This is not a pioneering study done in the field, jfc. This isn't a transgender story, this is a story of abuse. Did you read the article? Did you do any research into this at all? Did you at least read his biography? Because I have. To summarize: David was born a cisgendered man whose doctors botched his circumcision so badly he needed reconstructive surgery. His parents consulted a sexologist they saw on TV (the now disgraced John Money), and he convinced the parents to give David a sex change. Not for David's benefit mind you, but because the sexologist wanted to make a name for himself based on his theories on gender being easily malleable (and he briefly did, until the truth came out). A lot of gross messed up stuff happened, like the sexologist would make David roleplay sex with his twin brother I shit you not. He would make them watch hetero porn with him. And then he would make them get into sexual positions and make them playact sex together. He also took photos (and I think video) of these two children simulating sex.

So to summarize real quick, the pedo-sexologist who committed acts of psychological, medical and sexual abuse on these children, is your "pioneering study" guy. Let me guess, you thought that John Money was a success and that he proved his theory that gender identity is easily manipulated? I've seen this exact anti-trans disinformation twist before, along with thinking David was trans (he wasn't) and pointing out David's "trans suicide". You should be more suspicious of your sources for information. By the 90s we already knew John Moneys work with David was useless. And the disinfo machine loves to leave out a very important fact: Davids brother Brian killed himself two years before David took his own life. I guess the suicide of the depressed cisgendered brother who never transitioned muddies the trans-suicide agenda being pushed.

Whenever I see his story pop up, the terfs (and the unfortunately misinformed) end up erroneously thinking this is a story of a trans kid who killed themself. Disinfo will say this story proves that you can manipulate someone into believing they're a different gender then they know themselves to be. And look! Disinfo swears theres reputable science papers by John Money to back this up! ha.

David was a straight, cisgendered man. His story is not a transgender story. It's many other things; a story of child abuse, medical abuse, psychological abuse and sexual abuse. It's the a story of a cisgendered person experiencing gender dysphoria and not understanding why. To me, what his story really shows us is that a persons personal sense of gender is an innate and pervasive thing; a complex combination of mind and body that persists; no matter how much abuse you throw at it. Because even though David was raised to believe he was a woman; had his role as a woman constantly being reinforced by his entire world, had everyone in his life telling him he was a woman, he still knew he was a man and deeply struggled to understand why he felt that way.

further reading/citations:

the 1997 medical paper & review of Moneys work that, along with Davids testimony, began to shed light on this: http://www.hawaii.edu/PCSS/biblio/articles/1961to1999/1997-sex-reassignment.html

Davids biography: As Nature Made Him: The Boy Who Was Raised As A Girl by John Colapinto

a more detailed and damning article from 2017: https://embryo.asu.edu/pages/david-reimer-and-john-money-gender-reassignment-controversy-johnjoan-case

a very disturbing amount of detail of what happened for those that can handle it: https://www.simplypsychology.org/david-reimer.html

and finally wikipedia for those that hate fancy links: https://en.wikipedia.org/wiki/John_Money#Sex_reassignment_of_David_Reimer