clinical psychology

1. Intelligence TestsIntelligence Tests
Lecture 18Lecture 18

2. DefinitionDefinition
““Intelligence tests are psychological tests thatIntelligence tests are psychological tests that
are designed to measure a variety of mentalare designed to measure a variety of mental
functions, such as reasoning, comprehension,functions, such as reasoning, comprehension,
and judgment”.and judgment”.
PurposePurpose
To obtain an idea of the person's intellectualTo obtain an idea of the person's intellectual
potential.potential.

3. Precautions with Intelligence TestsPrecautions with Intelligence Tests
 There are many different types of intelligenceThere are many different types of intelligence
tests and they all do not measure the sametests and they all do not measure the same
abilities.abilities.
 The test should be adequately developed andThe test should be adequately developed and
have solid research to show its reliability andhave solid research to show its reliability and
validity.validity.
 Test should only be administered andTest should only be administered and
interpreted by a trained professional.interpreted by a trained professional.

4. Criticism of intelligence testsCriticism of intelligence tests
 A central criticism : psychologists and educators use theseA central criticism : psychologists and educators use these
tests to distribute the limited resources of our society.tests to distribute the limited resources of our society.
 Intelligence test scores have not only become associated with aIntelligence test scores have not only become associated with a
person's ability to perform certain tasks, but with self-worth.person's ability to perform certain tasks, but with self-worth.
 False assumptions about biological or environmentalFalse assumptions about biological or environmental
intelligence.intelligence.
 Associated with categorizing and stereotyping people.Associated with categorizing and stereotyping people.
 May affect a person's aspirations and motivation to obtainMay affect a person's aspirations and motivation to obtain
goals.goals.
 Can be culturally biased against certain groups.Can be culturally biased against certain groups.

5. Common ProceduresCommon Procedures
 A person can expect to do a variety of tasks.A person can expect to do a variety of tasks.
 E.g., having to answer questions that are askedE.g., having to answer questions that are asked
verbally, doing mathematical problems, and doing averbally, doing mathematical problems, and doing a
variety of tasks that require eye-hand coordination.variety of tasks that require eye-hand coordination.
 Some tasks may be timed and require the person toSome tasks may be timed and require the person to
work as quickly as possible.work as quickly as possible.
 Most questions and tasks start out easy andMost questions and tasks start out easy and
progressively get more difficult.progressively get more difficult.

6. Common Procedures (contd.)Common Procedures (contd.)
 Raw scores on an intelligence test are typicallyRaw scores on an intelligence test are typically
converted to standard scores for comparison.converted to standard scores for comparison.
 Depending on the intelligence test that is used, aDepending on the intelligence test that is used, a
variety of scores can be obtained.variety of scores can be obtained.
 Most intelligence tests generate an overallMost intelligence tests generate an overall
intelligence quotient or IQ.intelligence quotient or IQ.
 It is valuable to know how a person performs on theIt is valuable to know how a person performs on the
various tasks that make up the test. This canvarious tasks that make up the test. This can
influence the interpretation of the test and what theinfluence the interpretation of the test and what the
IQ means.IQ means.

7. AdvantagesAdvantages
 Intelligence tests measure a wide variety of humanIntelligence tests measure a wide variety of human
behaviors.behaviors.
 Allow professionals to have a uniform way ofAllow professionals to have a uniform way of
comparing a person's performance with that of othercomparing a person's performance with that of other
people who are similar in age.people who are similar in age.
 Also provide information on cultural and biologicalAlso provide information on cultural and biological
differences among people.differences among people.
 Excellent predictors of academic achievement andExcellent predictors of academic achievement and
provide an outline of a person's mental strengths andprovide an outline of a person's mental strengths and
weaknesses.weaknesses.

8. DisadvantagesDisadvantages
 Some researchers argue that intelligence tests haveSome researchers argue that intelligence tests have
serious shortcomings. For example, many intelligenceserious shortcomings. For example, many intelligence
tests produce atests produce a single intelligence score.single intelligence score.
 This single score is often inadequate in explaining theThis single score is often inadequate in explaining the
multidimensional aspects of intelligence.multidimensional aspects of intelligence.
 Individuals with similar intelligence test scores canIndividuals with similar intelligence test scores can
vary greatly in their expression of these talents.vary greatly in their expression of these talents.
 For example, strong verbal skills vs. strong skills inFor example, strong verbal skills vs. strong skills in
perceiving and organizing various tasks may lead twoperceiving and organizing various tasks may lead two
people to have identical scores on intelligence tests. .people to have identical scores on intelligence tests. .

