By Emma Florio, Archives & Research Specialist

Kroger as a medical student, ca. 1930. From the 1930 Northwestern Syllabus.

William Saul Kroger was born in Chicago on April 14, 1906, to Russian Jewish immigrant parents. A family story told that he had been stillborn and needed to be revived by the obstetrician, Joseph B. De Lee, himself a Northwestern medical school alumnus and professor, considered the father of modern obstetrics. Kroger’s mother would remind him that an obstetrician had saved his life and insisted that he become a doctor like De Lee. Kroger’s medical career was also influenced by another incident in his childhood. When he was 13, his father hired a hypnotist to generate publicity for his fur store, marking Kroger’s first encounter with hypnotism, although it would take time for him to realize its potential as a medical tool.

Kroger received a Bachelor of Medicine degree from Northwestern University Medical School (NUMS, predecessor of Feinberg School of Medicine) in 1926. During this time, he received his first academic training in hypnosis in the school’s psychology department. After graduating he joined a club that studied psychoanalysis—the form of talk therapy pioneered by Sigmund Freud 30 years earlier—which eventually became the Chicago Psychoanalytic Institute. Kroger continued studying psychotherapy in medical school, but specialized in obstetrics and gynecology, as his mother had always insisted. He earned his MD from NUMS in 1930 and completed a residency in obstetrics, gynecology, and endocrinology at Chicago’s Lying-in Hospital with Joseph De Lee, the obstetrician who had saved his life as a newborn and inadvertently shaped his path in life.

Early in his career, Kroger combined his interests in psychology and obstetrics and gynecology by working in psychosomatic gynecology, focusing on how mental health can influence gynecological conditions. By the 1940s, he had incorporated his interest in hypnosis into his practice, becoming an early advocate for the use of hypnosis in childbirth. The process involved several meetings with the pregnant woman in the weeks or months before delivery, assuring her while under hypnosis that she would not feel any pain or discomfort, and finally cuing her in the delivery room to relax and feel no pain. This could reduce the use of anesthesia (completely in about 25% of cases, according to Kroger) and allowed the woman to remain conscious while giving birth—a very different experience than the typical medicalized childbirth of the mid-20th century, when the woman was heavily sedated. Throughout his career, Kroger stressed that medical hypnosis was very different from the stage hypnosis that people were familiar with, and that patients were never unconscious or in a trance. Instead, he likened the hypnotic state to meditation, a state of increased concentration and relaxation where patients were more susceptible to suggestion. He also emphasized that it was the patient, not the doctor, who truly did the hypnotizing through their faith in the process.

Kroger, ca. 1943. From Clinical and Experimental Hypnosis, revised 2nd edition, 2008.

Kroger pioneered the use of clinical hypnosis in a number of fields over the next 30 years, including obstetrics and gynecology, surgery, sex therapy, and the treatment of addiction and eating disorders. Early on, he was the only doctor in the Chicago area incorporating hypnosis into his practice and championed its use in the face of derision from his medical colleagues. He was associate professor of obstetrics and gynecology at the Chicago Medical School (now part of Rosalind Franklin University) and cofounded the American Society of Clinical Hypnosis, for which he gave lectures and seminars around the world, helping to legitimize the field. Kroger published a number of books, as well, including Clinical and Experimental Hypnosis, the definitive textbook on the subject for decades. He acted as spokesman for the efficacy of medical hypnosis throughout the 1940s and ‘50s, appearing in national newspapers several times and even Time magazine.

After moving to Los Angeles in 1959, Kroger began using hypnosis to aid law enforcement, including the FBI. He again made national news after helping the FBI to apprehend a man who kidnapped a bus driver and 26 children in Chowchilla, California, in 1976—under hypnosis, the driver was able to recall all but one digit of the kidnapper’s license plate, helping the FBI to find and convict him. Proximity to Hollywood brought Kroger celebrity clients as well, including, by his estimate, thousands of performers who he treated for stage fright and the “network nerves” of appearing on talk shows. His prominence in the field also led to an appearance on the television show In Search Of..., hosted by Leonard Nimoy, which explored mysterious phenomena.¹

William Kroger died in Los Angeles on December 4, 1995, at age 89, and was buried in Hollywood’s Forest Lawn cemetery. His legacy lives on in the field of clinical hypnosis, which he helped to pioneer and legitimize over his 60-year career.

1.   Kroger’s appearance can be viewed on Youtube (starting at 3:32, the Chowchilla kidnapping is covered at 17:55).

De Felice, Eugene A. “In Memoriam: Dr. William S. Kroger (1906-1995).” International Journal of Clinical and Experimental Hypnosis 44, no. 4 (October 1996): 287-289.

Yapko, Michael D. “The Early Days: Remembering William S. Kroger, M.D.” American Journal of Clinical Hypnosis 51, no. 1 (July 2008): 37-40.