Examined the assumption that Spearman's law acts unsystematically and approximately uniformly for various subtests of cognitive ability in an IQ test battery when high- and low-ability IQ groups are selected. Data from national standardization samples for Wechsler adult and child IQ tests affirm regularities in Spearman's "Law of Diminishing…

Three experiments investigated the possibility that adult age differences on block design tasks originate because of reduced efficiency with increased age in the cognitive processes associated with block manipulation. Older adults were substantially slower and less efficient than younger adults in performing tasks with minimized design…

Results from a representative sample of 123 adults in the United Kingdom tested with the Wechsler Adult Intelligence Scale-Revised and a test of word identification time are in line with previous findings that speed of information processing is significantly related to performance IQ but not to verbal IQ. (SLD)

Various experiments demonstrated that the difficulty level of several performance-type intelligence test tasks is determined directly by stimulus and task variables that vary the information to be processed. The implications of these findings for intelligence and the problems of an experimental approach to the measurement of intelligence are…

This study investigated the relationship between measures of speed of cognitive information processing and intelligence test scores. Cognitive processing measures were significantly related to IQ scores. Reaction time tests measure cognitive operations basic to intelligence, and individual differences in intelligence are partly due to variability…