Why do some marriages grow stronger in the face of conflict or stress while others dissolve? In this book, two pioneering researchers present a groundbreaking theory of how mutually responsive behaviors emerge—or fail to emerge—in relationships. Illustrating their findings through the vivid stories of four diverse couples, the authors explore how conscious considerations interact with unconscious impulses to foster trust and commitment. Compelling topics include why marriages have such different personalities and what makes partners truly compatible. Also discussed are implications of the model for helping couples sustain satisfying relationships and improve troubled ones.