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  • Writer's pictureAmos Gdalyahu

The Tragedy of David Reimer and the Role of Genetics in Sexual Orientation and Identity

Updated: Feb 21

The tragedy began with an accident during Bruce's circumcision, which resulted in significant damage to his genitalia. The damage was so severe that experts recommended Bruce's parents, who were terrified, to change his sex to female! This meant surgical construction of a vulva in place of the damaged penis and, during adolescence, the administration of estrogen, the female hormone responsible for, among other things, breast development and analogous to male testosterone Remember, that anyway the baby practically didn't have a penis after the accident.

Indeed, a year and a half later, Bruce became Brenda, grew up as a girl, and was unaware of what had happened to him/her.

This was late in the 60s, and a well-known psychologist named Dr. Money, with a specialization in sexual identity, accompanied the case of Bruce/Brenda. Dr. Money has had huge impact on the field of gender. In fact, he is the one who actually coined the terms sexual identity and gender role. His belief was that gender identity is acquired, meaning it is learned rather than innate, or in other words, not genetically determined. Dr. Money was recognized with numerous awards, published around 2,000 articles, books, and even a textbook in which the case of Bruce/Brenda served as an example of the success of his approach: that gender identity is learned.

From Dr. Money's perspective, this was a perfect case to test his theory: Brenda/Bruce had an identical twin brother named Brian. This fact made it possible to see what happens when twins who are both males in terms of their genes, because they are genetically identical, grow up in the same environment, but one grows up as a girl (even though she is genetically male) and the other grows up as a boy. Dr. Money reported that, in accordance with his theory (so surprisingly), Brenda grew up to be a happy and normal girl. The story of Dr. Money about Brenda/Bruce gained widespread public attention and influenced policies in such cases. Indeed, the case seemed to prove that male/female behavior is determined by the environment and the way it relates to the child. A boy raised as a girl would become a girl.

Only in 1997 (!), it was revealed that Dr. Money did not tell the whole truth: Brenda's behavior was that of a tomboy, she disliked wearing dresses and playing with girls' toys. The other children teased her and called her "cave-woman". Already in second grade, she felt like she was a boy. Later, Brenda was sexually attracted to other girls, and all of this without knowing what happened to her as a baby named Bruce. She claimed that she was a boy trapped in a girl's body.

At age 12, she began taking estrogen, which helped her appearance look more feminine, but it did not change her feeling that she was a boy. So, at the age of 14 (1980), she stopped living as a girl and began living and dressing like a boy. Therefore, her parents decided to tell her the truth and she immediately requested a sex reassignment surgery. Indeed, this happened and Brenda (who was born as Bruce) became David. David Reimer.

Dr. Money did not publish this twist in the story, and this remained unknown until 1997. It created the mistaken impression that such surgery was successful, and such surgery was performed on thousands of other babies for various reasons!

David (who was Bruce and then Brenda) lived as a married man and later divorced. He suffered from depression, and ultimately, in 2004, at the age of 38, he committed suicide.

If it's not shocking enough, here are some more details:

  • The circumcision was done for medical reasons: the twins were born with a skin problem on the foreskin that disturbed urination and it was decided to remove it in surgery. For some reason, the doctor chose to remove the foreskin with electric cauterization instead of a surgical knife. After the terrible outcome, the parents left the second twin, Brian, with the problematic foreskin, which eventually resolved on its own. Meaning the whole tragedy wasn't even necessary.

  • The famous psychologist, Dr. Money, believed that children's play is a way for them to learn sexual functioning (?). Thus he justified why he caused the brothers to play with each other in sexual games in which they examined each other's genitals, and in which the twin male brother was asked to play as if he was having sexual relations with Brenda (!?!). The brother eventually developed schizophrenia and ultimately committed suicide two years before David's suicide. The parents blamed Dr. Money for the suicides of their two sons. (The post continues below).

The twin brothers a short time before they heard the truth about Brenda. From: "Neuroscience: Exploring the Brain", Fourth Edition by Mark F. Bear, Barry W. Connors, Michael A. Paradiso (2015).

