With debates about gender, sex, and sexuality omnipresent in the media, and terms such as “white cis-male” featuring at regular intervals in dinner-time discussions, there is a current market for accessible gender-related literature. Testosterone contributes to this climate from a largely scientific perspective, filling in a void for accessible, purely biological groundings for such debates. Joe Herbert, as an Emeritus Professor of Neuroscience, is well qualified to provide a popular science take on the titular hormone and its involvement in a carefully chosen array of topics, spanning masculinity, femininity, sex and sexuality, aggression, war and making money.

The structure of the book repeats itself throughout, with each chapter dedicated to a different topic: the author first surveys testosterone in the relevant aspect in (non-human) animals (this is interesting from an evolutionary perspective, but also necessary because of the experiments that cannot be conducted on humans), and then discusses experimental results in humans and how these interact with society and higher cognitive functions. A considerable part is also dedicated to what can go wrong: some of the most intriguing discussions concern what happens when testosterone levels are either too low or too high.

The main asset of Testosterone is its accessibility: the potentially very complex and technical biological and chemical phenomena of hormones, cells, synopses and the like are presented with an admirable lucidity that allows for even a reader without an A-level science background to understand. The author also steers clear from making these explanations overly tedious – an omnipresent risk when explaining complex notions to the uninitiated. Fortunately there is just enough background for anyone to grasp the actual discussion. That said, the explanations may well come across as somewhat simplistic, even patronising, to those more well-educated in the sciences; but these parts can be easily skimmed through.

Skimming through, rather than leaving the book on the shelf, is decidedly the right course of action for even the most devout scientists among us, as the more advanced discussions cater for audiences of all backgrounds. Herbert has managed to bring together an intriguing array of topics, all discussed from a scientific perspective – a particularly unique gem is the investigation into testosterone on the trading floors of investment banks. Some of the topics are potentially risky choices for a popular science book, such as rape and homosexuality, but even these are presented without ranting or a programme for social reform. To his credit, Herbert does not veer into domains he should not be venturing into, and Testosterone keeps to its role as a scientific exploration rather than a social pamphlet.

Given the excellent choice of topics, it is somewhat baffling how the discussion at times lingers excessively in the non-human animal world, used mainly as an introduction into the principal discussion. More than once, the biological groundings could be conveyed with fewer animal-related examples, giving more focus on the actual topic. The chapter on testosterone in women, in particular, could have gone into more detail and covered more aspects of the topic under discussion. Another flaw of Testosterone is its excessive endnotes, appearing at a rate of nearly one per page. They disrupt the reading experience, and not much crucial information is missed if they are skipped. As such, a majority of the notes would have perhaps been better incorporated into the main text or just left out.

‘Hormones’ and ‘a gripping read’ rarely feature in the same sentence, but perhaps surprisingly to the science non-aficionados among us, Testosterone achieves precisely this: it whisks the reader through the multifaceted roles of testosterone with clarity and intriguing examples. Testosterone may well occasionally offer more breadth than depth, but on the whole, Herbert has managed to produce a solid didactic experience in some of the biological aspects of sex and gender for those interested in biology as such, and also for those more inclined to wider gender issues alike.