9.  Intelligence tests only measure a sample of behaviorsIntelligence tests only measure a sample of behaviors
or situations in which intelligent behavior is revealed.or situations in which intelligent behavior is revealed.
 For instance, some intelligence tests do not measureFor instance, some intelligence tests do not measure
a person's everyday functioning, social knowledge,a person's everyday functioning, social knowledge,
mechanical skills, and/or creativity.mechanical skills, and/or creativity.
 The formats of many intelligence tests do not captureThe formats of many intelligence tests do not capture
the complexity and immediacy of real-life situations.the complexity and immediacy of real-life situations.
 Limited ability to predict non-test or nonacademicLimited ability to predict non-test or nonacademic
intellectual abilities.intellectual abilities.

10. Commonly Used IntelligenceCommonly Used Intelligence
TestsTests
 The three most commonly used intelligenceThe three most commonly used intelligence
tests are:tests are:
 Stanford-Binet Intelligence ScalesStanford-Binet Intelligence Scales
 Wechsler-Adult Intelligence ScaleWechsler-Adult Intelligence Scale
 Wechsler Intelligence Scale for ChildrenWechsler Intelligence Scale for Children

11. Concepts of IQ &Concepts of IQ &
Deviation IQDeviation IQ

12. THE INTELLIGENCETHE INTELLIGENCE
QUOTIENT (IQ)QUOTIENT (IQ)
 RATIO IQRATIO IQ: Binet regarded the mental age (MA) as an: Binet regarded the mental age (MA) as an
index of mental performance. Each item successfullyindex of mental performance. Each item successfully
passed on a Binet test signified a certain number ofpassed on a Binet test signified a certain number of
months' credit.months' credit.
 At the conclusion of the test, the items passed wereAt the conclusion of the test, the items passed were
added up and the Mental Age (MA) emerged.added up and the Mental Age (MA) emerged.
 Subsequently, Stern (1938) developed the concept ofSubsequently, Stern (1938) developed the concept of
intelligence quotient (1Q) to circumvent severalintelligence quotient (1Q) to circumvent several
problems that had arisen in using the differenceproblems that had arisen in using the difference
between the chronological age (CA) and the MA tobetween the chronological age (CA) and the MA to
express deviance.express deviance.

13. Computation of The IQComputation of The IQ
 The IQ notion enables us to perform the followingThe IQ notion enables us to perform the following
computation:computation:
IQ=MA/CA x 100IQ=MA/CA x 100
 IQs and MAs are merely scores. We can not add orIQs and MAs are merely scores. We can not add or
subtract IQ scores.subtract IQ scores.
 All we can do is state that a person with an IQ of 50 isAll we can do is state that a person with an IQ of 50 is
brighter than a person with an IQ of 25.brighter than a person with an IQ of 25.

14. Deviation IQ:Deviation IQ:
 Although initially appealing, the ratio IQ isAlthough initially appealing, the ratio IQ is
significantly limited in its application to oldersignificantly limited in its application to older
age groups.age groups.
 To deal with this problem, WechslerTo deal with this problem, Wechsler
introduced the concept ofintroduced the concept of deviation IQ.deviation IQ.
 The assumption is made that intelligence isThe assumption is made that intelligence is
normally distributed throughout the population.normally distributed throughout the population.
 A deviation IQ then involves a comparison ofA deviation IQ then involves a comparison of
an individual's performance on an IQ test withan individual's performance on an IQ test with
that of his or her age peers.that of his or her age peers.

15. The ClinicalThe Clinical
Assessment OfAssessment Of
IntelligenceIntelligence

16. The Stanford - Binet ScaleThe Stanford - Binet Scale
The Stanford-Binet Intelligence Scale: Fourth EditionThe Stanford-Binet Intelligence Scale: Fourth Edition
(SB: FE) is a standardized test that measures(SB: FE) is a standardized test that measures
intelligence and cognitive abilities in children andintelligence and cognitive abilities in children and
adults, from age two through mature adulthood.adults, from age two through mature adulthood.
 It is a descendant of theIt is a descendant of the Binet-Simon scaleBinet-Simon scale whichwhich
was developed in 1905 and became the firstwas developed in 1905 and became the first
intelligence test.intelligence test.
 TheThe Stanford-BinetStanford-Binet Intelligence Scale wasIntelligence Scale was
developed indeveloped in 19161916 and was revised inand was revised in 19371937,, 19601960,,
andand 19861986. The present. The present (4th)(4th) edition was published inedition was published in
19861986 and is calledand is called SB-4SB-4..

17. PurposePurpose
 Originally developed to help place children inOriginally developed to help place children in
appropriate educational settings.appropriate educational settings.
 It can help determine the level of intellectual andIt can help determine the level of intellectual and
cognitive functioning in preschoolers, children,cognitive functioning in preschoolers, children,
adolescents and adults.adolescents and adults.
 Can assist in theCan assist in the diagnosisdiagnosis of a learning disability,of a learning disability,
developmental delay,developmental delay, mental retardationmental retardation, or, or
giftedness.giftedness.
 It is used to provide educational planning andIt is used to provide educational planning and
placement, neuropsychological assessment, andplacement, neuropsychological assessment, and
research.research.

