John (Jack) Goodrich Watkins was born on March 17, 1913, in Salem, Idaho. By age 12 he was publishing in the . Watkins obtained his Bachelor's and Master's degrees from the College of Idaho and his Ph.D. from Columbia University. At age 19, while just starting college, Watkins met and married his first wife Evelyn Browne. The two had a son, John Dean. During World War II he enlisted as a private in the Army. When his education became known, he was promoted to Lieutenant and given the position of Chief Psychologist at the Welch Convalescent Military Hospital in Daytona Beach, Florida. Directly following World War II, Watkins' focus became war neuroses (PTSD), and he found hypnosis among other treatments helpful when working with veterans. In 1946 Watkins married his second wife, Doris Wood Tomlinson. Together they had four children: Jonette, Richard, Greg, and Rodney. Watkins was the Chief Psychologist at Portland, Oregon's Veterans Administration Hospital and the Chicago Veterans Hospital. He went on to teach at Auburn University and Washington State University-Pullman, and then at the University of Montana in Missoula from 1964 until his retirement in 1984.

John G. Watkins was a pioneering psychologist in the fields of hypnosis, dissociation, and multiple personalities. He is best known for his work with Helen Huth Watkins on Ego-State Theory, and one of his best-known cases was the Kenneth Bianchi criminal proceedings for the Hillside Strangler case. He was a founding secretary of ISCEH (International Society for Clinical and Experimental Hypnosis) and president of the the Society for Clinical and Experimental Hypnosis, the American Board of Psychological Hypnosis, and the Hypnosis Division of The American Psychological Association. Watkins also served as a clinical editor of the International Journal of Clinical and Experimental Hypnosis. He remained active in his discipline after retirement, publishing papers into his 90s. Following Helen's death, John Watkins married Paula J. Etrick on May 16, 2009. He died in Longmont, Colorado on January 12, 2012.

Helen Verner Huth Watkins was born July 19, 1921, as Helyanthe Maria Wagner, to Anna Maria and Josef Wagner in Augsburg, Bavaria (Augsburg, Germany). Her father died before she was born, and she and her mother lived with her grandfather until they immigrated to the United States when she was 11. After entering the United States, they lived in Pittsburg, Pennsylvania with her aunt and uncle. Wagner was briefly married to Robert Verner but was widowed at age 20 when Verner died in World War II. She later married Richard Huth and had two children: Marvin and Karen. Helen Huth received her Bachelor of Arts from Pennsylvania State University and her Master's from the University of Denver in Public Opinion. After graduating, she moved to Montana and took the position of psychologist at the University of Montana Student Counseling Center. There she met John Watkins, who was director of clinical training at the time. Watkins married Helen Huth in December of 1971.

Helen Huth Watkins worked as a counselor for the University of Montana for 30 years. In addition to collaborative research and publications with John Watkins, she authored over 40 scientific articles. While the Watkins' collaborative works often focused on the Ego-State, Helen Watkins' individual work was mainly focused on improving therapeutic counseling. She became known as the "therapists' therapist" as dozens of mental health professionals, psychiatrists, and psychologists saw her for personal therapy and training. In 2000 she was awarded the "Pierre Janet Award for Clinical Excellence" from an international congress at the University of Munich for her work and dedication to the field of psychology and therapy. Helen Watkins died in Missoula on January 11, 2002.