ABSTRACT
A review of recent theories of intelligence and research strongly supports the clinical utility of measuring processing speed (PS) in assessments of intelligence. However, the recent enthusiasm about processing speed as a significant component of intelligence is not an innovative idea in psychology. On the contrary, the use of processing speed as a major factor of intelligence and individual abilities lies at the very core of the birth of psychology as a quantitative science. During the late 1800s and early 1900s Wilhelm Wundt, Sir Francis Galton, James McKeen Cattell and other prominent psychologists strongly asserted that measures of sensory processes (e.g., processing speed) were at the heart of individuals' intellectual abilities. The field followed suit and the zeitgeist of science during the late nineteenth century and early twentieth century included the belief that anthropometric testing was the best way to measure an individual's ability, resulting in the meteoric rise of processing speed research in intelligence.
