Monster Study began in 1939 inside the Iowa Soldiers’ and Sailors’ Orphans’ Home in Davenport, Iowa. Graduate student Mary Tudor, working under speech pathologist Wendell Johnson at the University of Iowa, sought to determine whether the way children were labeled could permanently alter how they spoke. Twenty-two orphans, ranging in age from five to sixteen, became unwitting participants in the experiment.
Tudor divided the twenty-two children into carefully structured groups that received contrasting verbal conditioning. Participants previously identified as stutterers were told their speech was normal and would continue improving with practice, while fluent children were informed that their speech showed signs of stuttering and required constant attention. The procedure aimed to measure whether repeated suggestion could create or reduce speech disfluency.
Over a four-month period, Tudor met each participant individually, following scripted sessions that instructed her to reinforce the assigned message through steady repetition. She recorded minute variations in word flow, rhythm, and hesitation but gave little thought to emotional responses. When the project concluded, she compiled the findings in a 1939 master’s thesis and filed it in the University of Iowa library.
For more than six decades, the document remained unexamined. The orphans carried speech anxieties they could not explain, unaware that their fears originated in a controlled study. In 2001, journalist James N. Dyer of the San Jose Mercury News located Tudor’s forgotten thesis and published an investigative feature detailing the experiment. Public reaction was swift. The University of Iowa issued a formal apology, acknowledging that the 1939 stuttering experiment had violated basic ethical principles.
What the 1939 Monster Study at the Iowa orphans’ home revealed about speech and suggestion
The Iowa Soldiers’ and Sailors’ Orphans’ Home in Davenport, Iowa, operated as a state-run institution for children who had lost parents or could not remain in family care. In early 1939, Wendell Johnson and Mary Tudor screened 256 residents to classify speech patterns. After extensive evaluation, they selected 22 children between the ages of five and sixteen for the controlled study.
Tudor divided the 22 participants into four groups: two composed of children who already stuttered and two of fluent speakers. Each group received contrasting verbal instruction. The first stuttering group was told repeatedly that their speech was improving and that they would soon speak as well as anyone. The second group continued to be addressed as stutterers without reassurance. Among the fluent children, one group was informed that their speech displayed signs of stuttering and needed correction, while the control group was praised for clear articulation and told their voices were excellent.
Each session followed a written script to ensure uniform language. Tudor instructed participants labeled as stutterers that pauses, hesitations, or repeated syllables indicated serious speech defects requiring immediate self-correction. Those classified as normal were told that occasional slips were natural and temporary. The orphanage staff were quietly instructed to reinforce these categories during the children’s daily interactions, creating a complete environment of confirmation around each assigned label.
To evaluate progress, Tudor recorded samples of each child’s speech before and after the intervention. Five independent judges, unaware of group assignments, rated fluency on a five-point scale and counted disfluency types including repetitions, prolongations, and interjections. The data aimed to quantify whether suggestion could produce measurable shifts in speech performance. No guardian consent was requested, and participants were never informed of the study’s purpose or its potential risks.
Tudor’s notes show that several children began displaying marked hesitation, lowered confidence, and avoidance of speech by the end of the four-month period. Afterward, she returned to the home three times in an attempt to reverse the changes through praise and reassurance, but later conceded in her thesis that those efforts “were not enough.”
Why Wendell Johnson’s diagnosogenic theory changed stuttering research at the University of Iowa
Wendell Johnson developed his diagnosogenic theory from personal experience with stuttering and a conviction that environment could shape human behavior. He proposed that adult reactions to minor disfluencies transform attention into anxiety and anxiety into persistent interruption. As he wrote, “stuttering begins not in the child’s mouth but in the parent’s ear.”
The theory aligned closely with the behaviorist movement of the 1930s, when psychologists emphasized learning through reinforcement and punishment. Johnson’s research rejected mechanical mouth devices and punitive correction methods then common in speech therapy. His clinic encouraged teachers and parents to maintain calm, praise progress, and eliminate criticism, arguing that kindness could prevent the creation of stuttering altogether.
Mary Tudor worked within this framework as Johnson’s graduate student. The Davenport experiment was designed to confirm whether labeling alone could cause or cure stuttering. If suggestion could provoke disfluency in fluent speakers, then reassurance might restore confidence in existing stutterers. This assumption, narrow but systematic, defined the structure and purpose of the 1939 Monster Study.
Johnson’s ideas quickly shaped clinical practice across the United States. Throughout the 1940s and 1950s, speech therapists adopted his approach of non-interference. Parents were urged not to emphasize mistakes. Teachers were trained to praise clear phrasing rather than interrupt. Clinics across the Midwest modeled their programs on Iowa’s example, and Johnson became a national authority in speech pathology.
