In the stories of the Brothers Grimm, children are cautioned not to stray into the forest, lest they be gobbled up by wolves or transformed by witches. As Nature Made Him: The Boy Who Was Raised as a Girl begins in a very different part of the woods, in 1967, as a monster transforms a little boy. The “monster” is scientific authority; its lair is social attitudes; its weapon is shame.

Bruce Reimer was born to working class parents in mid-1960s Winnipeg. When he lost his penis in a botched circumcision, he came to the attention of the charismatic, celebrated sex researcher Dr. John Money. Money was a key proselytizer of a new orthodoxy regarding sexual identity. Science had thus far failed to prove much in the way of biological roots to male and female behaviour, so attention shifted to nurture, not nature. By the time Money arrived at Johns Hopkins University it was believed that environment alone dictated gender. But the new hypothesis needed a test case, a young enough child – a boy or girl with indeterminate genitals – who could be successfully raised as the opposite sex. With the one-year-old Bruce Reimer, Money hit the experimental jackpot: not only did the Canadian child have a male twin (ideal for any control study), but the parents were uneducated and deferential. The social and moral climate was perfect. Who knew how to refuse – or question – the man in the white coat?

Bruce was renamed Brenda, and under Money’s long-distance tutelage Brenda was made pretty in pink. But what followed was a descent into hell: lonely Brenda grew up in agony, a messed-up changeling who didn’t fit in with either sex and so lost the sanction of both. When the teenage Brenda finally learned the truth, she refused her dresses and hormone pills, denying an inhuman doctrine (her “conversion” was by now entrenched in the literature of transgenderism) and refusing to be imprisoned by gossip, prejudice, and fear.

Renamed David, Brenda is now much happier, and emerges in this excellent book as a supremely old soul, a veteran of the sex wars in ways the rest of us cannot imagine. But the darkest question remains, and runs throughout the book like an elusive monster: why did society deem a boy without a penis not a boy at all?