Intelligence and its Measurement. What Is Intelligence? Intelligence Defined: Views of the Lay...

Intelligence and its Measurement

What Is Intelligence?

• Intelligence Defined: Views of the Lay Public

• Sternberg et al (1981, 1982, 1986)• Cognitive rather than psychometric

• Computational, experiential, and practical

What is Intelligence? (cont’d.)

• Intelligence Defined: Views of Scholars and Test Professionals– Sir Francis Galton: Intelligence is dependent on sensory input

– Alfred Binet: Practical Approach: IQ=Educable?

– David Wechsler: Intelligence = Aggregate of abilities

– Jean Piaget: Intelligence = function of maturation

– Factor-Analytic Theories of Intelligence

– The Information-Processing View


– Factor-Analytic Theories of Intelligence


– The Information-Processing View

Howard Gardner’sMultiple Intelligence Model

(1943- )

• Logical-Mathematical

• Spatial

• Linguistic

• Bodily-Kinesthetic

• Musical

• Interpersonal

• Intrapersonal

• Naturalistic

• Existential

& Naturalist

Measuring Intelligence

• Types of Tasks Used in Intelligence Tests– Infants– Children– Adults

• Theory in Intelligence Test Development and Interpretation

Intelligence: Some Issues

• Nature Versus Nurture– Inheritance and interactionism

• The Stability of Intelligence• The Construct Validity of Tests of Intelligence• Other Issues

– The measurement process– Personality– Gender– Family environment– Culture

Sample Items from the Chitling Intelligence Test[Adrian Dove]

1.A "handkerchief head" is:• (a) a cool cat, (b) a porter, (c) an Uncle Tom, (d) a hoddi, (e)

a preacher.



a preacher.2.Which word is most out of place here?

• (a) splib, (b) blood, (c) gray, (d) spook, (e) black.




• (a) splib, (b) blood, (c) gray, (d) spook, (e) black.3. A "gas head" is a person who has a:

• (a) fast-moving car, (b) stable of "lace," (c) "process," (d) habit of stealing cars, (e) long jail record for arson.






4."Bo Diddley" is a:1. (a) game for children, (b) down-home cheap wine, (c) down-

home singer, (d) new dance, (e) Moejoe call.






4."Bo Diddley" is a:1. (a) game for children, (b) down-home cheap wine, (c) down-

home singer, (d) new dance, (e) Moejoe call.• "Hully Gully" came from:

1. (a) East Oakland, (b) Fillmore, (c) Watts, (d) Harlem, (e) Motor City.

Verbal Subtests

Information:

•Who was the “father of our country?

•What is the population of the United States?

•At what temperature does ice freeze?

Verbal Subtests

Similarities

•In what way are red and green alike?

•How are a worm and a chicken alike?

•In what way are loud and soft alike?

Verbal Subtests

Vocabulary

•What is an orange?

•What does considerate mean?

•What does deprecate mean?

•What does pusillanimous mean?

Verbal Subtests

Comprehension

•How would you find your way out if you were lost in the

forest without a compass?

•What is a purpose of the United Nations?

•Why might money become obsolete?

Verbal Subtests

Digit Span

•Repeat these numbers

5-4-9; 3-8-5

4-7-1-8; 4-9-6-2

8-4-9-6-2; 9-4-3-5-1

•Repeat these numbers backward:

2-8-4; 9-5-3

6-8-2-5; 4-9-7-1

4-1-7-6-3-5; 1-5-9-7-3-8

Verbal Subtests

Arithmetic

•If you bought $3.58 in merchandise and gave the

storekeeper a $20.00 bill, how much change should

you get back?

•If a $900 TV set is on sale for 1/3 off, how much

would it cost?

•Sales tax is 7-percent; how much would a $146 suit

cost, sales tax included?

Performance Subtests

•Block Design

•Matrix Reasoning

•Visual Puzzles

•Picture Completion

•Figure Weights

•Symbol Search

•Coding

Block Design

Matrix Reasoning

Visual Puzzles

Q: "Which 3 of these pieces go together to make this puzzle?"A: "Options 1, 3 and 6 go together to make this puzzle.”

• Picture Completion

“What is missing in this picture?

Figure Weights

Q: "Which one of these goes here to balance the scale?"A: "Option 2 goes there to balance the scale.”

• Coding

Supplemental Examples

"When I say go, draw a line through each red square and yellow triangle."

Cognitively Impaired(Mental Retardation)

Significantly subaverage intellectual functioning

Concurrently with limitation in adaptive skills

Manifested before age 18

Four assumptions essential to understanding and appropriately applying the definition

1. Limitations in present functioning must be considered within the context of community environments typical of the individual’s age peers and culture.

2. Valid assessment considers cultural and linguistic diversity as well as differences in communication, sensory, motor, and behavioral factors.

3. Within the individual, limitations often coexist with strengths.

4. With appropriate personalized supports over a sustained period, the life functioning of the person with intellectual disability generally will improve.

Assessing Adaptive Behavior

Adaptive behavior is the collection of conceptual, social, and practical skills that have been learned by people in order to function in their everyday lives.

