In 1965, a circumcision accident destroyed the penis of an eight-month-old Canadian boy named Bruce Reimer, setting in motion one of the most controversial experiments in the history of medicine. On the advice of Johns Hopkins psychologist John Money, Bruce’s parents agreed to have their son surgically reassigned as female and raised as a girl named Brenda. Money presented the case to the world as proof that gender identity is entirely learned, but the child never accepted the female role forced upon him. After discovering the truth as a teenager, he transitioned back to living as male under the name David Reimer. He took his own life in 2004 at the age of 38.
The Accident and the Decision
Bruce Reimer and his identical twin brother Brian were born in Winnipeg, Manitoba, in August 1965. At roughly seven months of age, both boys were referred for circumcision to treat a condition called phimosis. During Bruce’s procedure, the electrocautery device malfunctioned and severely burned his penis beyond surgical repair. His twin brother’s procedure was cancelled. The family was left with a healthy infant boy who had suffered catastrophic genital damage through no fault of their own.
Bruce’s parents, Ron and Janet Reimer, searched for answers. They eventually saw John Money on television discussing his work at Johns Hopkins, where he had become a prominent advocate of the idea that gender identity is primarily shaped by upbringing rather than biology. Money recommended that Bruce be surgically reassigned as female and raised as a girl. The infant underwent an orchiectomy and early-stage vaginoplasty, and the family renamed the child Brenda.1PubMed Central. Paternalism in DSD Management: A Real and Present Threat
Money’s reasoning hinged on a theory he had championed throughout the 1950s and 1960s: that children are psychosexually neutral at birth and that consistent socialization as one gender or the other, reinforced by the appropriate genital anatomy, would produce a stable gender identity. Bruce’s case was unique because he had an identical twin who would serve as a natural control. If Brenda thrived as a girl while Brian developed normally as a boy, Money would have powerful evidence that nurture, not nature, determined gender.
Growing Up as Brenda
Money published reports through the 1970s describing the case as a success. In academic papers and media appearances, he claimed that Brenda had adjusted well to her female role and that the twins were developing along typically gendered lines. The case, often called the “John/Joan” case in the literature, became one of the most widely cited examples in psychology, sociology, and women’s studies courses. Textbooks treated it as near-definitive evidence that gender is socially constructed.
The reality inside the Reimer household was starkly different. Brenda rejected dolls, preferred roughhousing with her brother, tore off dresses, and resisted her parents’ attempts to steer her toward feminine activities. Classmates bullied her relentlessly because her appearance and behavior did not match what they expected of a girl. She was deeply unhappy and grew increasingly resistant to the annual visits to Money’s clinic at Johns Hopkins, where she and Brian were subjected to sessions that both later described as psychologically abusive. These sessions reportedly included having the children inspect each other’s genitals and simulate sexual positions, which Money considered therapeutic reinforcement of gender roles. Both twins found the visits traumatic.
By adolescence, the situation was deteriorating rapidly. Brenda was prescribed estrogen to induce breast development, but she was profoundly uncomfortable with the physical changes. She had no interest in dating boys. School became unbearable, and she experienced severe depression and suicidal thoughts. Local psychiatrists who worked with the family grew increasingly uneasy with Money’s approach, but his professional authority and the family’s desperation kept the plan in place for years longer than it might otherwise have survived.
The Truth Comes Out
When Brenda was around fourteen, her father Ron told her the full story of what had happened. By Brenda’s own later account, the revelation was both devastating and clarifying. Almost immediately, she began the process of transitioning back to living as a male. She chose the name David, stopped taking estrogen, and began testosterone therapy. He underwent a double mastectomy and later had phalloplasty surgery to reconstruct male genitalia.
David eventually married a woman named Jane and adopted her three children. But the psychological scars of his childhood never fully healed. He struggled with depression and financial difficulties throughout adulthood. His twin brother Brian, who had his own history of mental health problems compounded by the family’s turmoil, died of an overdose of antidepressants in 2002. Two years later, on May 4, 2004, David Reimer committed suicide.1PubMed Central. Paternalism in DSD Management: A Real and Present Threat
How the Scientific Record Was Corrected
For nearly two decades, Money’s version of events went essentially unchallenged in the academic literature. He continued to cite the case as evidence for his theory of psychosexual neutrality, and few researchers had access to the family to verify his claims. That changed in the mid-1990s when sexologist Milton Diamond, who had long been skeptical of Money’s framework, tracked down David Reimer and psychiatrist Keith Sigmundson, who had treated David in Winnipeg.
