Margery Runyan, PhD, identical twin and psychotherapist, describes her research into the dreams of female identical twins, female twins who lost their twins, and female singles. The study was designed to explore the cognitive schema of twins through dreams to give direction to psychotherapists treating twins. The findings support the idea that female identical twins have more complex dreams than female singles due to thinner personality boundaries. The dreams of twinless twins exhibit a greater evolution of the self and paranormal abilities. Twins in general have unique conceptual schema including a powerful co-twin and more events experienced, stored, and dreamed than do singles. The book contains a thorough review of both dream research and twin research. This book is one of the few available on the subject of adult twinship.