David Reimer and John Money Gender Reassignment


  • David Reimer: David was born in 1965; he had a MZ twin brother. When he was 8 months old his penis was accidentally cut off during surgery.
  • His parents contacted John Money, a psychologist who was developing a theory of gender neutrality. His theory claimed that a child would take the gender identity he/she was raised with rather than the gender identity corresponding to the biological sex.
  • David’s parents brought him up as a girl and Money wrote extensively about this case claiming it supported his theory. However, Brenda as he was named was suffering from severe psychological and emotional difficulties and in her teens, when she found out what had happened, she reverted back to being a boy.
  • This case study supports the influence of testosterone on gender development as it shows that David’s brain development was influenced by the presence of this hormone and its effects on gender identity was stronger that the influence of social factors.

David Reimer was an identical twin boy born in Canada in 1965. When he was 8 months old, his penis was irreparably damaged during a botched circumcision.

John Money, a psychologist from Johns Hopkins University, had a prominent reputation in the field of sexual development and gender identity.

David’s parents took David to see Dr. Money at Johns Hopkins Hospital in Baltimore where he advised that David be “sex reassigned” as a girl through surgical, hormonal, and psychological treatments.

John Money believed that gender identity is primarily learned through one’s upbringing (nurture) as opposed to one’s inborn traits (nature). He proposed that gender identity could be changed through behavioural interventions, and he advocated that gender reassignment was the solution for treating any child with intersex traits or atypical sex anatomies.

He argued that it’s possible to habilitate a baby with a defective penis more effectively as a girl than a boy.

At the age of 22 months, David underwent extensive surgery in which his testes and penis were surgically removed and rudimentary female genitals were constructed.

David’s parents raised him as a female and gave him the name Brenda (this name was chosen to be similar to his birth name, Bruce). David was given estrogen during adolescence to promote the development of breasts.

He was forced to wear dresses and was directed to engage in typical female norms, such as playing with dolls and mingling with other girls.

Throughout his childhood, David was never informed that he was biologically male and that he was an experimental subject in a controversial investigation to bolster Money’s belief in the theory of gender neutrality – that nurture, not nature, determines gender identity and sexual orientation.

David’s twin brother, Brian, served as the ideal control because the brothers had the same genetic makeup, but one was raised as a girl and the other as a boy. Money continued to see David and Brian for consultations and check ups annually.

During these check-ups, Money would force the twins to rehearse sexual acts and inspect one another’s genitals. On some occasions, Money would even photograph the twins doing these exercises. Money claimed that childhood sexual rehearsal play was important for healthy childhood sexual exploration.

David also recalls receiving anger and verbal abuse from Money if they resisted participation.

Money (1972) reported on Reimer’s progress as the “John/Joan case” to keep the identity of David anonymous. Money described David’s transition as successful.

He claimed that David behaved like a little girl and did not demonstrate any of the boyish mannerisms of his twin brother Brian. Money would publish this data to reinforce his theories on gender fluidity and to justify that gender identity is primarily learned.

In reality, though, David was never happy as a girl. He rejected his female identity and experienced severe gender dysphoria . He would complain to his parents and teachers that he felt like a boy and would refuse to wear dresses or play with dolls.

He was severely bullied in school and experienced suicidal depression throughout adolescence. Upon learning about the truth about his birth and sex of rearing from his father at the age of 15, David assumed a male gender identity, calling himself David. He underwent treatments to reverse the assignment such as testosterone injections and surgeries to remove his breasts and reconstruct a penis.

David married a woman named Jane at the age of 22 and adopted three children.

Dr. Milton Diamond, a psychologist and sexologist at the University of Hawaii and a longtime academic rival of Money, met with David to discuss his story in the mid-1990s.

Diamond (1997) brought David’s experiences to international attention by reporting the true outcome of David’s case to prevent physicians from making similar decisions when treating other infants. Diamond helped debunk Money’s theory that gender identity could be completely learned through intervention.

David continued to suffer from psychological trauma throughout adulthood due to Money’s experiments and his harrowing childhood experiences. David endured unemployment, the death of his twin brother Brian, and marital difficulties.

At the age of thirty-eight, David committed suicide.

David’s case became the subject of multiple books, magazine articles, and documentaries. He brought to attention to the complications of gender identity and called into question the ethicality of sex reassignment of infants and children.

Originally, Money’s view of gender malleability dominated the field as his initial report on David was that the reassignment had been a success. However, this view was disproved once the truth about David came to light.

His case led to a decline in the number of sex reassignment surgeries for unambiguous XY male infants with a micropenis and other congenital malformations and brought into question the malleability of gender and sex.

At present, however, the clinical literature is still deeply divided on the best way to manage cases of intersex infants.


Colapinto, J. (2000). As nature made him: The boy who was raised as a girl. New York, NY: Harper Collins.

Colapinto, J. (2018). As nature made him: The boy who was raised as a girl. Langara College.

Diamond, M., & Sigmundson, H. K. (1997). Sex reassignment at birth: Long-term review and clinical implications. Archives of pediatrics & adolescent medicine, 151(3), 298-304.

Money, J., & Ehrhardt, A. A. (1972). Man & Woman, Boy & Girl: The Differentiation and Dimorphism of Gender Identity from Conception to Maturity. Baltimore, Maryland: Johns Hopkins University Press.

Money, J., & Tucker, P. (1975). Sexual signatures: On being a man or a woman.

Money, J. (1994). The concept of gender identity disorder in childhood and adolescence after 39 years. Journal of sex & marital therapy, 20(3), 163-177.

Saul Mcleod, PhD

BSc (Hons) Psychology, MRes, PhD, University of Manchester

Educator, Researcher

Saul Mcleod, Ph.D., is a qualified psychology teacher with over 18 years experience of working in further and higher education.

Julia Simkus

Research Assistant at Princeton University

Undergraduate at Princeton University

Julia Simkus is a Psychology student at Princeton University. She will graduate in May of 2023 and go on to pursue her doctorate in Clinical Psychology.