In 2024, my niece Caroline received a Ph.D. in gravitational-wave physics. Her research interests include “the impact of model inaccuracies on biases in parameters recovered from gravitational wave data” and “Petrov type, principal null directions, and Killing tensors of slowly rotating black holes in quadratic gravity.” I watched a little of her dissertation defense, on Zoom, and was lost as soon as she’d finished introducing herself. She and her husband now live in Italy, where she has a postdoctoral appointment.

Caroline’s academic achievements seem especially impressive if you know that until third grade she could barely read: to her, words on a page looked like a pulsing mass. She attended a private school in Connecticut, and there was a set time every day when students selected books to read on their own. “I can’t remember how long that lasted, but it felt endless,” she told me. She hid her disability by turning pages when her classmates did, and by volunteering to draw illustrations during group story-writing projects. One day, she told her grandmother that she could sound out individual letters but when she got to “the end of a row” she couldn’t remember what had come before. A psychologist eventually identified her condition as dyslexia.

Fluent readers sometimes think of dyslexia as a tendency to put letters in the wrong order or facing the wrong direction, but it’s more complicated than that. People with dyslexia have varying degrees of difficulty not only with reading and writing but also with pronouncing new words, recalling known words, recognizing rhymes, dividing words into syllables, and comprehending written material. Dyslexia frequently has a genetic component, and it exists even in speakers of languages that don’t have alphabets, such as Chinese. It often occurs in combination with additional speech and language issues, and with anxiety, depression, attention disorders, and other so-called comorbidities, although dyslexia itself can have such profound psychological and emotional impacts that some of these conditions might be characterized more accurately as side effects.

Estimates of dyslexia’s incidence in the general population vary, from as high as twenty per cent—a figure cited by, among others, Sally Shaywitz, a co-founder of the Yale Center for Dyslexia & Creativity—to as low as zero, as suggested by Richard Allington, a retired professor of education at the University of Tennessee, Knoxville, who in 2019 told participants at a literacy conference that legislators who supported remediation for students with reading disabilities should be shot. Nadine Gaab, a professor at the Harvard Graduate School of Education, told me that the best current estimates fall between five and ten per cent.

There are reasons for the inconsistency. The condition varies in type, severity, and presentation of symptoms, and early literacy skills have historically been hard to measure. Many children with dyslexia (and their parents) never learn they have it. Because a common strategy for avoiding the embarrassment of reading aloud is to act in a way that results in being sent to the principal’s office, dyslexic students are often treated primarily as discipline problems. At every grade level, they are more likely to be suspended, expelled, or placed in juvenile detention, especially if their families are economically disadvantaged. According to a 2011 study of four thousand high-school students by Donald J. Hernandez, then a sociology professor at Hunter College, more than sixty per cent of those who failed to graduate had been found to have reading deficits as early as third grade. More often than not, schools don’t intervene effectively, sometimes out of ignorance, sometimes as a result of misguided pedagogy, sometimes for fear of incurring instructional or legal costs.

The personal and societal consequences can be catastrophic, since even to work at many minimum-wage jobs you need to be able to read. The tragedy is compounded by the fact that proven methods for teaching dyslexic students—which enabled Caroline to become an avid reader by middle school—have been known for decades. What’s more, the main principles that inform those methods have been shown to underlie successful reading instruction for all students, whether they have dyslexia or not. (An administrator at a school for students with reading disabilities told me, “What works for our students actually works for everyone. It’s a matter of dosage.”) Many American schools don’t use scientifically supported instructional methods, though, and, partly because they don’t, dyslexia can be hard to distinguish from what one elementary-school principal described to me as “dystaughtia.” If reading were taught better, almost all students would benefit, and students with neurological differences would be easier to identify and treat before their difficulties with reading derailed their lives. “There’s a window of opportunity to intervene,” Mark Seidenberg, a cognitive neuroscientist, told me. “You don’t want to let that go.”

Shaywitz, in her book “Overcoming Dyslexia,” cites an account, published by a German doctor in 1676, of “an old man of 65 years” who lost the ability to read after suffering a stroke. “He did not know a single letter nor could he distinguish one from another,” the doctor wrote. This was perhaps the first published description of what’s known today as acquired dyslexia, caused by damage to the brain. Two centuries later, a doctor in England wrote a paper about a case of what he called “congenital word blindness.” It involved a fourteen-year-old boy who was unable to read despite years of instruction by teachers and tutors. He could recognize “and,” “the,” “of,” and a few other one-syllable words, and he knew the letters of the alphabet, but when the doctor dictated vocabulary to him he misspelled nearly everything, writing “sening” for “shilling” and “scojock” for “subject.” His disability stood out, the doctor wrote, because his schoolmaster had said that he would be “the smartest lad in the school if the instruction were entirely oral.” Read the full story here.