Intelligence refers to mental abilities such as reasoning, problem-solving, and learning. While efforts have been made to define and measure intelligence quantitatively, it remains a complex construct. Theories of intelligence include Spearman's two-factor theory, Cattell's fluid and crystallized intelligence, and Gardner's theory of multiple intelligences. Intelligence testing has practical and scientific significance but also controversies regarding definitions, biases, and appropriate uses. The most influential tests are Wechsler's which view intelligence as related verbal and non-verbal abilities. Continued revisions aim to make tests concurrent while new norms update comparisons.

1. THE CONCEPT OFTHE CONCEPT OF
INTELLIGENCEINTELLIGENCE
Lecture 17Lecture 17

2. IntroductionIntroduction
Intelligence is the mental capacity to reason,Intelligence is the mental capacity to reason,
plan, solve problems, think abstractly,plan, solve problems, think abstractly,
comprehend ideas and language, and learn.comprehend ideas and language, and learn.
Generally considered as distinct fromGenerally considered as distinct from
creativity, personality, character, or wisdom.creativity, personality, character, or wisdom.

3. The Concept Of IntelligenceThe Concept Of Intelligence
 The concept of intelligence has presented clinical psychologyThe concept of intelligence has presented clinical psychology
with one of its greatest dilemmas.with one of its greatest dilemmas.
 Despite efforts to quantify individual differences in intellectualDespite efforts to quantify individual differences in intellectual
functioning for over a 100 years, intelligence has remainedfunctioning for over a 100 years, intelligence has remained
one of the most difficult and controversial psychologicalone of the most difficult and controversial psychological
constructs to define and measure.constructs to define and measure.
 Practical and Scientific significance to define and quantifyPractical and Scientific significance to define and quantify
intelligenceintelligence
 Practical significance : use of measures of intelligence inPractical significance : use of measures of intelligence in
predicting academic and work potential and achievement.predicting academic and work potential and achievement.
 Scientific perspective : for a comprehension of an importantScientific perspective : for a comprehension of an important
aspect of human behavior and functioning (intelligence).aspect of human behavior and functioning (intelligence).

4. Two unresolved issues of intelligence:Two unresolved issues of intelligence:
1.1. Exactly what is meant by the termExactly what is meant by the term
intelligence?intelligence?
Because the precise definition of intelligenceBecause the precise definition of intelligence
differs from psychologist to psychologist. E.g.,differs from psychologist to psychologist. E.g.,
 innate general cognitive abilityinnate general cognitive ability
 a set of skills of problem solvinga set of skills of problem solving
 goal-directed adaptive behaviorgoal-directed adaptive behavior

5. 2.2. How do we develop valid instruments forHow do we develop valid instruments for
measuring it?measuring it?
 Psychometric concepts of reliability andPsychometric concepts of reliability and
validity:validity:
ReliabilityReliability ::
Consistency of a set of measurements orConsistency of a set of measurements or
measuring instrument.measuring instrument.
It is the consistency with which individualsIt is the consistency with which individuals
respond to test stimuli.respond to test stimuli.

6. Types of ReliabilityTypes of Reliability
There are several ways of evaluating reliability.There are several ways of evaluating reliability.
1.1. Test-retest reliabilityTest-retest reliability
2.2. Equivalent-forms reliabilityEquivalent-forms reliability
3.3. Split-half reliabilitySplit-half reliability
4.4. Inter-raterInter-rater oror inter-judge reliabilityinter-judge reliability

7. ValidityValidity
 The extent to which as assessment techniqueThe extent to which as assessment technique
measures what it is supposed to measure.measures what it is supposed to measure.
 Getting results that accurately reflect the conceptGetting results that accurately reflect the concept
being measured.being measured.
Types Of ValidityTypes Of Validity::
 Content ValidityContent Validity indicates the degree to which aindicates the degree to which a
group of test items actually covers the variousgroup of test items actually covers the various
aspects of the variable under study.aspects of the variable under study.

