Intelligence: In Pursuit of Rational Thought and Effective Action 143
Digit Symbol:mental flexibility and ability to employ arbitrary symbols.
Picture Completion:ability to detect the missing parts of an organized whole
(i.e., a Gestalt).
Block Design:ability to relate a printed pattern to a physical construction.
Picture Arrangement:ability to comprehend the “before and after” aspect of
time. Also useful in evaluating the subject’s level of social intelligence.
Object Assembly:ability to place parts in a correct relationship to a whole.
Under optimal conditions, a trained psychologist administers the Wechsler
Adult Intelligence Scale to a given to a subject on an individual basis. The results
of the test, when properly scored and evaluated, provide a clear picture of the
individual’s level of cognitive functioning at both a general level and at the level
of specific mental abilities.
(a) The Wechsler Adult Intelligence Scale consists of a set of how many subtests?
(b) What subtest in the Verbal Scale is designed to assess the subject’s ability to understand
questions and grasp concepts?
(c) What subtest in the Verbal Scale is designed to assess the subject’s grasp of the meaning
of words?
(d) What subtest in the Performance Scale is designed to assess the subject’s mental flexibil-
ity and ability to employ arbitrary symbols?
(e) What subtest in the Performance Scale is designed to assess the subject’s ability to relate
a printed pattern to a physical construction?
Answers: (a) Eleven; (b) Comprehension; (c) Vocabulary; (d) Digit Symbol; (e) Block Design.
The Concept of an Intelligence Quotient: Following
the Bell-Shaped Curve
As already noted, the concept of mental age (MA) is of limited value because it is
unstable. As one’s chronological age (CA)increases, so does one’s mental age.
Consequently, a German psychologist named William Stern suggested that a ratio
based on the comparison of mental age with chronological age would tend to be
relatively stable. Stern proposed the following formula:
IQ =
M
CA
A
× 100
IQstands for intelligence quotient.The IQ is a quotient because it is the
result of a division process.
