"With all the talk about testosterone in sex, sports and politics, we need a good explanation of the science and its implications, and this one is outstanding.' STEVEN PINKER, bestselling author of The Blank Slate 'There are whole books written about the idea that behavioural sex differences are a societal construct and how a male hormone we know influences animal behaviour somehow doesn't influence us. Hooven's book is a riposte to that silliness - and also a defence of a hormone that isn't just about aggression.' TOM WHIPPLE, THE TIMES, BEST SCIENCE BOOKS OF 2021 'Fascinating, vital, unputdownable.' JULIE BINDEL 'The definitive book on testosterone . . . A brave and significant book . . . simply fascinating and filled with extraordinary facts.' EVENING STANDARD 'Testosterone does what all superb popular science must do: it entertains as it educates.' THE WALL STREET JOURNAL Through riveting personal stories and the latest research, Harvard evolutionary biologist Carole Hooven shows how testosterone drives the behaviour of the sexes apart and how understanding the science behind this hormone is empowering for all.