It was dubbed the "Monster Study" as some of Johnson's peers were horrified that he would experiment on orphan children to confirm a hypothesis. The experiment was kept hidden for fear Johnson's reputation would be tarnished in the wake of human experiments conducted by the Nazis during World War II. Because the results of the study were never published in any peer-reviewed journal, Tudor's thesis is the only official record of the details of the experiment.The University of Iowa publicly apologized for the Monster Study in 2001. However, Patricia Zebrowski, University of Iowa assistant professor of speech pathology and audiology notes that the data that resulted from the experiment is the "largest collection of scientific information" on the phenomenon of stuttering and that Johnson's work was the first to discuss the importance of the stutterer's thoughts, attitudes, beliefs, and feelings and continues to influence views on stuttering greatly.
On the first visit, Tudor tested each child's I.Q. and identified whether they were left-handed or right-handed. A popular theory at the time held that stuttering was caused by a cerebral imbalance. If, for example, a person was born left-handed but was using their right hand, their nerve impulses would misfire, affecting their speech. Johnson did not believe the theory, but still suggested Tudor test each child's handedness. She had them draw on chalkboards and squeeze the bulb of the dynamometer. Most were right-handed, but left-handed children were present in all the groups. There was no correlation between handedness and speech in the subjects. During this period, they assigned numbers to the children, such as "Case No 15 Experimental Group IIA..."The experimental period lasted from January until late May 1939, and the actual intervention consisted of Tudor driving to Davenport from Iowa City every few weeks and talking with each child for about 45 minutes. She followed an agreed-upon script. In her dissertation, she reported that she talked to the stuttering youngsters who were going to be told that they did not stutter. She said to them, in part, "You'll outgrow [the stuttering], and you will be able to speak even much better than you are speaking now... Pay no attention to what others say about your speaking ability for undoubtedly they do not realize that this is only a phase."To the non-stuttering youngsters in IIA, who were to be branded stutterers, she said: "The staff has come to the conclusion that you have a great deal of trouble with your speech… You have many of the symptoms of a child who is beginning to stutter. You must try to stop yourself immediately. Use your will power… Do anything to keep from stuttering… Don't ever speak unless you can do it right. You see how [the name of a child in the institution who stuttered severely] stutters, don't you? Well, he undoubtedly started this very same way."The children in IIA responded immediately. After her second session with 5-year-old Norma Jean Pugh, Tudor wrote, "It was very difficult to get her to speak, although she spoke very freely the month before." Another in the group, 9-year-old Betty Romp, "practically refuses to talk," a researcher wrote in his final evaluation. "Held hand or arm over eyes most of the time." Hazel Potter, 15, the oldest in her group, became "much more conscious of herself, and she talked less," Tudor noted. Potter also began to interject and to snap her fingers in frustration. She was asked why she said 'a' so much. "Because I'm afraid I can't say the next word." "Why did you snap your fingers?" "Because I was afraid I was going to say 'a.'"
All the children's schoolwork fell off. One of the boys began refusing to recite in class. The other, eleven-year-old Clarence Fifer, started anxiously correcting himself. "He stopped and told me he was going to have trouble on words before he said them," Tudor reported. She asked him how he knew. He said that the sound "wouldn't come out. Feels like it's stuck in there."
The sixth orphan, Mary Korlaske, a 12-year-old, grew withdrawn and fractious. During their sessions, Tudor asked whether her best friend knew about her 'stuttering,' Korlaske muttered, "No." "Why not?" Korlaske shuffled her feet. "I hardly ever talk to her." Two years later, she ran away from the orphanage and eventually ended up at the rougher Industrial School for Girls — simultaneously escaping her human experimentation.
Mary Tudor herself wasn't untouched. Three times after her experiment had officially ended she returned to the orphanage to voluntarily provide follow-up care. She told the IIA children that they didn't stutter after all. The impact, however well-meaning, was questionable. She wrote to Johnson about the orphans in a slightly defensive letter dated April 22, 1940, "I believe that in time they … will recover, but we certainly made a definite impression on them."
The article revealed that several of the orphans had long-lasting psychological effects stemming from the experiment. The state tried unsuccessfully to have the lawsuit dismissed but in September 2005, Iowa's Supreme Court justices agreed with a lower court in rejecting the state's claim of immunity and petition for dismissal.
Many of the orphans testified that they were harmed by the "Monster Study" but outside of Mary Tudor, who testified in a deposition on November 19, 2002, there were no eyewitnesses. The advanced age of the three surviving former orphans on the plaintiff's side helped expedite a settlement with the state.
"For the plaintiffs, we hope and believe it will help provide closure relating to experiences from long ago and to memories going back almost 70 years. For all parties, it ends long-running, difficult and costly litigation that only would have run up more expenses and delayed resolution to plaintiffs who are in their seventies and eighties." (DM Register)
Despite the settlement, the debate remains contentious over what harm, if any, the Monster Study caused the orphan children. Nicholas Johnson, the son of the late Wendell Johnson, has vehemently defended his father. He and some speech pathologists have argued that Wendell Johnson did not intend to harm the orphan children and that none of the orphans were diagnosed as "stutterers" at the end of the experiment. Other speech pathologists have condemned the experiment and said that the orphans' speech and behavior was adversely affected by the negative conditioning they received. Letters between Mary Tudor and Wendell Johnson that were written shortly after the experiment ended showed that the children's speech had deteriorated significantly. Mary Tudor returned to the orphanage three times to try to reverse the negative effects caused by the experiment but lamented the fact that she was unable to provide enough positive therapy to reverse the deleterious effects. (Ethics and Orphans. San Jose Mercury News).
Today, the American Speech-Language-Hearing Association prohibits experimentation on children when there exists a significant chance of causing lasting harmful consequences.