What is the main conflict in The Red Queen: Sex and the Evolution of Human Nature by Matt Ridley?

The Red Queen is an investigation into how sexual selection and the arms race for reproductive advantage between males and females is responsible for many cultural and biological facts that are characteristic of humans. In the book, the author explains both the biology and how that biological facts translate into culture differences. Fashion, beauty, monogamy, intelligence, and many other aspects of human psychology are explained through biological evolution by way of sexual selection.