Thomas A. Harris is a practicing psychiatrist in Sacramento, California. Born in Texas, he received his B.S. degree in 1938 from the University of Arkansas Medical School and his M.D. in 1940 from Temple University Medical School. In 1942 he began training in psychiatry at St Elizabeth's Hospital in Washington, after which he served as a psychiatrist in the Navy. In 1947 he was appointed Chief of the Psychiatric Branch of the Bureau of Medicine and Surgery in the Navy Department. After retirement from the Navy as Commander, he taught at the University of Arkansas School of Medicine and then became Director of the Department of Institutions for the State of Washington. In 1956 he entered private practice in Sacramento. He is founder and President of the Institute for Transactional Analysis there, and a Director of the International Transactional Analysis Association.

It is important that this book be read from front to back. Were later chapters read before the first chapters, which define the method and vocabulary of Transactional Analysis, the reader not only would miss the full significance of the later chapters but would assuredly make erroneous conclusions.

Chapters 2 and 3 are particularly essential to the understanding of all that follows. For readers who have an irresistible back-to-front reading urge, I wish to emphasize that five words which appear throughout the book have specific meanings different from their usual meanings. They are 'Parent', 'Adult', 'Child', 'OK', and 'games'.