Origins and Developments
This chapter discusses the research and theory pertaining to demographic differences in cognitive abilities, and general intelligence. Developmental delays and deficiencies in general intelligence and specific cognitive abilities are not independent of other disorders. Individual and group intelligence tests may also contain items designed to measure perceptual speed and accuracy, memory, inductive and deductive reasoning, and other cognitive skills. Children with extremely high or low intelligence, in addition to those with special learning, physical, or emotional disabilities, are designated as exceptional or special in schools. Tests of intelligence designed to measure scholastic aptitude contain verbal, mathematical and other school-type tasks. General intelligence, as measured by Binet-type tests, is more highly correlated with success in school-type tasks than with performance in out-of-school situations. Memory, which is basic to cognitive performance, in general, has been studied extensively by experimental and physiological psychologists. In addition, some people who do not possess unusually high abilities in other areas have exceptional memories.