A Hypothesis of Reading Instruction as a Cause of Dyslexia

Abstract

Dyslexia is a reading disability affecting a large number of people worldwide. People with dyslexia have at least normal levels of intelligence, yet they nevertheless have significant difficulties with reading. Dyslexia is known to have genetic causes; however, some researchers believe that there are also environmental factors at play. Specifically, the way in which a child is taught to read can possibly influence whether or not that child ultimately ends up with dyslexia or other reading difficulties. This paper presents the hypothesis that the way a child is taught to read can be a major factor in the development of dyslexia. There has been speculation about this idea in previous literature, but that speculation has been based only on anecdotes and case studies; empirical research is added in this paper. This hypothesis is based on research showing that certain approaches to teaching reading can induce difficulties with phonetic skills (in other words, difficulty associating written letters with spoken sounds in a language that uses an alphabetic writing system) and fMRI-measurable brain patterns matching those of people with dyslexia. Additionally relevant is that those approaches are widespread in the English-speaking world—most specifically in the United States. Reading difficulties not related to phonetic skills would not be implicated in this hypothesis. The literature justifying this hypothesis is discussed, as well as the challenges to the hypothesis and a way that it can be tested. The importance of proposing this hypothesis is that if flawed reading instruction is indeed one primary cause of dyslexia, then reform in elementary schools is vital.