The Monster Study
The Monster Study was an experiment intended to test the effects of stigma on childhood stuttering, but it mostly resulted in a whole lot of trauma. In 1939, 22 children from a nearby orphanage, roughly half of whom had a stutter, were brought to a team of psychologists at the University of Iowa headed by Dr. Wendell Johnson to see if labeling a child a "stutterer" versus a "normal speaker" made any difference in their speech development, though perhaps they should have been studying why so many kids at this orphanage had a stutter. Two groups, one of stutterers and one of non-stutterers, were told their speech was fine, instructed to simply practice to overcome any difficulties, and praised for their efforts. Two other, similar groups, however, were chastised for their speech and told not to speak at all unless they were absolutely sure they could articulate properly.
If this was a contest between the carrot or the stick, the carrot won by a long shot. The first two groups' speech improved or at least didn't get worse, but even those in the second groups who previously had no stutter developed problematic speech patterns or simply stopped talking altogether. Some began showing signs of physical distress, such as covering their eyes, and their issues sometimes lasted years beyond the study's conclusion. Eventually, Johnson realized how unethical it was to subject orphaned children to a psychological experiment they didn't even understand, let alone consent to, especially as some of their problems worsened. Moreover, the end of the study coincided with the discovery of horrific pseudoscientific experiments conducted by the Axis powers against prisoners during World War II, so disapproval of nonconsensual studies was at the forefront of the discourse among American scholars.
For all his efforts, Johnson eventually decided not to publish his results, but grad student Mary Tudor used the experiment as her doctoral thesis. When her work was published, she noted that she believed the damage done to the children was significant, though she tried to reverse some of the complications with follow-up care over the following years. Several decades later, the release of the book Ethics: A Case Study From Fluency, which highlighted the study's flaws, brought it once again to public attention. Some speech pathologists did find its ultimate conclusions to be useful, at least insofar as what not to do, but seven of the subjects sued the state of Iowa over the study's lasting effects, and in 2007, they were awarded $1.2 million.