For decades, the study remained an obscure, shameful footnote in academic circles. When it came to light publicly in the early 2000s, it sparked outrage, lawsuits, and a profound re-examination of research ethics. This is the story of how a well-intentioned scientific inquiry crossed an indelible line. To understand the study, you must understand Wendell Johnson. As a child, Johnson himself was a severe stutterer. This personal struggle drove his academic career; he became one of the most influential speech pathologists of the 20th century at the University of Iowa.
Mary Tudor concluded her thesis with a disturbing observation: The experiment had succeeded in creating "a condition in the child which seems to be the beginning of a real stuttering problem."
"I just wanted to hide," said one subject, Mary Nixon. "I was afraid to say anything because I thought it would be wrong."
The study was complete. But then—nothing happened. The results were never formally published. Wendell Johnson moved on to a long, distinguished career, authoring textbooks and becoming a beloved figure in speech pathology. Mary Tudor became a teacher. The orphanage's records were sealed. For over 60 years, the "Davenport Experiment" remained a secret, buried in the University of Iowa's archives.
Children in the control groups who were praised showed no negative effects. One child who already stuttered but received positive feedback actually improved.