Early in this century, neuroanatomists and neurophysiologists began to look for places and functions in the brain that were different in transgender people from non-transgender people. The results of their efforts indicate that there are several structures and mechanisms that are different, some of which can be interpreted.  Finding such differences supports the four factor theory of transgender causation, in that, the theory predicts that genetic gender behavior predispositions exist in the brain and can be detected in its structure and mechanisms. 

The Transgender Scientist

Transgender Neuroanatomy and Neurophysiology

Transgender Transition: Breast Enhancement Surgery. This episode explains why transitioning transwomen go on hormone therapy and why breast enhancement surgery is often needed.  Transwomen want to look like other women and wear feminine clothing but this requires hormone therapy to reshape the body and, in particular the breasts.  When hormone therapy results for breast development is inadequate, about half of transitioning transwomen get breast implants for enhancement.  The episode also describes what it was like for your Transgender Scientist to get breast enhancement surgery. 

Transgender Transition: Breast Enhancement Surgery

This episode provides a critical review of the recent by Lisa Littman of Brown University which claims that gender dysphoria originates in childhood trauma and can be triggered by information "contagion" from peers and the Internet in adolescence.  The episode also provides the historical and scientific on background on this claim which indicates that it constitutes a non-scientific attack on affirmative treatment for transgender children and adults.  The paper involved a survey, ostensibly from surprised and disgruntled parents which was used to claim based on flawed methodology that their children were not dysphoric in childhood but became dysphoric in adolescence. Littman cannot prove that the children were gender dysphoric because the parents were not asked about a critical criterion of debilitation and distress which is required for gender dysphoria and typically is used as a billing code for transgender transition. Two results were described which support hypotheses for more rigorous study: (1) because the transgender children had been diagnosed with anxiety and depression it is possible that this resulted from living in secrecy as being transgender from earlier childhood  (2) because parents of natal female children were surprised by the emergence of their children as being transgender but were not surprised by earlier declarations of lesbian, bi or sexual orientation, the children may have deliberately come out with declarations of alternative sexual orientations that were more socially correct to prepare their parents for transgender emergence. 

Rapid Onset Gender Dysphoria: An Attack on Affirmative Transgender Treatment

Transgender history to the 1980s.  This episode traces development of and advocacy for transgender demographic groups from the turn of the 20th Century to the 1980s.  Advocacy organizations were built for three demographic groups of transgender people (1) those who wanted to change their bodies, previously called transsexuals who were championed by the medical and mental health communities (2) non-transsexual transgender people who developed local peer-led support groups, spawning transgender conventions (3) transgender people forced to live on the street because their transgender behavior was rejected at home. These developments were independent but loosely connected through activities in San Francisco and by a transwoman named Louise Lawrence. 

Transgender history to the 1980s

This episode tells you what you need to know to have effective and productive conversations with transgender people.  As in conversations with other types of people, the intent is not to offend. But transgender people are different; so you need to know the difference.  There are words and terms that hurt transgender people as well as using the wrong pronouns.  Misgendering a transgender person creates a hostile work environment that has legal liability.  There are several questions that transgender people will frankly not answer and knowing the reasons why is important. 

Transgender Etiquette for Effective Communication

It is revealed that the idelogy of Ryan Anderson and Paul McHugh is heterogenderism. Real science regarding some of the topics of Anderson's book When Harry Became Sally are presented.   Heterogenderism seeks to debase transgender people by saying that they are abnormal or mentally ill.  Anderson and McHugh seek to equate sex and gender which denies the existence of transgender people.  The combination of heterogenderism and populism results in public policy that discriminates against transgender people and gaslights them by constantly referring to them as inferior. 

Heterogenderism: Harry Was Already Sally

How many transgender people are there? Until the year 2000 we only had estimates from medical clinics which grossly understated the population frequencies of being transgender, being transsexual and transgender genital plastic surgery.  In 2000, the first mathematical estimation models were constructed using data and the results were surprising.  Since then they have been confirmed by surveys in which being transgender is asked directly or can be inferred from health surveys.  But the fate of future US government surveys is in doubt.  Transgender people will not be counted in the 2020 US Census and questions identifying transgender people have been stripped from important surveys.  So what is the best current scientific estimates available?

How Many Transgender People Exist?

