In 1939, a young psychology student from Iowa named Mary Tudor began the research project, “Monster Study.” Tudor's supervisor, Wendell Johnson, had a theory that the reason why some people stutter is that at some point in their childhood, someone had made them too self-aware of their own speech, causing them distress and impairing their fluency.
If Johnson was right, stuttering would be an acquired trait. To test his hypothesis, Tudor ran an experiment with a group of children from a nearby orphanage.
The “Monster Study” did not find any evidence to support Wendell’s theory, but it caused long-term trauma to many of their participants, particularly the children who could speak clearly but were told their speech was not normal to try to provoke stuttering.
