Clinical Psychology

T

he history of clinical psychology is inextricably

tied to the assessment of intelligence. Without

the success in this and related assessment enterprises,

there might not have been a field of clinical psy-

chology. As the years passed, however, clinicians

became increasingly interested in other aspects of

the profession, such as therapy. Assessment began

to take a back seat, and technicians started to

conduct assessments, as they had prior to World

War II. However, as indicated in earlier chapters,

assessment experienced a renaissance of sorts. Intel-

ligence tests in particular remain prominent in the

clinical psychologist’s arsenal of assessment devices

(Camara, Nathan, & Puente, 2000).

In this chapter, we provide some background

relevant to the controversies over intellectual assess-

ment, present major definitions and theories of intel-

ligence, focus on the measurement of intelligence,

and finally, discuss the appropriate interpretation of

intelligence test scores.

Intelligence Testing: Yesterday and Today

Several important historical developments in the lat-
ter half of the 19th century greatly influenced the
ultimate introduction of measures of intelligence
(Hunt, 2011; Thorndike, 1997; Wasserman &
Tulsky, 2005; White, 2006). First, compulsory edu-
cation in the United States and other countries
resulted in a very diverse student body. Many stu-
dents came from“uneducated”families or families
that did not speak English. As a result, the failure
rate in schools shot up dramatically. To preserve
resources, there was pressure to identify those most
likely to succeed in school. Second, psychological
scientists believed, and ultimately demonstrated,
that mental abilities could be measured. Although
early attempts focused primarily on measures of sen-
sory acuity and reaction time (e.g., Francis Galton,
James McKeen Cattell), the groundwork was laid.

Alfred Binet and his collaborator, Theodore

Simon, became leaders in the intelligence testing

movement when they devised the Binet-Simon

test to identify individual differences in mental func-

tioning (see Chapter 2). Binet’s original purpose was

to develop an objective method of identifying those

truly lacking in academic ability (as opposed to those

with behavior problems). Like others of the day,

Binet and Simon regarded intelligence as a“faculty”

that was inherited, although they also spoke of it as

affected by training and opportunity. With the

interest in quantifying intellectual performance and

with the continuing growth of compulsory educa-

tion in Europe and North America, intelligence

testing became firmly entrenched (Hunt, 2011;

Thorndike, 1997; Wasserman & Tulsky, 2005).

Institutions such as schools, industries, military

forces, and governments were, by their nature,

interested in individual differences (e.g., levels of

intelligence) that might affect performance in

those settings; therefore, intelligence testing pros-

pered. For many years, the critical importance and

F I G U R E 7-1 Alfred Binet developed the first widely

accepted test of intelligence. The test, which eventually

became the Stanford-Binet, has undergone numerous

revisions over the years.

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192 CHAPTER 7