Intelligence Tests

Type of psychology: Intelligence and intelligence testing
Fields of study: Ability tests; intelligence assessment
Individual intelligence tests are used by psychologists to evaluate a person’s current
cognitive ability and prior knowledge. The intelligence testing movement has a
long history, including the development of numerous group and individual tests to
measure one aspect of a person’s overall intelligence, which frequently changes over
time.
Key concepts
• age norm
• cognition
• intelligence
• intelligence quotient (IQ)
• mentally gifted
• mentally handicapped
• percentile
• performance tests
• sensorimotor tests
• verbal tests
Although means for measuring mental ability date as far back as 2000 b.c.e.,
when the ancient Chinese administered oral tests to determine a candidate’s
fitness for carrying out the tasks of civil administration, the modern
intelligence test has its origins in the nineteenth century, when JeanÉtienne-
Dominique Esquirol drew a clear distinction between mentally
deranged people (“lunatics”) and mentally retarded people (“idiots”). Esquirol
believed that it was necessary to devise a means of gauging “normal”
intelligence so that deviations from an agreed-upon norm could be ascertained,
and he pointed out that intellectual ability exists on a continuum extending
from idiocy to genius. His work coincided with studies in Europe
and the United States that were designed to develop a concept of “intelligence”
and to fashion a means of testing this capacity. Work done by Sir
Francis Galton in the United Kingdom on hereditary genius, by James
McKeen Cattell in the United States on individual differences in behavior,
and by Hermann Ebbinghaus in Germany on tests of memory, computation,
and sentence completion culminated in the 1905 Binet-Simon scale,
created by Alfred Binet and Théodore Simon. It was the first practical index
of intelligence measurement as a function of individual differences. This
test was based on the idea that simple sensory functions, which had formed
the core of earlier tests, are not true indicators of intelligence and that
higher mental processes had to be included. 458