Book excerpt: Drawing on an extensive survey of real people and over 40 years of research, this revealing volume proposes that a nonmonogamous lifestyle may be healthier for marriages than a monogamous one. Based on an exhaustive survey into the lives of real people, Swinging in America: Love, Sex, and Marriage in the 21st Century concludes that nonmonogamous relationships such as swinging and polyamory offer a new blueprint for combining sex and love—one that may prove more in line with the way people actually live their lives in our society. Swinging in America begins with what we know about swingers and the swinging lifestyle, based on personal narratives and over 40 years of sociological research comparing swinging and non-swinging couples on factors such as personal happiness, marital satisfaction, psychological stability, and personal values. The second half of the book explores the historical rise and contemporary decline of monocentrism—the sexually monogamous marriage as the organizing principle underlying our culture—and the implications of this decline for new nonmonogamous relationships and marriages.