In Testosterone Rex: Myths of Sex, Science and Society, Cordelia Fine looks into the past, present and future research regarding sex differences and testosterone. Fine does not state that there are no sex differences among women and men, and does not state that testosterone does not play a role when looking at biological differences, but the overall message based on research is that these differences are often minute and in many ways do not display the stark differences that are culturally entrenched and part of popular belief.

Fine therefore starts with past research. Studies of the past have depicted sex differences as inherent and significant, stating that men are more promiscuous than women, that male reproductive success is of greater importance and that females are more picky in their determination of mates than males who are more likely to mate with many different females to ensure greater success in developing offspring. What Fine concludes is that these assumptions are not reliant upon sex to the extent that has been proposed in the past. Fine explains that both males and females (in numerous species) vary to the extent in which these traits are present and adopted. Fine also discusses the notion that females are inclined to prefer monogamy, which Fine states research often debunks, and both males and females are more likely to prefer monogamy over short-term relationships with several different individuals. In humans, sex is also typically more intricate and is more often than not for non-reproductive purposes. Fine points out that men and women are inclined to have sex when the possibility of reproduction is low, and that the act of sex in males is also more complicated due to lack of a penis bone. 

In part two, where Fine looks into present research, Fine starts with the notion that sex characteristics are more intricate than XX and XY and there are approximately half a dozen sexes (the terminology used is typically intersex). We are inclined to believe that sex differences are very important in regards to human behavior, but sex differences do little to account for brain differences, and sex is more complicated and unpredictable than most humans are inclined to believe, and Fine again points out that the majority of sex differences are very small. As an example, Fine discusses the notion of risk taking (in which research has a tendency to suggest that men are more likely to take risks, which translates into believes about occupational preferences and abilities). Fine points out that risk taking is not a one-dimensional personality trait and that most humans, males and females are mild risk takers. Instead, societal and social expectations in regards to risk-taking play a significant role, and the same goes for financial risk taking. Fine also discusses the notion of testosterone and concludes that we over-emphasize the role of testosterone and that the role of testosterone in sex differences in much more intricate and interwoven than research tends to suggest.

In regards to research on the future, Fine discusses a hot topic of today, which is sex-segmented toy marketing. In regards to children’s toys we are often inclined to buy different toys (in different colors) for boys and girls, stating that toy and color preferences are somehow inherently determined based on sex. In regards to infants, there are no significant differences in terms of preferences (research has focused on infant’s preferences for faces and mobiles), and such preferences do not show significant differences in children slightly older. What seems to be important is learned expectations in regards to such preferences where children learn the “rules” at a very young age (boys should not wear pink, dolls are for girls). Fine concludes that there are various reasons as to why people want (or do not want) greater equality between the sexes, but ends the book by stating that we need to look elsewhere than simply stating that testosterone is the main culprit as “…evolving science is showing that one time-honored option is no longer available to us. It’s time to stop blaming Testosterone Rex, because that king is dead” (p. 195).

Fine has written a funny and timely book discussing the past, present and future research in regards to sex differences, that is sure to be enjoyed by many. Fine is able to turn what can be, difficult to read research into accessible and interesting material, and one does not have to be an expert in biology, genetics and evolution to enjoy the book.

© 2017 Hennie Weiss

Hennie Weiss has a Master’s Degree in Sociology from California State University, Sacramento. Her academic interests include women’s studies, gender, sexuality and feminism