Previous podcasts provided information on the factors involved transgender causation.  Transgwender emergence usually occurs in childhood. This podcast continues from childhood transgender emergence.  What happens to these kids? One of the new opportunities for transkids is affirmative therapy including the Netherlands protocol that allows them to delay puberty so that they can decide about their adult gender. The episode also provides scientific information on the issue as to how long does being transgender continue from childhood into adulthood.  Critics of affirmative therapy and the Netherlands protocol say that transkids will naturally stop being transgender as adults so that there is no point in providing affirmative therapy. This episode provides a review of the science about continuance of being transgender into adulthood. 

Science of Transkids and Continuance of Transgender Behavior

This episode provides information on the fourth factor in transgender causation--that o early childhood learning and transgender recognition. Most all children know the basics of the Western gender system including the two gender behavior categories by age 2-3.  They come to recognize which one fits with their genetic gender predisposition.  In the case of transgender children, the category which fits them is not the same as the one they were assigned at birth on the basis of sex assignment. This is not a conscious lifestyle choice.  Like most choices, it involves subconscious processes of which we are not aware. We become consciously aware only after the choice has been made. As for lifestyle, the alternative gender behavior categories are determined by culture, not by biology. 

Transgender Causation Factor 4: Childhood Learning and Transgender Recognition

Culture is the third factor in transgender causation. In earlier podcasts I described how genetic gender predisposition was formed based on two factors: genetics and epigenetics.  In this podcast I describe why culture is the third factor in being transgender.  It appears that being transgender only occurs in Western culture.  Western culture is peculiar among those cultures that have been studied. It has the peculiar characteristics of being binary, cisgender and inflexible.  When genetic gender predisposition and culture collide, the result is transgender people. Examples of other cultures that have up to 5 gender behavior categories, that are not cisgender and are not inflexible. Transgender people cannot change their genetic gender predisposition but they can change Western culture to be more accomodating to diversity. 

Culture: Third Factor of Transgender Causation

Prenatal Testosterone Theory of Transgender (PTTT) Causation: Origins and Evidence.  Do low prenatal testosterone levels in males and do high prenatal testosterone levels in females cause being transgender? The origins of this theory in eugenics and the evidence refuting the theory.  The PTTT is rooted in eugenics theory developed in the US during the first half of the 20th Century.  With support from private foundations, eugenics developed and spread to Germany and Europe.  After World War II, East Germant eugenic endocrinologists developed the PTTT as the way to get rid of transgender people in society by adminstering drugs to pregnant mothers.  If a mother was carrying a male baby, testosterone booster shots were recommended; if a mother was carrying a female baby, testosterone blockers were advised.  The scientific evidence refutes the PTTT.

Epigenetics: The Prenatal Testosterone Theory of Transgender Causation

This episode reviews the evidence for the prenatal estrogen theory of being transgender in natal males. Since estrogen does not readily penetrate the brain, the evidence cited for the estrogen theory involves the synthetic chemical diethylstibestrol or DES. This drug was given to pregnant females during 1940's through the 1980's but was eventually banned because it caused cancer in female offspring who were exposed through their mothers in utero.  Because of this, most of the research was conducted with exposed natal females.  Research with exposed males was initiated by DES-esposed researchers who believed that they were affected to become transgender. They started a website for DES exposed males and found that 150 of the 500 males who joined the website thought that they were transgender.  This episode provides an answer as whether the evidence supports whether DES causes being transgender and the status of the estrogen theory of being transgender.

Epigenetics: The Estrogen Theory of Transgender Causation in Natal Males

This podcast covers for transgender genetic gender behavior predisposition in the form of biomarkers and "natural experiments." Biomarkers include handedness, 2D4D finger length ratio and FTM anatomy.  Natural experiments include the saga of David Reimer and the effects of raising males with cloacl extrophy in the feminine gender behavior category. 

Transgender Biomarkers and Natural Experiments

Two new papers have been published that conclusively demonstrate the genetics of gender predisposition.  In this podcast, the Transgender Scientist will provide information on these new studies and what they mean. 

Breaking News: Genetic Gender Predisposition Breakthroughs

Factors in transgender causation.  Why are people transgender? Dana Bevan, The Transgender Scientist identifies 4 factors. They involve genetics, epigenetics, Western culture, and early childhood learning.  This episode provides a top-level description of the 4 factors which will be detailed in subsequent episodes. 

The science factors that create transgender people.

Science applied to current transgender issues. Hosted by Thomas (Dana) Bevan, who holds a Ph.D. in biopsychology and has authored 3 books on trans science.

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The Transgender Scientist

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