18. DescriptionDescription
 The Stanford-Binet Intelligence Scale is comprised ofThe Stanford-Binet Intelligence Scale is comprised of
15 subtests, which are grouped into four cognitive15 subtests, which are grouped into four cognitive
area scores which together determine the compositearea scores which together determine the composite
score and factor scores.score and factor scores.
 These area scores include:These area scores include: Verbal ReasoningVerbal Reasoning,,
Abstract/Visual ReasoningAbstract/Visual Reasoning,, QuantitativeQuantitative
ReasoningReasoning, and, and Short-Term MemoryShort-Term Memory..
 The composite score is a global estimate of a person'sThe composite score is a global estimate of a person's
intellectual functioning (a representation ofintellectual functioning (a representation of ““gg”” factor.factor.

19. 1. Verbal reasoning:1. Verbal reasoning: vocabulary,vocabulary,
comprehension, absurdities, verbal relationscomprehension, absurdities, verbal relations
2. Abstract/visual reasoning:2. Abstract/visual reasoning: pattern analysis,pattern analysis,
copying, matrices, paper folding and cutting.copying, matrices, paper folding and cutting.

20. 3. Quantitative reasoning:3. Quantitative reasoning: quantitative,quantitative,
number series, equation building.number series, equation building.
4. Short-term memory:4. Short-term memory: bead memory,bead memory,
memory for sentences, memory for digits,memory for sentences, memory for digits,
memory for objects.memory for objects.

21.  Multistage testing:Multistage testing: Each subtest is composedEach subtest is composed
of items at varying levels of difficulty, from ageof items at varying levels of difficulty, from age
2 to adulthood.2 to adulthood.
 The examiner first gives the Vocabulary Test toThe examiner first gives the Vocabulary Test to
determine the entry point (that is, which item todetermine the entry point (that is, which item to
start with) for each remaining subtest.start with) for each remaining subtest.
 Not all examinees of the same age are givenNot all examinees of the same age are given
the same items.the same items.

22. The Wechsler ScalesThe Wechsler Scales
WAIS :WAIS : DavidDavid Wechsler used a deviation IQWechsler used a deviation IQ
concept. This approach assumes thatconcept. This approach assumes that
intelligence is normally distributed andintelligence is normally distributed and
compares individuals with their age peers.compares individuals with their age peers.
 This method statistically establishes an IQ ofThis method statistically establishes an IQ of
100 as the mean for each age group.100 as the mean for each age group.
 As a result, an IQ of 100 means the same thingAs a result, an IQ of 100 means the same thing
for any person, regardless of the person's age.for any person, regardless of the person's age.

23. Background of WAISBackground of WAIS
Earlier versions of the Stanford-Binet had a number ofEarlier versions of the Stanford-Binet had a number of
disadvantages that led David Wechsler in 1939 todisadvantages that led David Wechsler in 1939 to
develop the Wechsler-Bellevue Intelligence Scale.develop the Wechsler-Bellevue Intelligence Scale.
 It offered items whose content was more appropriateIt offered items whose content was more appropriate
for and more motivating to adults than the school-for and more motivating to adults than the school-
oriented Binet test.oriented Binet test.
 The Wechsler-Bellevue Intelligence Scale grouped itsThe Wechsler-Bellevue Intelligence Scale grouped its
items into subtests in order of increasing difficulty.items into subtests in order of increasing difficulty.
 Performance Scale & Verbal Scale = Full Scale IQ.Performance Scale & Verbal Scale = Full Scale IQ.

24. The WAIS-IIIThe WAIS-III
 Wechsler-Bellevue Intelligence Scale : 1939Wechsler-Bellevue Intelligence Scale : 1939
 Wechsler Adult Intelligent Scale (WAIS) : 1955Wechsler Adult Intelligent Scale (WAIS) : 1955
 WAIS-R (revised): 1981WAIS-R (revised): 1981
 WAIS-III (Wechsler Adult Intelligent Scale-ThirdWAIS-III (Wechsler Adult Intelligent Scale-Third
Edition ) : 1997Edition ) : 1997
 WAIS – III is an individually administered measure ofWAIS – III is an individually administered measure of
intelligence, intended for adults aged 16–89.intelligence, intended for adults aged 16–89.

25. PurposePurpose
 Intended to measure human intelligence reflected inIntended to measure human intelligence reflected in
both verbal and performance abilities.both verbal and performance abilities.
 Used in neuropsychological evaluationUsed in neuropsychological evaluation
 The WAIS-III is also administered for diagnosticThe WAIS-III is also administered for diagnostic
purposes.purposes.
 E.g.,E.g., mental retardationmental retardation, specific learning disabilities,, specific learning disabilities,
andand attention-deficit/hyperactivity disorderattention-deficit/hyperactivity disorder (ADHD).(ADHD).

