Intelligence and dyslexia: Implications for diagnosis and intervention

In this paper we critically examine theoretical issues and practical conseq uences of including IQ in the definition of dyslexia. According to the disc repancy criterion individuals are classified as dyslexic if their reading s kills are below what would be expected from their IQ scores. However, we ar gue that intelligence is a fuzzy concept and that there is no clear causal relationship between intelligence level and word decoding skills. Also, hig h and low IQ poor readers show the same reading performance patterns, indic ating that both groups might benefit from the same remedial activities. Evi dence for the critical role of phonological skills in dyslexia is presented and a more recent definition of dyslexia is discussed in relation to these findings. Finally, two alternative, more outcome-based classifications of poor readers are suggested and some critical consequences for individual in terventions are outlined.