8.  Criterion validityCriterion validity, is to correlate measures with a, is to correlate measures with a
criterion measure known to be valid.criterion measure known to be valid.
 Concurrent ValidityConcurrent Validity involves relating today’s testinvolves relating today’s test
scores to a concurrent criterion.scores to a concurrent criterion.
 Predictive ValidityPredictive Validity is demonstrated when testis demonstrated when test
scores accurately predict some behavior or event inscores accurately predict some behavior or event in
the future.the future.
 Construct ValidityConstruct Validity is shown when test scores relateis shown when test scores relate
to other measures or behaviors in a logical,to other measures or behaviors in a logical,
theoretically expected fashion.theoretically expected fashion.

9. Definition Of IntelligenceDefinition Of Intelligence
 No universally accepted definition. However, mostNo universally accepted definition. However, most
have fallen into one of three classes:have fallen into one of three classes:
1.1. Definitions that emphasize adjustment or adaptation toDefinitions that emphasize adjustment or adaptation to
the environment – adaptability to new situations, thethe environment – adaptability to new situations, the
capacity to deal with a range of situations.capacity to deal with a range of situations.
2.2. Definitions that focus on the ability to learn – onDefinitions that focus on the ability to learn – on
educability in the broad sense of the terms.educability in the broad sense of the terms.
3.3. Definitions that emphasize abstract thinking the abilityDefinitions that emphasize abstract thinking the ability
to use a wide range of symbols and concepts, theto use a wide range of symbols and concepts, the
ability to use both verbal and numerical symbols.ability to use both verbal and numerical symbols.

10. Some DefinitionsSome Definitions
 Intelligence is the aggregate or global capacity ofIntelligence is the aggregate or global capacity of
the individual to act purposefully, to thinkthe individual to act purposefully, to think
rationally, and to deal effectively with hisrationally, and to deal effectively with his
environment.environment.
(Wechsler, 1939)(Wechsler, 1939)
 As a concept, intelligence refers to the wholeAs a concept, intelligence refers to the whole
class of cognitive behaviors which reflect anclass of cognitive behaviors which reflect an
individual’s capacity to solve problems withindividual’s capacity to solve problems with
insight, to adapt himself to new situations, to thinkinsight, to adapt himself to new situations, to think
abstractly, and to profit from his experience.abstractly, and to profit from his experience.
(Robinson & Robinson, 1965)(Robinson & Robinson, 1965)

11. In general we can say that :In general we can say that :
 Intelligence is aIntelligence is a very general mental capabilityvery general mental capability that,that,
among other things, involves theamong other things, involves the ability to reasonability to reason,,
planplan,, solve problemssolve problems,, think abstractlythink abstractly,,
comprehend complex ideascomprehend complex ideas,, learn quicklylearn quickly andand
learn from experiencelearn from experience..
 A broader and deeper capability for comprehendingA broader and deeper capability for comprehending
our surroundings—"catching on", "making sense" ofour surroundings—"catching on", "making sense" of
things, or "figuring out" what to do.things, or "figuring out" what to do.

12. Theories Of IntelligenceTheories Of Intelligence

13. FACTOR ANALYTICALFACTOR ANALYTICAL
APPROACHESAPPROACHES

Spearman’s “Spearman’s “gg” factor and “” factor and “ss” factor (1927).” factor (1927).

14. Cattell’s Theory:Cattell’s Theory:
 Two important second-order factors that seemTwo important second-order factors that seem
to represent a partitioning of Spearman's “g”to represent a partitioning of Spearman's “g”
into two components:into two components:
 Fluid abilityFluid ability (the person's genetically based(the person's genetically based
intellectual capacity) andintellectual capacity) and
 Crystallized abilityCrystallized ability (the capacities, tapped by(the capacities, tapped by
the usual standardized intelligence test thatthe usual standardized intelligence test that
can be attributed to culture-based learning).can be attributed to culture-based learning).

