WINNER OF THE 2017 ROYAL SOCIETY INSIGHT INVESTMENT SCIENCE BOOK PRIZE

What the judges said: 'Every man and woman should read this book on gender bias ... an important, yet wickedly witty, book.' 

'Fine's entertaining and thoughtful book is a valuable addition to the discussion about gender.' Ian Critchley, Sunday Times

 'In addition to being hopeful, Fine is also angry. We should all be angry. Testosterone Rex is a debunking rumble that ought to inspire a roar.' Guardian

'A densely packed, spirited book, with an unusual combination of academic rigour and readability ... The expression "essential reading for everyone" is usually untrue as well as a cliché, but if there were a book deserving of that description this might just be it.' Antonia Macaro, Financial Times

Testosterone Rex is the powerful myth that squashes hopes of sex equality by telling us that men and women have evolved different natures. Fixed in an ancestral past that rewarded competitive men and caring women, these differences are supposedly re-created in each generation by sex hormones and male and female brains.

Testosterone, so we're told, is the very essence of masculinity, and biological sex is a fundamental force in our development. Not so, says psychologist Cordelia Fine, who shows, with wit and panache, that sex doesn't create male and female natures. Instead, sex, hormones, culture and evolution work together in ways that make past and present gender dynamics only a serving suggestion for the future - not a recipe.

Testosterone Rex brings together evolutionary science, psychology, neuroscience and social history to move beyond old 'nature versus nurture' debates, and to explain why it's time to unmake the tyrannical myth of Testosterone Rex.

For fans of Fine - whose Delusions of Gender 'could have far-reaching consequences as significant as The Female Eunuch' (Viv Groskop, Guardian) - and thousands of new readers, this is an upbeat, timely and important contribution to the debate about gender in society.

"Testosterone Rex is a debunking rumble that ought to inspire a roar." - The Guardian

"It is extraordinary how so much is attributed to such a minute quantity of hormone. Cordelia Fine combines formidable intellect, forensic analysis and devastating wit to expose those myths of sex, gender and human behaviour that might just reflect testosterone-fuelled, wishful thinking. This engaging, accessible and hopefully influential book doesn't disappoint, and makes crucial reading for those with an interest, from any perspective, in human behaviour." - School of BioSciences, University of Melbourne

"The delusion that there are distinct and unique male and female natures, put in place by an unholy alliance of genes, hormones and neurones, remains alive and well. Cordelia Fine dismantles this myth with style, wit and scientific precision. This combination of scientific responsibility and general accessibility is desperately needed if we are to escape the serious social damage caused by such widely disseminated pseudoscience." - Director, Egenis, Centre for the Study of Life Sciences, University of Exeter

"Goodbye beliefs in sex differences disguised as evolutionary facts. Welcome the dragon slayer: Cordelia Fine wittily but meticulously lays bare the irrational arguments that we use to justify gender politics." - Emeritus Professor of Cognitive Development, University College, London

"This is an important, well researched book that presents biological, psychological and social science research to explain why men and women are far less different than many would have you believe. If that sounds dry, it ain't. Fine lives up to her name - she is an extremely talented writer." - Evolutionary Ecology, Australian National University

"Cordelia Fine has done it again: she debunked the idea of a female brain in Delusions of Gender and has now slain Testosterone Rex. This is obligatory reading for anyone interested in gender equality at work or home - your views on sex differences will never be the same." - journalist and author of Seven Myths About Women at Work

"This book is brilliant" - New Scientist

"Ms Fine's is a provocative and often fascinating book." - The Economist

"Endless books claim that the brains of men and women are wired differently. They set out to convince us that women are somehow biologically suited to getting the creases out of clothes while men peruse maps. This brilliant book proves our attitudes to men and women are cultural, not natural. Fine makes the neuroscience clear and provides a wealth of ammunition to debunk the myth that sex inequality is just something we're born with." - The Observer