Do women have sex simply to reproduce or display their affection? When Cindy M. Meston, a clinical psychologist at the University of Texas at Austin, and evolutionary psychologist David M. Buss joined forces to investigate the underlying sexual motivations of women, what they found astonished them. Through the voices of real women, Meston and Buss reveal the motivations that guide women's sexual decisions and explain the deep-seated psychology and biology that often unwittingly drive women's desires—sometimes in pursuit of health or pleasure, or sometimes for darker, disturbing reasons that a woman may not fully recognize. Drawing on more than a thousand intensive interviews conducted solely for the book, as well as their pioneering research on physiological response and evolutionary emotions, Why Women Have Sex uncovers an amazingly complex and nuanced portrait of female sexuality. The authors delve into the use of sex as a defensive tactic against a mate's infidelity (protection), as a ploy to boost self-confidence (status), as a barter for gifts or household chores (resource acquisition), or as a cure for a migraine headache (medication). Why Women Have Sex stands as the richest and deepest psychological understanding of female sexuality yet achieved and promises to inform every woman's (and her partner's) awareness of her relationship to sex and her sexuality.