Strengths and Weaknesses in the Intellectual Profile of Different Subtypes of Specific Learning Disorder: A Study on 1,049 Diagnosed Children

The present study analyzes whether and how the most common diagnoses within the specific learning disorder (SLD) category are characterized by different intellectual profiles. The issue is relevant to the current debate on the unitary versus decomposable nature of the SLD category and may help define specific interventions. Intellectual profiles were obtained using the Wechsler Intelligence Scale for Children–IV (WISC-IV) on 1,049 children diagnosed with SLD using the ICD-10 codes. Four major subsamples were compared: reading disorder, spelling disorder, disorder of arithmetical skills, and mixed disorder of scholastic skills. The four main WISC-IV indexes (verbal comprehension, perceptual reasoning, working memory, and processing speed) were considered. Results showed that all SLD subgroups share similar weaknesses in working memory and processing speed, but they also showed that the subgroups are characterized by partly different intellectual profiles. These specificities should be considered in the definition of SLD.