Gender

What determines gender? Is it genes?

Aidan Key FTM, Chair of FTM 2001 with his identical twin sister

One in every 50 children are born with a blended neurological gender, 2% of the overall population are gender variant. One in every 200 children are born having a neurological gender opposite to that indicated by their genes and anatomy and transition to living in their neurological male gender (FTM female-to-male) or female gender (MTF male-to-female) with or without hormones and surgery. One in 13,000 births an XY (genetic male) fetus is born that is unresponsive to fetal male hormones, and develops female anatomy, except for a lack of internal reproductive organs. The existence of XY (genetic male) infants who have female anatomy and who grow up to have female gender identity (complete Androgen Insensitivity Syndrome females), led scientists years ago to recognize that gender identity IS NOT determined directly by having XY or XX genes.

Juan Barbachano with his identical twin sister. (ABCNEWS)

Twin Offers New Insight Identical Female Twins Become Sister and Brother
Oct. 23, 2004 — While many people would assume that identical twins are exactly alike, Liana and Juan Barbachano are showing the world that in some cases, they couldn't be more different.
Juan Barbachano was born as Juanita. Juanita began to realize that she and her twin sister felt very differently about themselves. When the two played house, Juanita always wanted to be the daddy, never the mommy. And when Juanita went to bed on Christmas Eve, she wished Santa would help her wake up as a boy. Juanita felt as if she was a boy trapped inside of a girl's body
At age 4, Juanita chopped off her long hair and wore pants as much as she could. In high school, she joined the football team and asked her teammates to call her "Juan." Now 35, Juan says life has improved with hormone therapy and surgery, and with the support of a loving sister.
"I'd been told that, you know, God doesn't want me to do this. Something's wrong with me, I'm sick. But then I came to realize that God made me the way I am and he loves me just the way I am," Juan said on ABC News' "Good Morning America." "I never expected to receive the support and love I have received from Liana.
Nancy Segal, a professor of developmental psychology and director of the Twins Study Center at California State, Fullerton, says Juan's experience is helping researchers understand twins better.
"From what Juan and Liana tell us, genes do not predict identical behaviors," she said.
Doctors think that something happened in the womb that made the twins different.
"Juan was exposed to higher levels of testosterone male hormone, which redirected her brain, making her feel like a man. This did not happen to her sister, who grew up as a full female," Segal said.
Segal, author of "Entwined Lives: Twins and What They Tell Us About Human Behavior," says scientists are beginning to look at what happens to identical twins within the womb to explain similarities and differences that surface later in life.
"The womb is a very different experience for identical twins, and in some ways it's surprising that identical twins are as alike as they are," Segal said. "Gender is a complicated behavior affected by many things. Even with identical twins, who are so alike in many ways, as Juan and Liana are, there still can be profound differences between them."
After a long struggle, Juan's parents have come to terms with his gender and have decided to look beyond that one aspect of his life.
"When you look at a person in-depth, you're looking at a person, a being, not simply a man or a woman," said Juan's father, Joaquin Barbachano.

What determines gender? Is it anatomy? Is it upbringing?

XY males who had missing male anatomy as infants (cloacal exstrophy syndrome) and who had been surgically turned into females and raised as females, were followed up on: all developed MALE gender identities. Many of these males have since undertaken hormonal and social gender reassignment from female to male. The New York Times Bestseller As Nature Made Him: The Boy Who Was Raised As A Girl is a book about David Reimer, an identical twin whose male anatomy was removed as a result of a medical accident. In spite of not having male anatomy and in spite of upbringing as a girl, he transitioned from female to male and married and became a father to his wife's three children.

David Reimer A book about how Brenda became David Reimer 1965-2004

What determines gender? If it isn't the genes that determine gender (complete Androgen Insensitivity Syndrome girls have XY genes but are female), and if it isn't anatomy or upbringing that determine it (cloacal exstrophy boys have female anatomy and upbringing but are male), then what determines a person's gender?

Gender is determined by neurology. Structures are "hard-wired" prenatally in the lower brain centers during the early stages of pregnancy, during a hormonally-modulated imprinting process in the central nervous system. If the brain and central nervous system are masculinized in early pregnancy by hormones in the fetus, then the child will have a male gender identity, independent of whether the genes or anatomy are male. According to William Reiner, M.D., pediatric clinician and researcher at The Johns Hopkins Hospital, based on his Cloacal Exstrophy follow-up study, what determines gender is "not the external genitalia, but the brain." [William Reiner, M.D., To Be Male or Female--That is the Question, 151 Arch Pediatr. Adolesc. Med. 225 (1997)]. Gender is irreversible by psychological treatment, because psychotherapy cannot change neurology.

In every society throughout history trans individuals have led distinguished and historically significant lives.

Our Contributions | FTM HIStory | FTM Contributions to Art, Architecture and Photography | FTM Contributions to Literature and Journalism | FTM Contributions to Performing Arts, Music, Drama and Film | FTM Contributions to Medicine, Psychology and Science | FTM Contributions to Business, Government, the Military and Law | FTM Contributions to Education and Spirituality

Back to Mens World

Last Modified