Now, in a groundbreaking book that will transform our understanding of our species, evolutionary psychologist Geoffrey Miller argues that our brains evolved not because of natural selection but because of sexual selection. Like the peacock's magnificent multicolored tail, the human brain is an extravagance whose sole advantage, he claims, is to attract a mate and pass on genes. Our ancestors were attracted not just to pretty faces and strong bodies but to partners with quick wits, intelligence, and generous spirits -- sexually attractive traits that speak to our fertility, health, and the quality of our genes. The richness and subtlety of human language, art, music, creativity, and morality are all the result of sexual choices made over countless generations. In a book based on the latest discoveries in evolutionary biology, the author shows that romantic success and the heartbreak of sexual rejection have been the major forces driving the human mind's evolution.