A disturbing study that was conducted on children has been dubbed 'The Monster Study' due to its unethical nature.
The study was created in 1939 by Wendell Johnson at the University of Iowa. Johnson wanted to understand whether the speech impediment of stuttering could be made worse in children if they were labelled as 'stutterers'.
This came from Johnson's own personal experience. When he was a child, his teacher had mentioned to his parents that he was starting to stutter.
Although he had spoken fine until this point, he began worrying about the problem and soon he was stuttering.
Advert
He claimed later that stuttering 'begins not in the child's mouth but in the parent's ear'.
What happened in the study?
The study was conducted on 22 orphan children who were split into control and experimental groups.
One of Johnson's graduates, Mary Tudor, was running the experiment. She gave positive speech therapy to half of the children, whose speech was praised.
Meanwhile, the other half of the group were labelled as 'stutterers' and lectured over their impediment.
The children had no idea they were taking part in a study.
The students labelled as stutterers were told: ''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 shocking results
Out of the six children who did not have a stutter at the beginning of the study, five began stuttering after the treatment they had endured.
Meanwhile, out of the five children who already had a stutter, three became worse.
In the control group, only one child who had no speech issues before the study reported greater problems once it had finished.
Once they had realised the consequences of the study, the team tried to rectify the damage, but it's reported that the impact on the children was permanent.
What happened next?
It's reported that the study was kept secret until 60 years later, when the truth was revealed in the San Jose Mercury News.
Even the children had no idea they had been involved in the experiment.
According to reports, teachers at the orphanage were also misled about the study - which was never published.
In 2001, 36 years after Johnson died, the University of Iowa formally apologised, calling the experiment regrettable and indefensible.
''Those who had heard about it nicknamed it the 'Monster Study'," Franklin Silverman, a professor of speech pathology at Marquette University and a former student of Johnson's told The New York Times.
''It reminded people of the Nazi experiments on human subjects. The other professors at the time told him that it would ruin his reputation to publish the data.
"It was chilling and disturbing, especially to think that Wendell Johnson, of all people, had sanctioned it. He knew the pain of being told that you stutter.''
Lucy Devine