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The Monster Study on Stuttering, by Wendell Johnson

The Monster Study on Stuttering, by Wendell Johnson

July 12, 2024

The Monster Study is a research that was conducted in the United States in the 1930s and that aimed to find out the effects of different therapies in children with language and communication disorders.

This study has generated debates and controversies that have marked an important part of the research in psychology, specifically with respect to its ethical dilemmas. Next we explain what the Monster Study is, how was its approach and what are the reasons why it is considered a controversial investigation .

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What is the Monster Study?

The Monster Study is an investigation on language fluency disorder (stuttering) , which was conducted by the American psychologist Wendell Johnson in 1939. It was done under the supervision of Johnson, but directly conducted by one of his graduate students, Maria Tudor.


The research was conducted at the University of Iowa and involved twenty-two orphaned children from the Veterans Orphanage also in Iowa. The main objective of the study was to analyze whether stuttering could be induced and whether it could be reduced with a therapy based on positive reinforcement.

In contrast to the winning brain theories arises in its time, Wendell believed that stuttering is a learned behavior , and as such, could be unlearned and also induced.

According to the psychologist, stuttering occurs when the person who listens to someone who speaks fluently, evaluates this as something undesirable; issue that is perceived by the speaker and causes tension and concern.


The consequence of this tension and concern is that the speaker worsens the fluidity of his speech; which generates more anguish and again causes stuttering. In other words, for Wedell stuttering is a consequence of the effort to avoid stuttering, which is caused by the pressure exerted by the person listening.

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Study design

The Monster Study began by selecting the 22 children who participated. Of that 22 selected children, there were 10 who had a stuttering previously detected by their teachers and caregivers.

Afterwards, Tudor and his research team personally evaluated the children's speech. They thus generated a scale from 1 to 5 where the 1 referred to the lowest fluidity; and 5 referred to the highest fluency. Thus, they divided the group of children: 5 of them were assigned to an experimental group and the other 5 to a control group.


The other 12 children who participated did not have any language or communication disorder and they were chosen at random also within the orphanage . Six of these 12 children were also assigned to a control group and the other 6 to an experimental group. They were between 5 and 15 years old.

None of the children knew they were participating in an investigation; They believed that they were really receiving a therapy that would last 4 months, from January to May 1939 (the time the study lasted).

María Tudor had prepared a therapy script for each group. Half of the children would say some positive phrases, trying to stop the children from paying attention to the negative comments that others make about their speech; and the other half I would say those same negative comments and would emphasize every error of his speech .

Main results

The 22 children were divided according to whether they had a language disorder or not, in a control group and an experimental group. Children in the experimental group received language therapy based on positive reinforcement. This included, for example, praising the fluidity of his speech and words. This applied as much to children who had stuttering as to those who did not have or had very little.

To the other half of children, those in the control group, Tudor gave them a therapy based on the opposite: negative reinforcers. For example, he extolled every imperfection of language, belittled speech, emphasized that they were "stuttering children" ; and if the children did not have any disorder, he told them that they were not speaking well and that they were showing the first symptoms of stuttering.

The only conclusive result was that the participants of this last group quickly presented symptoms of anxiety, especially because of the shame that caused them to speak, which is why they began to correct each speech obsessively, and even avoid communication. To himself his schoolwork declined and his behavior changed towards withdrawal.

Why is it known as a "monster" study?

This studio it is known as a "monster" because of the ethical dilemmas it has generated . The group of children who received the therapy based on negative reinforcements, presented psychological effects also negative in the long term, in addition to those who already had language disorders, kept them throughout their lives.

Once the study was over, Tudor voluntarily returned to the orphanage to offer help to those who had developed anxiety and to those who had worsened the fluency of their speech. Even tested with therapy based on positive reinforcers .

Likewise, Johnson apologized a year later saying that the children would surely recover over time, although it was clear that their study had left a mark on them.

Johnson's colleagues and colleagues dubbed this investigation the "Monster Study," describing as inadmissible the use of orphan children to test a hypothesis. Currently, and after several similar cases, the ethical norms of research in psychology have been reformulated in an important way.

After having remained hidden, this investigation came to light and caused the University of Iowa to publicly apologize in the year 2001 . This same university faced a demand of thousands of dollars from several of the children (now adults) who had been affected in the long term by the investigation.

Bibliographic references:

  • Goldfarb, R. (2006). Ethics A Case Study from Fluency. Plural Publishing: USA
  • Polti, I. (2013). Ethics in research: analysis from a current perspective on paradigmatic cases of research in psychology. Paper presented at the V International Congress of Research and Professional Practice in Psychology. Faculty of Psychology, University of Buenos Aires, Buenos Aires. [Online] Available at //www.aacademica.org/000-054/51
  • Rodríguez, P. (2002). Stuttering from the perspective of stutterers. Central University of Venezuela. Retrieved May 12, 2018. Available at //www.pedrorodriguez.info/documentos/Tesis_Doctoral.pdf.

The Monster Study: A Stuttering Experiment (July 2024).


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