The Monster Study: Authority, Identity & The Stories We Inherit About Ourselves

The Monster Study: The Unethical Psychology Experiment That Made Children Question Their Own Voices

In 1939, a young graduate student named Mary Tudor arrived at the Iowa Soldiers' Orphans' Home carrying out an experiment on something most of us rarely think about until it goes wrong: speech.

The study was overseen by University of Iowa psychologist Wendell Johnson, one of the most influential researchers in the field of stuttering at the time. Johnson had developed a controversial theory: He believed stuttering might not begin entirely as a physical or neurological problem, but could instead be made worse—or perhaps even created—by the way adults reacted to a child's speech. So, Tudor set out to test it.

Twenty-two children at the orphanage were divided into groups. Some already stuttered, while others spoke normally. But six specific children, who had no diagnosed speech disorder, were given a very different message: They were told they were beginning to stutter.

Tudor began listening closely to their speech, pointing out hesitations and repetitions they would have had little reason to notice. Ordinary imperfections became warning signs, and the children were cautioned to think carefully before speaking and to avoid talking unless they could do so correctly.

The experiment did not produce the result its researchers were looking for. The normally fluent children didn't develop the kind of persistent developmental stuttering Johnson hoped the study might explain, and something else happened instead.

Tudor's notes described children becoming increasingly self-conscious about speaking. Some grew quieter, and others became reluctant to participate in class (or noticeably hesitant when they did speak). One child reportedly began covering her mouth with her hand. So, while the experiment may not have created stuttering, it certainly appears to have changed the way several children experienced their own voices, and that makes the Monster Study interesting for reasons that extend far beyond the history of speech pathology. These children had not suddenly lost the ability to speak and instead what changed was the meaning attached to the way they spoke.

Adults with authority had begun watching them differently, and small mistakes were identified as evidence of a problem. Behaviors that had once passed unnoticed became something to monitor, correct, and fear. So, eventually, and unfortunately, the children began monitoring themselves.

The study remained largely obscure for decades, and the most shocking element of this story is that the children involved were never told at the time that the criticism they received had been part of an experiment. Some wouldn't learn the truth until many years later.

Today, the Monster Study is remembered primarily as an example of research ethics gone badly wrong, and deservedly so. Children living in an institutional setting were subjected to psychological manipulation without meaningful consent, all in service of testing a theory. But the part I find harder to shake is what happened to them psychologically.

There is a particular kind of power in being told who you are by someone you believe has the authority to know.

A child told repeatedly that she is bad at math may eventually stop raising her hand. Someone who is constantly described as awkward may begin scrutinizing every social interaction for evidence that it's true. A teenager repeatedly told that they're too emotional, too difficult, too sensitive, or too much can eventually start organizing their behavior around avoiding those labels. As one of those teenagers myself, I can at the very least attest to that this seemingly benign experience can have a long-lasting impact.

Because at some point, the distinction between observation and identity can get blurry.

That's what makes the Monster Study more than an unsettling footnote in the history of psychology. It raises a question that is much more personal than whether researchers in 1939 behaved ethically.

How much of who we become is shaped by what other people repeatedly tell us we are?

In this episode of Pretty Evil, we look at Wendell Johnson's theory, Mary Tudor's role in carrying out the experiment, the children who became its subjects, and what the study accidentally revealed about authority, self-perception, and the strange psychological process by which someone else's judgment can eventually start sounding like our own voice.