By the 1960s, new evidence began to complicate his purely environmental explanation. Neurological studies identified irregularities in timing and auditory feedback among people who stutter. Genetic analyses pointed to familial clustering, suggesting heritable factors. Researchers concluded that stuttering arose from a complex interaction of biology, cognition, and environment rather than from labeling alone.
Even as later science moved beyond it, Johnson’s theory left a lasting imprint. His insistence on empathy reshaped the tone of therapy, replacing punishment with support. Yet the Monster Study revealed the danger of testing compassion through deception. A theory built to protect children from harm had, in practice, subjected them to it, ensuring the 1939 stuttering experiment would remain a defining case in the study of research ethics.
When the Monster Study resurfaced in 2001 and forced the University of Iowa to apologize
For more than 60 years, Mary Tudor’s 1939 thesis remained stored on library shelves at the University of Iowa. It was rarely checked out and contained no preface, warning, or institutional commentary. In 2001, journalist James N. Dyer discovered the bound volume while researching a book on stuttering and quickly realized its significance. His article for the San Jose Mercury News, published on June 11, 2001, revealed that 22 orphans at the Iowa Soldiers’ and Sailors’ Orphans’ Home had been used in a secret stuttering experiment designed to test a psychological theory.
The report attracted national attention. The Washington Post, reprinting an Associated Press dispatch, ran the headline “Taught Them to Stutter” and described how children at a Depression-era orphanage had been “instructed in a lesson they would never forget.” The phrase Monster Study spread across publications and broadcasts, encapsulating the moral outrage surrounding a project that had blurred the line between research and cruelty.
Within days, the University of Iowa released a formal statement describing the experiment as “regrettable” and acknowledging that it violated principles of informed consent. Administrators emphasized that the institution now operated under strict oversight through Institutional Review Boards, which require approval, documented consent, and regular monitoring. Vice President David Skorton declared, “The University of Iowa is deeply sorry,” and stressed that in 1939 there had been “no effective safeguards” for human research participants.
The apology sought to balance accountability with reassurance. Officials framed the study as a historical lapse rather than an institutional intent to harm, noting that modern ethical systems would prevent any repetition. The Chronicle of Higher Education and other outlets reported that Iowa administrators identified the surviving participants by name and expressed regret directly to them.
Media coverage quickly expanded to include the voices of the orphans themselves. Several surviving participants described decades of shame, fear, and hesitation that had followed them through education and employment. One woman recalled that she had avoided speaking publicly her entire adult life. Others said they only understood their speech problems after reading about the experiment. The Monster Study thus moved from archival obscurity to national scrutiny, exposing the human consequences behind academic data.
Scholars and clinicians disagreed on how to interpret responsibility. Some speech pathologists defended Johnson’s theoretical intentions, arguing that he had sought to demonstrate how parental overcorrection might worsen disfluency. Historians and ethicists countered that motives did not erase harm. As one University of Iowa historian observed, “Even if it was accepted locally, that does not mean it was right.” The rediscovery of the Monster Study became not only a news story but a lesson in how forgotten research can redefine an institution’s legacy.
Who the Monster Study survivors were and how they won justice against the State of Iowa
Public scrutiny soon moved from newspapers to the courts. Surviving participants of the Monster Study, along with the estates of those who had died, filed lawsuits against the State of Iowa and the University of Iowa seeking compensation for lasting psychological and physical harm. State attorneys invoked sovereign immunity and argued that the claims were barred by the statute of limitations. The plaintiffs countered that they had only discovered the experiment after the 2001 San Jose Mercury News investigation and could not have acted earlier.
In October 2005, the Iowa Supreme Court issued a 4–3 decision allowing the case to proceed. The majority held that the children, as wards of the state in 1939, had not given consent and could pursue damages once they learned the facts decades later. The decision rejected the state’s procedural defenses and shifted the dispute from legal technicalities to the substance of responsibility.
After extended negotiations, Iowa reached a settlement on August 20, 2007. According to The Chronicle of Higher Education, the state agreed to pay a total of $925,000 to six plaintiffs. Five survivors shared $900,000, while a sixth received $25,000. The settlement included a formal denial of legal liability but represented official acknowledgment that harm had occurred. All remaining lawsuits were dismissed once payments were completed, closing the judicial record without a trial.
Iowa Attorney General Tom Miller described the agreement as “fair and appropriate,” adding that it would “provide closure to experiences from long ago and to memories going back almost seventy years.” University officials echoed this position, emphasizing that the institution had long since implemented rigorous ethical oversight and that the 1939 stuttering experiment violated every standard now governing human-subject research.
