John Money(https://en.wikipedia.org/wiki/John_Money) was a psychologist who coined the term gender as we know it now. Money is most famous for his work with the Reimer twins (https://en.wikipedia.org/wiki/David_Reimer).

David Reimer and his twin brother were both born as a male with intact penises. Both of the boys were circumcised which sadly mutilated David's penis beyond repair. The doctors decided to cut off David's penis and give him a vagina. Throughout adolescence, David was given female hormones. He was raised as a girl and was never told that he was actually born male. As David started to enter puberty, he was sure of his male sex. When other males would try to be romantic with him, it felt very wrong to him. He began to "transition" to male as a teenager. https://embryo.asu.edu/pages/david-reimer-and-john-money-gender-reassignment-controversy-johnjoan-case

This case was used to justify thousands of sex reassignment surgeries as it was regarded as a success by John Money. David spoke out against sex reassignment surgeries for children. How this case isn't the nail in the coffin for the trans cult is beyond me.

As part of Money's "treatment" the pedo had the boys act out sexual activities in front of him which he filmed. Both of the brothers committed suicide in their adult years. Perhaps his most notable contribution was coining the term "gender." Gender is ultimately meaningless, though it has now firmly planted itself in the social lexicon. Money's theory was that gender could be learned.

As we know, you can learn to cook, sew, and knit, but does that change your sex? Are you any less or more of a woman if you do or don't know how to do these things? Are men lesser if they do?

It's important when talking about the T to make the firm distinction between sex and gender, as the two are often used interchangeably now.