I used AC pronouns

welcome back to the channel

so today I thought we would talk about

the biological basis of gender

why talk about this topic

many people still believe that gender

sexual orientation and other traits are

determined by the environment

for example that pure influence or

parental influence can somehow change

whether a child identifies as gay

straight trans not trans

the actual evidence shows that this is

very misguided

in reality gender has a very strong

biological basis and there's a lot of

evidence to support this and that's what

I will share today

okay

so I think we should start by just

defining a few terms

so the term sex or natal sex is what is

assigned at Birth

terms that fall under sex include male

female intersex

gender or gender identity describes

one's innermost perception as a man a

woman

something in between or neither

it is not always visible to others but

is enduring

our evolution in our understanding of

gender has changed dramatically over

time

long ago we thought that there was an

environmental influence that somehow a

rental rearing peer influences could

impact gender but in reality there's not

a lot of evidence to support that

there's actually evidence to refute it

many have said that gender is a

socio-cultural construct

there's actually very little evidence to

support this too although one could say

that gender roles and how one performs

gender could be defined within a

socio-cultural construct

others have proposed that gender is

simply a passive response to one's

Anatomy so if you look down and you see

male genitalia you identify as a man

that's also not the case and there's

evidence against this that I will share

then there is the biological model of

gender which really sees gender as a

natural spectrum of biological

exuberance and diversity and is a result

of neurophysiological and neural

anatomical development

and I will now share with you some of

the studies that support that

there are sort of four groups of studies

when you look at the biological basis of

gender those are gender manipulation

studies twin studies

studies of Androgen exposure in utero

and brain anatomy studies

so let's look at the gender manipulation

studies cases

so in this study by Rainer and Dear

Heart in 2004 called and now this name

is kind of difficult so just bear with

me discordant sexual identity and some

genetic males with cloacal estrophy

assigned female at Birth okay so what is

this study about

so there were 16 infants who were

genetic males XY chromosomes who had a

malformation of their gut and genitalia

all of these babies were surgically

modified to have female genitalia at

Birth and were reared as women

the idea was at the time that if you

raise these babies as women

and you give them female genitalia they

will identify as women

and they didn't

okay so all they were raised by women

eight declared unwavering male identity

four identified as male spontaneously at

ages 799 and 12. although two of their

parents persists persistently rejected

these declarations

four others identified as male after

their parents revealed their birth

history at ages five seven seven and

eighteen two subjects were weird as male

and identified themselves as male and

interestingly at the end of this study

all of the babies who knew their medical

history identified as male

so the conclusion from this study is

that gender is not a passive response to

sex assigned at Birth or genitalia and

or a product of Parental wearing gender

is biological and likely established in

utero again these kids were

altered physically at Birth were reared

as female and all of them who knew their

history when they got older identified

as male

which shows you that is the most

strongest amount of

like anatomical manipulation and

environmental influence and even then

these kids had a strong sense of gender

identity

Wild

okay twin studies so in this study by

halens at all titled gender identity

disorder and twins a review of the case

report literature

they looked at fraternal and identical

twins so fraternal

share like they don't share

like genetic material like

they both are in like uh separate eggs

or OVA

and then identical twins are in the same

age or OVA and have almost all the same

genetic material and so what they were

looking at in this study is that okay if

a fraternal twin identifies as trans how

often does the other twin identify as

trans versus identical twins okay

so when the fraternal twins got older if

one identified as trans none of the

other twins identified as trans okay

now with the identical twins if one

identified as trans

40 of the other twins identified as

trans now this is what we call High

concordance High genetic concordance

which whenever you see numbers like 40

that's really big which again implies

that there is a strong genetic component

to transgender identity which I think is

pretty cool

all right so what about hormone exposure

neutral and how that influences gender

identity there have been a few really

interesting studies done case studies on

individual and also larger studies so

these kind of come in I'll say two

groups so the first were some cases

looking at virulizing congenital adrenal

hyperplasia so these are

babies who are assigned female at Birth

they have

XX chromosomes they're genetic females

and they were exposed to like high level

Androgen so think testosterone in utero

five percent of those babies who are

exposed that high level of testosterone

identified as male later on

as they developed okay now compare that

to the general population where only

about one half to one percent of genetic

females later identify as male what this

shows is that at Androgen exposure in

utero seems to have a strong influence

biologically on gender identity later in

life

here's another example

so there are these um babies so this

condition is called Androgen

insensitivity syndrome so these are

genetic males X y's who have an

insensitivity to testosterone so meaning

even if testosterone is around their

bodies can't identify that signal so

because of that even though they're

genetic males they never develop male

genitalia when they're born they look

like little girls and they're usually

raised as little girls although they

don't have ovaries and you know a uterus

or any of that they but they do have a

vagina

in all cases these

I'm gonna say little girls who grow up

and later find out that they have

Androgen and Sensitivity Syndrome none

of them ever identify as male that all

identify as female

which shows that exposure to androgens

or the or the lack of exposure to

androgens seems to have a strong

influence or at least some influence on

gender identity later on

what about brain anatomy studies so this

is a really interesting study by Zao at

all done in 1995 and it's titled a sex

difference in the human brain and its

relations to transsexuality so this

group was actually studying

homosexuals or gays and uh they were

trying to see if there was a difference

between heterosexual men and homosexual

men

but what they actually found were

differences in

trans women and

uh CIS men

okay so when you look at the brain and

I'm going to like turn this over this

side so here's a heterosexual male over

here notice that the staining pattern is

very similar to the homosexual male so

almost no difference

but interesting what they found is that

so this is a CIS female

so someone who is assigned female birth

and identifies as a woman and a trans

female which actually I should say trans

woman so this is CIS woman and trans

women but um when you look at these you

do see that they look the same okay so

what that implies here is that

anatomically the brains of trans women

are similar to CIS women and that's

pretty cool

okay so what are the conclusions so

there's a preponderance of scientific

evidence that shows that gender identity

is a product of biological factors and

not a result of environmental or

socio-cultural influences nor is it a

passive response to sex a sign at Birth

the gender binary is a socio-cultural

construct not gender and gender identity

okay based on the biological nation of

gender there is no reason to believe

that teaching children about gender

differences would have any influence on

their gender identity let me say that

again

teaching children about gender

differences would have no influence on

their gender identity

educating children about gender may lead

to less stigma

fear

bullying hate and bigotry directed

towards transgender

children adolescents and adults

okay I hope that was helpful it's

um I think it's really important to

understand the basis of the scientific

evidence with all of these crazy ideas

out there like rapid onset gender

dysphoria which is the sort of idea that

kids are influenced by their peers and

they become trans it's all Malarkey all

right hopefully this was helpful I

enjoyed sharing it with you if you have

any questions please put them in the

comments below I appreciate you all

checking in and I look forward to seeing

you on the next video