Dr. Thomas A. Harris MD (b. 1910 – d. 1995) was a practicing Psychiatrist and the author of the bestselling book I’m OK – You’re OK .  Since the publication of I’m OK – You’re OK in 1969, over 15 million copies have been sold with translations into over 20 languages.

I’m OK – You’re OK is based on the theories of Transactional Analysis developed by Dr. Eric Berne in the bestseller Games People Play in 1964.  Harris wrote that most people live out their lives in the negative “I’m Not OK – You’re OK” state, leading to dysfunctional emotional reactions towards the people around you. Harris defines this and other states and gives sound advice to allow all people to adopt the ideal “I’m OK – You’re OK” mindset. For Harris, being OK with yourself and with others is the way to happiness, personal satisfaction, and good relationships.

Harris’s down-to-earth language and easy to understand writing made the book and instant bestseller. It also made the phrase “I’m OK – You’re OK” an instant part of the American vocabulary.  The book reached number one on the New York Times Best Seller List for non-fiction works in 1972.  With over 20 translations, the theme of I’m OK – You’re OK is recognizable on all six habitable continents.

Photo of Dr. Thomas A. Harris MD, 1968

Harris was born in 1910 in Texas. After receiving his medical degree, he became a psychiatrist and entered the Navy.  After a long Naval career as a psychiatrist, he left in 1954.  He entered into private practice in 1956 and became interested in Transactional Analysis and became an early collaborator with Dr. Eric Berne.  Harris served as the President of the International Transactional Analysis Association. Even with the runaway success of I’m OK – You’re OK, Harris remained in private practice treating patients. He passed away in 1995.

A more comprehensive biography with a rare high resolution photograph is located here.