The book “Sex/Gender” by Anne Fausto-Sterling offers a fresh viewpoint on how biological variations might develop over time in reaction to social and environmental events. This book expresses the scientific and cultural bases of gender, including the social construction of gender, neurobiology, and biochemistry. A broad audience is drawn in by Fausto-Sterling’s approachable writing style, which also absorbs the social, political, moral, and ethical facets of this complicated topic.