In this episode, Xavier Bonilla has a dialogue with Carole Hooven about the hormone Testosterone and its impact on men and within society. They discuss her new book and reasons for writing the book. They talk about sex hormones and the sexual reproductive system as well as the impact of sexual selection on both. They provide definitions of male and female within a biological framework including discussions on the genetics, hormones, and gametes. They talk about the impact of culture and environment on gender expression and biological sex. The talk about how hormones are distributed throughout the body and the importance of secondary sex characteristics. They talk about the Mullerian and Wolffian ducts and also give different examples of how hormones interact with the environment. They discuss the complexities of discussing biology and environment in current society and many other topics.  Carole Hooven is a Lecturer and Co-Director of the undergraduate program in the Department of Human Evolutionary Biology at Harvard University. She has a Bachelors in Psychology from Antioch College and a PhD from Harvard University. Her main research areas are sex differences, testosterone, and hormones interaction with behaviors. She is the author of T: The Story of Testosterone, the Hormone that Dominates and Divides Us which you can purchase here. You can find her at her website. Twitter: @hoovlet