The 'Monster Study' told orphans they had stutters — and some never recovered

In 1939, University of Iowa speech pathology professor Wendell Johnson and graduate student Mary Tudor designed a study to test whether labeling speech patterns could cause or cure stuttering. They selected 22 children from the Iowa Soldiers' Orphans' Home in Davenport, dividing them into four groups. Stuttering children in one group were praised for their speech; normal-speaking children in another group were told they were developing a stutter and were harshly criticized for every speech disfluency. The children had no knowledge of the experiment and gave no consent.

The results were devastating. The normal-speaking children who were criticized developed speech problems — stuttering, hesitation, and withdrawal — that persisted in many cases for decades. One subject later wrote that Tudor 'destroyed my life.' Johnson's hypothesis was supported, but the cost in human terms was severe. Johnson never published the study. Fellow researchers at Iowa called it the 'Monster Study,' and the thesis sat in the university archives for over sixty years, an open secret.

In 2001, investigative journalist Jim Dyer of the San Jose Mercury News discovered the thesis in the university archives and published a series of articles. The story prompted national outrage and a public apology from the University of Iowa. In 2007, seven surviving subjects from the criticized group sued the State of Iowa for lifelong psychological and emotional damages. The state settled for $925,000 — approximately $130,000 per plaintiff — while admitting no wrongdoing.

The Monster Study is now a core case in research ethics education. It demonstrates why vulnerable populations — especially children, especially institutionalized children — require the highest level of ethical protection in research. The University of Iowa's Speech and Hearing Clinic still bears Wendell Johnson's name.