With two new chapters by the author. If we all want love, why is there so much conflict in our most cherished relationships? To answer this question, says noted psychologist David Buss, we must look into our evolutionary past. Based on the most massive study of human mating ever undertaken, encompassing more than ten thousand people of all ages from thirty-seven cultures worldwide, The Evolution of Desire is the first book to present a unified theory of human mating behavior. Now in a revised and updated edition, Buss's classic presents the latest research in the field, including startling new discoveries about the evolutionary advantages of infidelity, orgasm, and physical attractiveness.