Dyslexia is a specific learning disability that is neurological in origin. It is characterized by difficulties with accurate and / or fluent word recognition and by poor spelling and decoding abilities. These difficulties typically result from a deficit in the phonological component of language that is often unexpected in relation to other cognitive abilities and the provision of effective classroom instruction.

Secondary consequences may include problems in reading comprehension and reduced reading experience that can impede growth of vocabulary and background knowledge.”

Adopted by the IDA Board of Directors, Nov. 12, 2002. Many state education codes, including New Jersey, Ohio and Utah, have adopted this definition. Learn more about how consensus was reached on this definition: Definition Consensus Project.

Dyslexia and intelligence are not connected. The results from a study done at Yale Center for Dyslexia & Creativity indicate that in typical readers, IQ and reading track together and are dynamically linked over time. They are like “kissing cousins” according to Dr. Sally Shaywitz as evidenced by the they are “intertwined”. In contrast, IQ and reading diverge in people with dyslexia. Thus, an intelligent student with dyslexia could have very low reading score. 1

1. Ferrer, E., Shaywitz, B.A., Holahan, J.M., Marchione, K., and Shaywitz, S.E. Uncoupling of Reading and IQ Over Time: Empirical Evidence for a Definition of Dyslexia. Psychological Science, 21(1) 93–101, 2010.]