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A review by jasonfurman
T: The Story of Testosterone, the Hormone That Dominates and Divides Us by Carole Hooven
5.0
“T: The Story of Testosterone, the Hormone that Divides and Dominates Us” is a superb piece of science writing about the role that testosterone, or T, plays in the development of sex differences and their expression throughout life. Carole Hooven consistently acknowledges and highlights the importance of culture and conscious choices as shaping the way in which T is expressed but is scathing about those who deny a role for T at all. In telling this story Hooven draws mostly on endocrinology (a subject I have never really read about before) but also some more familiar ground in human evolutionary biology and other disciplines as well. She also includes some fascinating history of science from the 19th century discovery that T operated through the vascular system by transplanting testes into the wrong place in young male chickens through many more recent large-scale experiments.
Just reading about how animals have two systems that interact internally to shape development, behavior, and more—the neural system which sends targeted electrical signals and the hormonal system which sends broad communications that can only be received and interpreted by some cells—was very basic biology but still fascinating to me because it was explored with such detail and nuance in this one specific case.
Human males have three major surges of T: one around 20 weeks gestational, one a few months after birth, and one starting around age 12 and lasting for the rest of life. Hooven explains in detail how these surges play a role in the differentiation of primary sex characteristics (the first one) and secondary sex characteristics (the third one, which brings about puberty). She also acknowledges that scientists do not understand that second surge in babies, one of a handful of places throughout the book where she acknowledges and highlights what scientists do not (yet?) understand—which is also part of the never-ending excitement of science because it is a process of discovery not a full truth.
Hooven then has chapters that focus on issues like the role of sexual selection, different performance in sports, vastly different levels of violence, also differences in willingness to risk one’s life for a stranger (a trait heavily skewed towards males), and more. She also discusses the role of T in people transitioning, a very well done chapter that largely tells a set of stories through extended quotes from interviews with a number of people that have transitioned.
Hooven draws on animal studies to illustrate the continuity with humans but also the variety of evolutionary strategies. For example, part of a chapter is devoted to the extraordinary set of studies of red deer in the Isle of Rum off Scotland and the way in which some males maintain harems, fighting off the solitary males who are mateless. She then explains that red deer differ from human babies in that they can fend for themselves almost from birth and so require almost no parental input while paternal input—not just fathering lots of children—is a key input to evolutionary success in humans.
I had mixed feelings about how much of the T was devoted to arguing against a recent set of popular and in some cases scientific writings denying that T matters in humans, instead arguing that humans are a blank slate and that gender differences are entirely socially constructed. I sympathized with how frustrating the reach of these writings given the mountain of evidence against them: animal studies, human studies, examples of humans who had their T cut off (eunuchs and castrati), humans with different types of genes (e.g., XY’s that cannot process T), humans who have transitioned, and other evidence. You can sense Hooven’s frustration about some of the pseudo-science that gets amplified in the press, even on basic factual questions like one person arguing that T levels are not hugely different in men and women when in fact even the highest T women are below the lowest T men. But I did not always like it as a foil.
Hooven, however, is interesting in speculating about why there is this tendency to deny nature--arguing that for some it has become a proxy in the fight for feminism and equality. She is scathing about this view, arguing (correctly in my view—although she does not actually develop and prove the case) that if we downplay or ignore biology we will miss opportunities to improve women’s safety and equality. She also argues that the difference-deniers are making the mistake of implicitly accepting that what is “natural” is good and that instead it is better to argue that people and cultures can change and reshape the way people behave—while acknowledging there are natural differences and these differences themselves are often grounded in one particular chemical and the role it plays throughout our lives, T.
Overall, I learned a lot from this book and found the writing very engaging—highly recommended.
Just reading about how animals have two systems that interact internally to shape development, behavior, and more—the neural system which sends targeted electrical signals and the hormonal system which sends broad communications that can only be received and interpreted by some cells—was very basic biology but still fascinating to me because it was explored with such detail and nuance in this one specific case.
Human males have three major surges of T: one around 20 weeks gestational, one a few months after birth, and one starting around age 12 and lasting for the rest of life. Hooven explains in detail how these surges play a role in the differentiation of primary sex characteristics (the first one) and secondary sex characteristics (the third one, which brings about puberty). She also acknowledges that scientists do not understand that second surge in babies, one of a handful of places throughout the book where she acknowledges and highlights what scientists do not (yet?) understand—which is also part of the never-ending excitement of science because it is a process of discovery not a full truth.
Hooven then has chapters that focus on issues like the role of sexual selection, different performance in sports, vastly different levels of violence, also differences in willingness to risk one’s life for a stranger (a trait heavily skewed towards males), and more. She also discusses the role of T in people transitioning, a very well done chapter that largely tells a set of stories through extended quotes from interviews with a number of people that have transitioned.
Hooven draws on animal studies to illustrate the continuity with humans but also the variety of evolutionary strategies. For example, part of a chapter is devoted to the extraordinary set of studies of red deer in the Isle of Rum off Scotland and the way in which some males maintain harems, fighting off the solitary males who are mateless. She then explains that red deer differ from human babies in that they can fend for themselves almost from birth and so require almost no parental input while paternal input—not just fathering lots of children—is a key input to evolutionary success in humans.
I had mixed feelings about how much of the T was devoted to arguing against a recent set of popular and in some cases scientific writings denying that T matters in humans, instead arguing that humans are a blank slate and that gender differences are entirely socially constructed. I sympathized with how frustrating the reach of these writings given the mountain of evidence against them: animal studies, human studies, examples of humans who had their T cut off (eunuchs and castrati), humans with different types of genes (e.g., XY’s that cannot process T), humans who have transitioned, and other evidence. You can sense Hooven’s frustration about some of the pseudo-science that gets amplified in the press, even on basic factual questions like one person arguing that T levels are not hugely different in men and women when in fact even the highest T women are below the lowest T men. But I did not always like it as a foil.
Hooven, however, is interesting in speculating about why there is this tendency to deny nature--arguing that for some it has become a proxy in the fight for feminism and equality. She is scathing about this view, arguing (correctly in my view—although she does not actually develop and prove the case) that if we downplay or ignore biology we will miss opportunities to improve women’s safety and equality. She also argues that the difference-deniers are making the mistake of implicitly accepting that what is “natural” is good and that instead it is better to argue that people and cultures can change and reshape the way people behave—while acknowledging there are natural differences and these differences themselves are often grounded in one particular chemical and the role it plays throughout our lives, T.
Overall, I learned a lot from this book and found the writing very engaging—highly recommended.