Administrators expressed regret but avoided direct admissions of misconduct, portraying the event as a reflection of the era’s norms rather than institutional intent. For the survivors, however, the settlement brought mixed emotions. Many said the compensation could not repair a lifetime of self-doubt or the pain of discovering that their suffering had been deliberate. Mary Korlaske, later known as Mary Nixon, summarized that feeling in a letter to Tudor: “You stolen my life away from me.” Her words, quoted in multiple reports, came to represent the lasting human cost of the Monster Study.
What the Davenport children experienced during and after the University of Iowa stuttering experiment
Interviews with surviving participants revealed how deeply the 1939 stuttering experiment shaped their lives. Survivors described avoiding classrooms, public readings, and any occupation that required frequent speaking. Several never married or withdrew socially, explaining that conversation felt unsafe. Many learned of the experiment only after 2001, when journalists uncovered Tudor’s thesis and linked their lifelong speech anxiety to what had occurred in Davenport.
Tudor’s field notes documented measurable behavioral change. One six-year-old boy began covering his mouth while speaking after being told he showed “symptoms of stuttering.” Others became quiet in group discussions and hesitant to volunteer answers. Children who already stuttered sometimes showed modest improvement when treated with reassurance, yet the gains were inconsistent. Across all groups, the dominant outcome was fear, an internalized expectation of failure that persisted long after the study ended.
Tudor attempted to reverse the effects through three follow-up visits. She praised the children’s speech and labeled it normal, hoping repetition could undo the damage. In her 1939 thesis, she acknowledged that these sessions “were not enough.” By then, memory and habit had hardened. Reclassification could not erase the lesson that authority had defined their voices as defective.
Academic reassessment decades later produced mixed findings. A 2002 reanalysis of Tudor’s original data by Ehud Yairi and Nicoline Ambrose found no statistically significant proof that labeling alone caused stuttering. The sample size was small, and caretaker compliance inconsistent. Yet, the absence of numerical certainty did not diminish the lived harm described by those who endured the sessions.
Survivors consistently linked later speech problems and low confidence to the Monster Study. Three publicly named both Tudor and Johnson as responsible for their suffering. Tudor, interviewed late in life, expressed remorse, stating, “I didn’t like what I was doing. Today I probably would have challenged it. But back then, you did what you were told.” Her words reflected both regret and the limits of academic hierarchy in 1939.
The Monster Study remains most revealing when judged by its outcomes. Children were persuaded that ordinary speech was broken and required constant correction. That message turned self-expression into fear. The 1939 stuttering experiment demonstrates how unchecked authority can transform ideas into harm, and why informed consent and accountability remain the foundation of ethical research.
Why the Monster Study became a turning point in human research ethics and speech pathology
In 1939, formal oversight of human research in the United States did not exist. Institutional Review Boards were decades away, informed consent was not required, and there were no federal regulations for protecting vulnerable participants. Researchers operated under personal judgment and institutional habit. The orphans in Davenport had no advocate when decisions were made on their behalf.
The University of Iowa’s 2001 apology acknowledged that absence of protection. Administrators stated that in 1939 “there were no effective safeguards” and that modern research policy would prevent such work entirely. Under the Common Rule now governing U.S. human-subject research, all studies must undergo independent review, data monitoring, and written consent. Projects involving minors require both parental permission and the child’s assent under Subpart D of the federal regulations.
Ethical reform developed through global reaction to abuses. The Nuremberg Code of 1947 declared voluntary consent “absolutely essential” in human experimentation. Later scandals, including the Tuskegee Syphilis Study, led Congress to pass the National Research Act in 1974, creating the nationwide system of Institutional Review Boards. Those bodies now evaluate risk, participant selection, privacy safeguards, and stopping rules before any human study begins.
By modern standards, the Monster Study would be rejected during preliminary review. Recruiting orphans, using deception, and inducing psychological distress would violate principles of respect, beneficence, and justice. Reviewers would ask whether potential knowledge outweighed harm, whether safer alternatives existed, and whether participants could withdraw freely. Each question would prevent the proposal from proceeding.
Some defenders argue that standards evolve and that judging past work by modern rules is unfair. The historical record contradicts that defense. The children were misled, their guardians were not consulted, and the consequences were never assessed. Ethics is not only a code; it is a continuous act of questioning whose interests are served and whose voices are missing.
The Monster Study now functions as a cornerstone in ethics education. It demonstrates why consent must be informed and voluntary, why vulnerable participants require additional protection, and why good intentions cannot offset harm. Every research-ethics course that cites Davenport turns its painful history into instruction for how science must never again proceed in silence.
Curious about how imagination looked on the other end of history? Read our feature Wild and Brilliant Inventions That Capture the Bold Creativity of People in the 1800s, which explores the strange, fearless energy that once drove inventors to experiment with flying machines, mechanical limbs, and underwater contraptions long before ethics committees or safety manuals existed.