15. Guilford’s TheoryGuilford’s Theory
 Guilford proposed aGuilford proposed a Structure of the Intellect (SOI) modelStructure of the Intellect (SOI) model

16. TheThe operationsoperations are cognition, memory, divergentare cognition, memory, divergent
production (constructing logical alternatives),production (constructing logical alternatives),
Convergent production (constructing logic-tightConvergent production (constructing logic-tight
arguments), and evaluation. (5)arguments), and evaluation. (5)
TheThe contentcontent dimension involves the areas ofdimension involves the areas of
information in which the operations areinformation in which the operations are
performed: figural, symbolic, semantic, andperformed: figural, symbolic, semantic, and
behavioral. (4)behavioral. (4)
Finally, when a particular mental operation isFinally, when a particular mental operation is
applied to a specific type of content, there are sixapplied to a specific type of content, there are six
possiblepossible productsproducts: units, classes, systems,: units, classes, systems,
relations, transformations, and implications. (6)relations, transformations, and implications. (6)
120 separate intellectual abilities.120 separate intellectual abilities. (5 X 4 X 6 =120)(5 X 4 X 6 =120)

17. Traditional tests used to assess what we knowTraditional tests used to assess what we know
or can do.or can do.
Recent approaches take a highly cognitive orRecent approaches take a highly cognitive or
information-processing look.information-processing look.
e.g., speed of information processing ,e.g., speed of information processing ,
strategies & levels of processing.strategies & levels of processing.
Recent Developments:Recent Developments:

18. Gardner’s Theory OfGardner’s Theory Of MultipleMultiple
IntelligencesIntelligences
 Gardner (1983) : intelligence is a set of problem-Gardner (1983) : intelligence is a set of problem-
solving skillssolving skills
 A family of six intelligences:A family of six intelligences:
linguisticlinguistic,, musicalmusical,, logical-mathematicallogical-mathematical,, spatialspatial,,
bodily-kinestheticbodily-kinesthetic, and, and personalpersonal..
 Criticism:Criticism: “Talents” rather than “intelligences”.“Talents” rather than “intelligences”.

19. Sternberg’sSternberg’s Triarchic Theory OfTriarchic Theory Of
IntelligenceIntelligence
 People function on the basis of three aspectsPeople function on the basis of three aspects
of intelligence:of intelligence:
Componential (Componential (analytical thinkinganalytical thinking)),,
Experiential (Experiential (creative thinkingcreative thinking)), and, and
Contextual (Contextual ("street smartness”"street smartness”))..

20.  The notion of a single IQ score suggests thatThe notion of a single IQ score suggests that
““gg” factor is still considered seriously.” factor is still considered seriously.
 Despite many theories of multiple intelligencesDespite many theories of multiple intelligences
or multiple factors.or multiple factors.
 Most current intelligence tests are composed ofMost current intelligence tests are composed of
subtests, suggesting that practicing clinicianssubtests, suggesting that practicing clinicians
think more in line with Spearman or Thurstone.think more in line with Spearman or Thurstone.

21. History Of IntelligenceHistory Of Intelligence
TestingTesting

22. Intelligence Testing: YesterdayIntelligence Testing: Yesterday
And TodayAnd Today
Two important historical developments in theTwo important historical developments in the
latter half of the nineteenth century greatlylatter half of the nineteenth century greatly
influenced the ultimate introduction ofinfluenced the ultimate introduction of
measures of intelligence:measures of intelligence:
First, compulsory education in the United States.First, compulsory education in the United States.
Second, psychologists’ belief that mental abilitiesSecond, psychologists’ belief that mental abilities
could be measured.could be measured.

23.  Alfred Binet and Theodore Simon becameAlfred Binet and Theodore Simon became
leaders in the intelligence testing movementleaders in the intelligence testing movement
when they devised the Binet-Simon test.when they devised the Binet-Simon test.
 Binet's original purpose was to develop anBinet's original purpose was to develop an
objective method of identifying those trulyobjective method of identifying those truly
lacking in academic ability (not behaviorlacking in academic ability (not behavior
problems).problems).
 Binet and Simon regarded intelligence as aBinet and Simon regarded intelligence as a
"faculty" that was inherited, although they also"faculty" that was inherited, although they also
spoke of it as affected by training andspoke of it as affected by training and
opportunity.opportunity.

