Clinical Psychology

7years,3months.Reliabilities for the composite
scores exceeded .89. The WPPSI was standardized
atthesametimeasapopularmeasureofachievement
(the Wechsler Individual Achievement Test Third
Edition–WIAT-III), allowing for close comparisons
between intellectual ability and achievement and
strong validity support.

The Clinical Use of Intelligence Tests

In the preceding sections, we have described several
of the more commonly used intelligence tests. It is
time to take a closer look at how such tests are used
in the clinical setting.

The Estimation of General Intellectual Level.
The most obvious use of an intelligence test is as a
means for arriving at an estimate of the patient’s
general intellectual level. Frequently, the goal is
the determination of how much general intelligence
(g) a given person possesses. Often, the question is
stated a bit differently—for example, What is the
patient’s intellectual potential? Posing the question
in this way suggests that perhaps the person is not
functioning as well as his or her potential would
indicate. The potential can form a baseline against
which to measure current achievements, thus pro-
viding information about the patient’s current level
of functioning. This can be especially useful when
attempting to determine whether a child’s academic
difficulties are due to cognitive or mental health dif-
ficulties, or whether a child’s academic achievement

is substantially lower than their cognitive ability (i.e.,

in extreme cases, this is referred to as a Learning

Disability). Intellectual ability test results, when avail-

able, also can be used to help determine how well an

individual may be able to recover cognitive abilities

following a head trauma, illness, or surgery that com-

promises intellectual performance.

Many pitfalls and fallacies are associated with

the pursuit of these goals, however. The following

is an example.

This example is but the tip of the iceberg. It

does suggest, however, that obtaining an IQ is not

the end of a clinician’s task—it is only the begin-

ning. The IQ score must be interpreted. Only

through knowledge of the patient’s learning history

and by observations made during the testing situa-

tion can that score be placed in an appropriate

interpretive context and adequately evaluated.

Prediction of Academic Success. As mentioned

previously, there are data that demonstrate a rela-

tionship between intelligence test scores and school

success (Hunt, 2011; Neisser et al., 1996; Ones et

al., 2005). To the extent that intelligence should

logically reflect the capacity to do well in school,

we are justified in expecting intelligence tests to

predict school success. Not everyone would equate

intelligence with scholastic aptitude, but the fact

remains that a major function of intelligence tests

is to predict school performance. One must

remember, however, that intelligence and academic

success are not conceptually identical.

The Case of Harold

Harold was being routinely evaluated prior to transfer to

a special class for advanced junior high school students.

Rather surprisingly, his Full Scale WISC-IV IQ turned out

to be 107. This score was in the average range but below

the cutoff point for admission to the class. It was also

considerably below what his teachers had estimated

based on his classroom performance. A closer look at his

subtest scores revealed that his performances on Block

Design and Coding were significantly below those on

the other subtests. A follow-up interview with Harold

was quite revealing. Since early childhood, he had

suffered from muscular weakness in both arms and

hands. This weakness prevented him from making fine,

quick motor responses. However, he had developed a

number of clever compensations to prevent others from

guessing his limitation. For example, what had appeared

to be slow, deliberate, even confused responses on Block

Design were really not that at all. He was feigning con-

fusion to mask his difficulty with fine motor functions.

Clearly, then, Harold’s IQ score had been unduly affected

by a motor weakness that had nothing to do with his

ability to perform intellectually.

THE ASSESSMENT OF INTELLIGENCE 213