Testosterone Rex
by Cordelia Fine
Summary
Testosterone Rex is Fine's name for the beast she means to hunt: the familiar story in which testosterone, acting on ancient evolutionary imperatives, builds fundamentally different male and female natures, risk taking and promiscuous on one side, cautious and coy on the other, and thereby explains everything from trading floors to toy aisles. The book is a systematic, very funny demolition.
She works through the story's load bearing walls in turn. The evolutionary premise, that promiscuity profits males and modesty females, turns out shakier than its fame, from Bateman's flawed fruit fly experiments onward, and the animal kingdom declines to cooperate, competitive females and choosy males abounding. The developmental premise, that hormones fix brains into male and female types, dissolves into the data: sex differences in brains and behaviour are mosaics, distributions overlapping far more than they separate, with almost no individual a pure type. The risk taking premise fails its own tests, risk appetite proving domain specific and culture sensitive, the gender gap shrinking wherever the measures stop assuming it. And testosterone itself, the rex, emerges as less king than courtier, a hormone that follows social circumstance, victory, status, even holding a baby, as much as it leads.
The conclusion is carefully bounded: not that biology is nothing, but that the familiar story is bad biology, and that societies keep citing it to naturalise arrangements they chose.
Around two hundred and sixty pages, footnoted and fast.
Best for readers who want the sex difference debate conducted with data and jokes, by its sharpest sceptic.
Historical Context & Significance
Testosterone Rex won the Royal Society prize in 2017, the judges praising a forensic look at gender stereotypes, and the choice was, in the politest way available, a provocation: the Society handing its book prize to a philosopher psychologist best known for prosecuting popular neuroscience's gender claims, in a decade when the debate was radioactive.
Cordelia Fine, a Melbourne professor with Oxford and Cambridge credentials, had built the case across a trilogy: A Mind of Its Own, on self deception, then Delusions of Gender, which coined neurosexism and made her name, with this book completing the argument at the hormonal and evolutionary levels.
The response mapped the territory: applause from much of psychology and biology's mosaic brain camp, pushback from researchers who found the treatment of real average differences too quick, and a long half life in syllabuses on both sides. The rex, as brand and target, has never recovered its old swagger in respectable print, which was the point.