This is a very disturbing and sad story that actually supports the exact opposite of Dr. Money's theory: genetics (nature) had a much greater impact than the environment on sexual and gender identity. In other words, raising someone up not according to what they are as in 'conversion therapy' would not work. Education didn't change sexual identity and orientation, biology triumphed. Usually, people with xy chromosomes are men and those with xx are women, but see below and see my post here in which I mention intersex cases. We are still far from a full understanding of the biology underlying sexual orientation and identity. Therefore, and as this story illustrates, it's very dangerous to enforce on someone our ideology on these issues and pretending it's all scientifically proven. Since the subject is politically and emotionally charged, I'm adding here a bit more science. The development of the sexual organs occurs between weeks 6 and 12 of a pregnancy. However, the sexual development of the brain occurs only a month and a half later. This is when sexual identity (the feeling of being male or female) and gender-typical behavior are determined, for example, girls tend to play more with dolls (probably as a way to prepare them for being moms). In addition to sexual identity, sexual orientation also develops on that time and it's not the same. For instance, someone may feel male, and their sexual orientation will be towards males. We know that genetics plays a significant role in determining sexual orientation and identity, but the details are still unknown. In summary, there are three separate pathways that are typically aligned with each other to create: sexual organs, sexual identity, and sexual orientation. However, biological changes can affect any of these pathways independently of the others, resulting in a lack of alignment.

In the case of David Reimer, he was raised as a girl, but there was only an external biological change. Therefore, his sexual identity and his sexual orientation were not affected, and they remained male. (David wore boys clothes, felt as a boy, and was attracted to girls). Education didn't change that. In contrast, if a biological change occurs after week 12 of a pregnancy, only the brain is affected while the genitals aren't affected. I'll review now some known examples for biologically-driven misalignments between the three: genitals, identity and orientation.

Embryos with XY chromosomes but with a mutation that makes them unresponsive to testosterone all along the pregnancy instead of developing as males develop female sexual organs, female sexual identity, and typically feminine tendencies. However, during puberty, the hormone that influences the development of masculine physical features is estrogen for which they are responsive (the mutation is in the receptor for testosterone). Therefore the body of the affected individual suddenly becomes more masculine (their clitoris grows significantly, their voice deepens, their appearance becomes more masculine, and body-hair develops). That is a case of misalignment or inter-sex. The opposite case is less dramatic: Sometimes, individuals with XX chromosomes are exposed during pregnancy to slightly higher levels of testosterone (though not as high as in males). From a physical perspective, they usually will develop an internal female reproductive system (ovaries, uterus, and no testes nor scrotum), but the clitoris may be enlarged to the point that parents sometimes mistakenly think they have a son! (The outer labia are enlarged, and the parents mistakenly perceive them as a scrotum). However, during puberty, their 'son' will continue to develop as female (to the astonishment of the family). In terms of their brain, exposure to higher levels of testosterone during pregnancy causes (only?) about 2% of these xx girls to develop a male sexual identity (Note that 2% is still way more than in the general population showing that testosterone during pregnancy plays a role in sexual identity. Maybe higher levels of testosterone would increase the number, and probably there are other factors).

It is important to remember that we do not fully understand the bio-development of sexual identity and sexual orientation in the brain. Therefore, there may be additional changes in unknown factors that cause individuals to experience a mismatch between their bodies, their sexual orientation, and their sexual identity. Currently, we cannot perform a genetic test to determine sexual identity or sexual orientation. This is a very complex topic, and it is important to be cautious and not take the science too far. Otherwise, the implications can be tragic.

But beyond the academic conclusions about what determines sexual and gender identity, the story of the Reimer's brothers is simply a very sad story. In reference #6 you can see David and his mom in a BBC documentary.

Are you interested in understanding the science of sexuality with an emphasis on neuro-science? I do, and therefore I've created a course - 5 meetings of about 2 hours each - dedicated to teaching Neuro-Sexuality. See here:

Update: There is an extremely rare condition called Aphalia, in which a male baby is born with a scrotum but without a penis. The urethra leads to the perineum. It is possible to create a functional penis through a complex medical process, but parents are also given the option to create a vulva followed by hormone therapy with estrogen. As this post demonstrates, the recommendation, these days, is to create a penis.


1. Gaetano, Phil, "David Reimer and John Money Gender Reassignment Controversy: The John/Joan Case". Embryo Project Encyclopedia (2017-11-15). ISSN: 1940-5030

2. Neuroscience: Exploring the Brain, Fourth Edition by Mark F. Bear, Barry W. Connors, Michael A. Paradiso (2015)

3. David Reimer Wikipedia -

4. Dr. John_Money Wikipedia -

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