Dyslexia is a learning disorder characterized by difficulties with accurate and fluent word recognition, poor spelling, and decoding abilities that are unexpected in relation to a person’s intelligence and educational opportunities. The recognition of this condition in the United States was a gradual evolution spanning decades of medical observation and educational research. This history involves moving from vague imported labels to a specific neurological hypothesis and finally to practical instructional methods.
Early 20th Century: Identifying “Word Blindness” in America
The earliest recognition of a reading disability in the United States was heavily influenced by observations from European medical professionals. The concept of “word blindness,” originating in the late 19th century, described individuals who struggled to read despite having normal vision and intelligence. This imported term served as the initial framework for American physicians and educators attempting to categorize students who were failing to acquire literacy skills.
In 1905, Cleveland ophthalmologist Dr. W.E. Bruner published one of the first American reports detailing childhood reading difficulties. His work confirmed that some children possessed a puzzling discrepancy: high cognitive ability paired with a profound inability to read. These observations were often made in isolation, and the medical community lacked a unified, uniquely American theory to explain the underlying cause. The diagnostic label was borrowed, and the mechanism remained a mystery.
Defining Dyslexia: Samuel T. Orton and Strephosymbolia
The definition of the reading disability in America shifted dramatically due to the seminal work of American neurologist Samuel T. Orton, beginning in the 1920s. Orton, a neuropsychiatrist, applied his knowledge of adult brain injuries to the study of children who struggled with language processing despite seemingly intact neurological function. He observed that many of the children displayed a tendency to reverse letters and transpose the order of letters within words.
Orton rejected the European term “word blindness,” arguing it was inaccurate since the children could see words perfectly well but struggled to process them. In 1925, he introduced his specific term, “strephosymbolia,” which literally means “twisted symbols.” This concept was the first clear, uniquely American neurological hypothesis for the condition, suggesting the difficulty arose from a lack of complete cerebral dominance.
He theorized that the reading difficulties were caused by the non-dominant hemisphere of the brain mirroring images and symbols, which interfered with the processing of the correct image in the dominant hemisphere. Orton’s hypothesis suggested that the two hemispheres were competing for control, preventing the clear establishment of left-to-right progression necessary for reading. This focus on a neurological basis—a difference in brain organization rather than a simple visual defect—provided the foundation for future American research and definition of the disorder.
Transitioning from Medical Discovery to Educational Recognition
Following Orton’s foundational research, the focus shifted toward translating his findings into practical educational strategies. Orton collaborated closely with educator and psychologist Anna Gillingham, who helped transform his theoretical principles into a structured teaching methodology. This collaboration, beginning in the 1930s, resulted in the development of the systematic and multisensory teaching approach known as the Orton-Gillingham method.
This instructional method emphasized integrating auditory, visual, and kinesthetic learning channels to help students process language. Gillingham and her colleague Bessie Stillman compiled the instructional materials in The Gillingham Manual: Remedial Training for Children with Specific Disability in Reading, Spelling, and Penmanship, published in the mid-1930s. The approach was sequential, explicit, and focused on phonics, targeting the underlying language processing weaknesses Orton had identified.
The movement gained momentum with the formation of advocacy and professional groups dedicated to promoting Orton’s work. The Orton Society, established after his death, later evolved into the International Dyslexia Association. These organizations were instrumental in bridging the gap between medical discovery and educational practice, advocating for the recognition of dyslexia within US school systems. This transition established the link between a specific neurological profile and the necessity for a specialized, structured educational intervention.