From infancy to adulthood: the development of numerical abilities

Developmental and school-related changes in basic number, counting, and ari thmetic skills from infancy to old age are reviewed. Nearly all of the quan titative competencies that emerge during infancy and the preschool years ap pear to reflect the operation of a biological primary, or inherent, cogniti ve system, and appear to be universal in their expression and development. In contrast, most of the basic quantitative competencies acquired in school and that are of importance in industrial societies do not have a direct in herent foundation. As a result, the development of these secondary quantita tive abilities varies considerably with educational practices and can, and often does, vary from one country or generation to the next. Variability in the development of secondary quantitative abilities greatly complicates th e study of the relation between pathological (e.g., dyscalculia due to stro ke) and age-related processes and these abilities.