Unexpected reading precocity in a normal preschooler: implications for hyperlexia.

This is a case study of a left-handed, preschool boy of superior intelligence who read very early and at a level well beyond what his IQ would predict. He is developmentally normal with no signs of autism or related disorders. His reading age was 9.3 at age 2-11 and 11.2 at 4-2; these levels are considerably beyond what would be predicted by his IQ or language age. He was able to read nonwords and both regular and irregular words equally well, indicating his mechanisms of lexical access in reading are similar to those of normal readers. Unlike classical hyperlexics, his reading comprehension for both single words and sentences was well above age level. When his precocious reading first appeared, he was also advanced in reading-related linguistic skills, such as phoneme awareness, auditory verbal short-term memory, and word retrieval, but not in visuospatial skills. These results imply that neither pathological language and/or social development, nor pathological variation in the normal mechanisms of lexical access in reading are necessary causes for reading precocity in early childhood. A model for integrating subtypes of precocious readers with subtypes of normal and dyslexic readers is proposed.