In 1997, Diamond and Sigmundson published a follow-up in the Archives of Pediatrics and Adolescent Medicine that demolished Money’s narrative. Their report confirmed that the individual had rejected the female sex of rearing, had switched to living as a male at puberty, and had successfully lived as such since that time. They explicitly recommended that the standard practice of reassigning boys with severe genital damage as female be reconsidered in light of the new evidence.2PubMed. Sex reassignment at birth. Long-term review and clinical implications
The following year, journalist John Colapinto published a long article in Rolling Stone magazine that brought David’s story to a general audience for the first time. Colapinto later expanded the piece into a book, As Nature Made Him: The Boy Who Was Raised as a Girl, published in 2000. David cooperated with Colapinto because he wanted other families to know what had really happened and to prevent similar decisions from being made about other children.
Money never publicly acknowledged that the case had failed. He attributed the outcome to the family’s inconsistent commitment to raising Brenda as a girl and to interference from local clinicians. He continued to defend his broader theoretical framework until his death in 2006. The scientific community, however, largely moved on. The Reimer case went from being a cornerstone of gender-as-socialization theory to being one of the most cautionary examples of ideology overriding evidence in modern medicine.
What Biology Research Has Shown Since
The Reimer case did not single-handedly resolve the question of how gender identity develops, but it cracked open a door that researchers have since walked through with substantial evidence. One of the most productive lines of inquiry has involved girls with congenital adrenal hyperplasia (CAH), a genetic condition that exposes female fetuses to unusually high levels of androgens in the womb. These individuals are genetically female but experience hormonal environments during fetal development that more closely resemble those of typical males.
Research on girls with CAH has consistently found that prenatal androgen exposure shifts behavior in a male-typical direction. They tend to show increased preference for rough-and-tumble play, greater interest in toys typically preferred by boys, and higher rates of physical aggression. These patterns emerge early in childhood, well before social expectations could plausibly account for them.3PubMed Central. Early androgen exposure and human gender development Broader research on individuals exposed to atypical hormone concentrations prenatally, whether through genetic conditions or maternal hormone treatment during pregnancy, has found similar shifts in play behavior, sexual orientation, and gender identity itself.
More recent work has moved beyond behavioral measures to brain structure. A 2025 study published in Brain Communications found that females with CAH showed significantly more male-typical brain anatomy than control females, while males with CAH did not differ from control males. The researchers interpreted this as evidence that prenatal androgen exposure has lasting effects on the developing brain that persist into adulthood.4Brain Communications. Enduring prenatal androgen effects on the female brain
The picture is not as simple as “hormones determine everything.” Socialization clearly matters too. Research on CAH girls has shown that prenatal androgen exposure changes how girls respond to social cues about gender-appropriate behavior. Specifically, they are less responsive to information indicating that certain objects are “for girls” and show reduced imitation of female models. In other words, the biological influence appears to work partly by altering how children absorb and act on gender-related social information, not just by hardwiring preferences directly.5PubMed Central. Prenatal androgen exposure alters girls’ responses to information indicating gender-appropriate behaviour Biology and socialization intertwine rather than operating as separate levers, but the biological component is real and cannot be overridden simply by raising a child as one gender or another.
How the Case Changed Medical Practice
Before the Reimer case was exposed, the standard clinical recommendation for infant boys who suffered severe penile damage was to reassign them as female. The logic was straightforward under Money’s framework: a child could not grow up to live a satisfying life as a male without a functioning penis, so it was better to construct female anatomy and raise the child as a girl. Surgeons and endocrinologists at major pediatric hospitals worldwide followed this protocol for decades.