26.  The WAIS elicits three intelligence quotientThe WAIS elicits three intelligence quotient
scores : an overall intelligence quotient, calledscores : an overall intelligence quotient, called
the full-scale IQ, as well as a verbal IQ and athe full-scale IQ, as well as a verbal IQ and a
performance IQ.performance IQ.
 The WAIS also elicits four indices, each basedThe WAIS also elicits four indices, each based
on a different set of subtests:on a different set of subtests: verbalverbal
comprehensioncomprehension,, perceptual organizationperceptual organization,,
working memoryworking memory, and, and processing speedprocessing speed..
ResultsResults

27. The Verbal IQThe Verbal IQ
VEBAL SUBSETSVEBAL SUBSETS
 information,information,
 digit span,digit span,
 vocabulary,vocabulary,
 arithmetic,arithmetic,
 comprehension,comprehension,
 similarities, andsimilarities, and
 letter-number sequencingletter-number sequencing

28. The Performance IQThe Performance IQ
SUBSETSSUBSETS
 picture completion,picture completion,
 picture arrangement,picture arrangement,
 block design,block design,
 object assembly,object assembly,
 digit symbol,digit symbol,
 matrix reasoning, andmatrix reasoning, and
 symbol searchsymbol search

29. PrecautionsPrecautions
 WAIS III is not considered adequate measureWAIS III is not considered adequate measure
of extremely high and low intelligence.of extremely high and low intelligence.
 The age range for the WAIS III overlaps withThe age range for the WAIS III overlaps with
that of thethat of the WISCWISC for people between 16 and 17for people between 16 and 17
years of age (WISC provides a better measureyears of age (WISC provides a better measure
for this age range).for this age range).
 WAIS administrators must receive properWAIS administrators must receive proper
training and be aware of all test guidelines.training and be aware of all test guidelines.

30. The WISC-IIIThe WISC-III
 WISC III is an individually administeredWISC III is an individually administered
measure of intelligence intended for childrenmeasure of intelligence intended for children
aged six years to 16 years and 11 months.aged six years to 16 years and 11 months.
 First developed in 1949 (WISC),First developed in 1949 (WISC),
 Revised in 1974 (WISC-R),Revised in 1974 (WISC-R),
 The latest version, the Wechsler Intelligence Scale forThe latest version, the Wechsler Intelligence Scale for
Children-Third Edition (WISC-III),Children-Third Edition (WISC-III), was published inwas published in
1991.1991.

31. PurposesPurposes
 Designed to measure human intelligence as reflectedDesigned to measure human intelligence as reflected
in both verbal and nonverbal (performance) abilities.in both verbal and nonverbal (performance) abilities.
 Used in schools as part of placement evaluations forUsed in schools as part of placement evaluations for
programs for gifted children and for children who areprograms for gifted children and for children who are
developmentally disabled.developmentally disabled.
 Neuropsychological evaluation, specifically with regardNeuropsychological evaluation, specifically with regard
toto brainbrain dysfunction.dysfunction.
 Also used for other diagnostic purposes.Also used for other diagnostic purposes.

32. ResultsResults
 WISC III scores yield an overall intelligenceWISC III scores yield an overall intelligence
quotient, called thequotient, called the full scale IQfull scale IQ, as well as a, as well as a
verbal IQverbal IQ and aand a performance IQperformance IQ..
 Verbal and performance IQ scores are basedVerbal and performance IQ scores are based
on scores on the 13 subtests.on scores on the 13 subtests.
 The full scale IQ is derived from the child'sThe full scale IQ is derived from the child's
scores on all of the subtests and reflects bothscores on all of the subtests and reflects both
verbal IQ and performance IQ.verbal IQ and performance IQ.

33. Verbal IQVerbal IQ
 The child's verbal IQ score is derived fromThe child's verbal IQ score is derived from
scores on six of the subtests:scores on six of the subtests:
 information,information,
 digit span,digit span,
 vocabulary,vocabulary,
 arithmetic,arithmetic,
 comprehension,comprehension,
 similarities.similarities.

34. Performance IQPerformance IQ
 The child's performance IQ is derived fromThe child's performance IQ is derived from
scores on the remaining seven subtests:scores on the remaining seven subtests:
 picture completion,picture completion,
 picture arrangement,picture arrangement,
 block design,block design,
 object assembly,object assembly,
 coding,coding,
 mazes,mazes,
 symbol search.symbol search.

35. ConclusionConclusion
The Clinical Use Of IntelligenceThe Clinical Use Of Intelligence
TestsTests

36.  The estimation of general intellectual levelThe estimation of general intellectual level
 Prediction of academic successPrediction of academic success
 The appraisal of style (person’sThe appraisal of style (person’s
characteristics)characteristics)