24.  Interest in quantifying intellectual performanceInterest in quantifying intellectual performance
 Interest in individual differences (such as levelsInterest in individual differences (such as levels
of intelligence) was taken by institutions suchof intelligence) was taken by institutions such
as schools, industries, military forces, andas schools, industries, military forces, and
government.government.
 Unchallenged & widespread use of intelligenceUnchallenged & widespread use of intelligence
tests for a while, but then attacked fortests for a while, but then attacked for
discriminating through the inclusion of unfairdiscriminating through the inclusion of unfair
items.items.

25. Issue of African AmericansIssue of African Americans
 The California State Board of Education inThe California State Board of Education in
1975 imposed a moratorium on the use of1975 imposed a moratorium on the use of
intelligence tests to assess disabilities inintelligence tests to assess disabilities in
African Americans.African Americans.
 IQ testing is prejudicial to African AmericanIQ testing is prejudicial to African American
children and tends to diagnose them aschildren and tends to diagnose them as
mentally retarded.mentally retarded.
 This became a hotly debated issue.This became a hotly debated issue.

26. The most widely used intelligenceThe most widely used intelligence
tests in the United Statestests in the United States
 The most widely used intelligence tests in the U. S. wereThe most widely used intelligence tests in the U. S. were
developed by David Wechsler during the 1940’s anddeveloped by David Wechsler during the 1940’s and
1950’s.1950’s.
 He based his works on many existing tests.He based his works on many existing tests.
 Wechsler’s belief was that there is a total or global level ofWechsler’s belief was that there is a total or global level of
intellectual capacity that can be measured – thus; his testsintellectual capacity that can be measured – thus; his tests
yield a score that represents the person’s overallyield a score that represents the person’s overall
intelligence.intelligence.
 Wechsler’s tests have shaped psychologist’s perception ofWechsler’s tests have shaped psychologist’s perception of
intellectual functioning as comprised of separate butintellectual functioning as comprised of separate but
related verbal and performance (non-verbal abilities).related verbal and performance (non-verbal abilities).

27. Wechsler’sWechsler’s Functional intelligenceFunctional intelligence
 Wechsler (1939) emphasized that an IQ testWechsler (1939) emphasized that an IQ test
measuresmeasures functional intelligencefunctional intelligence, not intelligence it, not intelligence it
self.self.
 Some non-intellectual factors including motivations &Some non-intellectual factors including motivations &
emotional adjustment can influence functionalemotional adjustment can influence functional
intelligence.intelligence.
 For Wechsler, score on an IQ test is a reflection ofFor Wechsler, score on an IQ test is a reflection of
what one has learned, which is a function of thewhat one has learned, which is a function of the
environmental opportunities.environmental opportunities.

28. Continued Adaptation Of IntelligenceContinued Adaptation Of Intelligence
TestingTesting
 Represented in the history of the Wechsler scalesRepresented in the history of the Wechsler scales
(through revisions).(through revisions).
 These changes have taken two forms:These changes have taken two forms:
1.1. Changes in test items to make them concurrent.Changes in test items to make them concurrent.
2.2. New normative samples to provide up-to-dateNew normative samples to provide up-to-date
sources of comparison.sources of comparison.

29. ConclusionConclusion

30.  Intelligence tests have been misused at timesIntelligence tests have been misused at times
 Some tests have contained certain unfairSome tests have contained certain unfair
items.items.
 Test development, administration, andTest development, administration, and
interpretation requires great sensitivity.interpretation requires great sensitivity.
 However, banning tests seems anHowever, banning tests seems an
inappropriate cure that may ultimately harminappropriate cure that may ultimately harm
the very people who need help.the very people who need help.