Diamond and Sigmundson’s 1997 paper directly challenged that standard, recommending that subsequent cases be managed differently in light of the evidence that reassignment had failed catastrophically.2PubMed. Sex reassignment at birth. Long-term review and clinical implications The ripple effects extended well beyond cases of accidental genital injury. Physicians managing infants born with differences of sex development (DSD), the current clinical term for conditions in which chromosomal, gonadal, or anatomical sex does not follow the typical male or female pattern, also began to question the longstanding practice of performing early “normalizing” genital surgery on ambiguous genitalia.
In 2006, a landmark consensus statement from an international group of clinicians and researchers attempted to codify new standards for DSD management. The statement acknowledged the controversy around early genital surgery but stopped short of a blanket prohibition. Consensus was reached that genital surgery for infants with significant ambiguity could proceed when parents clearly desired it, though the group could not agree on deferring all surgery until the child was old enough to participate in the decision. The lack of long-term outcome data made it difficult to set firm rules.6PubMed. Consensus statement on terminology and management: disorders of sex development
The tension has not gone away. Advocacy groups led by intersex adults who underwent childhood surgery have pushed for bans on medically unnecessary procedures, arguing that parents and physicians should not make irreversible decisions about a child’s body before the child can weigh in. Several countries, including Germany and Malta, have enacted legal protections. In the United States, the debate continues at the state level. Scholars have noted that the broader rise of bioethics and informed consent doctrine in the postwar era should theoretically have protected these children’s autonomy, but in practice those principles collided with a medical culture that favored early intervention on infants who could not consent.7Oxford Academic. Did Bioethics Matter? A History of Autonomy, Consent, and Intersex Genital Surgery
Money’s Complicated Intellectual Legacy
John Money is often portrayed as a villain in retellings of the Reimer story, and his conduct in that case warrants the criticism. But his influence on how we think and talk about gender is far broader and more tangled than one case study. Money is credited with coining the term “gender” as distinct from biological sex in the 1950s, creating the conceptual vocabulary that feminist scholars and gender theorists would later adopt. Paradoxically, Money himself resisted the uptake of his terminology by feminists, whose conclusions about gender often diverged from his own.8University of Chicago Press. Fuckology: critical essays on John Money’s diagnostic concepts
The Reimer case was initially heralded by many as proof that gender is pliable, a blank-slate argument that resonated with certain strands of feminist thought in the 1970s. When the case was discredited, it complicated that narrative without fully resolving the broader debate. Gender identity clearly has a biological substrate that cannot be wished away by socialization, as the CAH research and David Reimer’s own life demonstrate. But that does not mean gender is entirely fixed by prenatal hormones either. The vast majority of children develop a gender identity that aligns with their anatomy without any deliberate intervention, which makes it hard to disentangle what biology, socialization, and individual variation each contribute in typical development. The Reimer case illuminated what happens when the biological and social signals are dramatically forced apart, and the answer was suffering.
Why David Reimer’s Story Still Matters in Clinical Ethics
The Reimer case is sometimes reduced to a simple morality tale about nature versus nurture, but the deeper lesson is about what happens when a clinician’s theoretical commitments overpower the evidence in front of them. Money had staked his career on the idea that gender could be assigned. When the data from his most famous case contradicted that idea, he suppressed the contradictions rather than revising his position. Peer review failed because Money controlled access to the family and published selectively. Institutional oversight failed because Johns Hopkins deferred to Money’s authority. And the family suffered because they trusted the expert in the room.
The paternalism at the heart of the case, where physicians made irreversible decisions about a child’s body and identity based on an unproven theory, has become a focal point in ongoing debates about pediatric medical ethics. The question of when and whether adults should authorize life-altering interventions on children who cannot yet articulate their own preferences is now central to discussions about intersex surgery, and it echoes in debates about other pediatric treatments where long-term outcomes are uncertain.1PubMed Central. Paternalism in DSD Management: A Real and Present Threat
David Reimer agreed to go public with his story because he wanted to protect other children from what he had endured. In the years since, his case has been cited in medical ethics curricula, in legal arguments against non-consensual surgery, and in the clinical guidelines that now urge caution where Money urged confidence. The cost of that influence was borne almost entirely by one family in Winnipeg, and the weight of that fact is not something the scientific literature captures particularly well.