Measurement of adaptive behavior has proven difficult because of the relative nature of social adjustment and competence.

Identification and Assessment

Assessing Intellectual Functioning • Standardized tests are used to assess intelligence

– A diagnosis of MR requires an IQ score at least 2 standard deviations below the mean (70 or less)

• Important considerations of IQ tests: – IQ is a hypothetical construct– IQ tests measure how a child performs at one point in time– IQ tests can be culturally biased– IQ scores can change significantly– IQ testing is not an exact science– Results are not useful for targeting educational objectives

• Results should never be used as the sole basis for making decisions regarding special education services

Subaverage intellectual functioning

I.Q. 2 or more standard deviations below the mean

on a valid & reliable individually administered test

generally I.Q<70-75 (Mean=100, =15)

Deficits in 2 or morerelated adaptive skill

areas

communication

self-care

home living

social skills

community use

self-direction Oh! Gosh, whichone should I wear?I can’t decide, thisone? No this one?Ooooooh!!!

health and safety

academics

leisure

Manifested before age 18

18 is somewhat arbitraryrepresents the end of the

developmental period

Characteristics of Students with MR

• Mild MR– Usually not identified until school age– Most students master many academic skills– Most able to learn job skills well enough to support themselves

independently or semi-independently

• Moderate MR– Most show significant delays in development during the preschool

years– As they grow older the discrepancies in age-related adaptive and

intellectual skills widens

• Severe MR– Usually identified at birth– Most have significant central nervous system damage– Likely to have health care problems that require intensive supports

Prevalence and Causes

Prevalence• During the 2005–2006 school year,

approximately 0.81% of the total school enrollment received special education services in the MR category and 9.6% of the total school-age population

Causes• More than 350 causes of MR have been

identified

Biological CausesPrenatal causes include:

Down syndromeFetal alcohol spectrum disordersFragile X syndrome Klinefelter syndromePhenylketonuriaPrader-Willi syndromeWilliams syndrome

Perinatal causes include:Intrauterine disordersNeonatal disorders

Postnatal causes include:Head injuriesInfectionsDegenerative disordersMalnutrition

Trisomy-21

Down Syndrome

Maternal age & risk for Down Syndrome

Amniocentesis

Features of FAS• FAS features are variable. They may or may not be present in a given

child. However, the most common and consistent features of FAS involve the growth, performance, intelligence, head and face, skeleton, and heart of the child.

• Growth is diminished. Birth weight is lessened. The growth lag is permanent.

• Performance is impaired. The FAS infant is irritable. The older FAS child is hyperactive. Fine motor skills are impaired with weak grasp, poor eye-hand coordination, & tremors.

• Average IQ is in the 60s. (This level is considered mild mental retardation).

• The head is small (microcephalic). This decrease may not even be apparent to family and friends. It is primarily due to failure of brain growth.

Fetal

alcohol spectrum

disorders

Fragile X Syndrome

Environmental Causes

• Minimal opportunities to develop early language

• Child abuse and neglect

• Chronic social or sensory deprivation

Longitudinal Studies of Early Intervention:

• Harold Skeels

• Series of studies done by Skeels and associates (1930s – 1960s)

• Skeels & Skodak: Series of studies of 100 adopted children

• Skeels & Dye: Skeels (1942) and Skeels (1966): best-known most-quoted research in the field

Results with Skeels & Dye children1. Experimental group

– N = 13 10 boys 3 girls

– CA = 18 months IQ = 64.3

2. Control Group

– N = 12

– CA = 16 months IQ = 86.7

3. Treatment

– Experimental group – mentally retarded, unsuitable for adoption; placed with retarded woman in institution

– Control group remained in orphanage

4. 1939 results

– Experimental group CA = 38 months IQ = 91.8

• + 27.5 IQ points

– Control group CA = 47 months IQ = 60.5

• –26.2 IQ point

5. 1942 results

– Experimental groupCA = 71 months IQ = 95.9

• + 31.6 IQ points

6. Control group CA = 83 months IQ = 66.1

• –20.6 IQ points

7. 1966 follow-up

– Experimental group

• 11 adopted in good homes

• 2 retained since still in MR range

• 11 married, 1 divorced, 2 not married

• 9 had children

8. Control group

– 11 living, 2 married, 1 divorced

– 5 in institutions, rest blue collar except one whose educational

– achievement and income equaled total of others combined

Variables Associated with Psychosocial Retardation

Prenatal• Poor nutrition

• Inadequate prenatal care

• Illegitimacy

• Mother working

• Pregnancy itself

• Early age

• High number

• Close intervals

• Late in age

Variables Associated with Psychosocial Retardation (cont’d)

Postnatal

• Language development

• Role Models

• Type of language

• Limitations on conceptualizations

• Stimulation

Physical environment

• Single parent

• Crowded living situation

• Poor nutrition and medical/health care

Teratogens (Infections&Toxins)

• Rubella (German measles)

• Heavy Metals (Pb, Hg)

• STDs (syphilis, AIDS, herpes simplex)

• Rh incompatibility

• Toxoplasmosis

• Carbon monoxide

• Medications, prescription or non-prescription

• Meningitis

• Encephalitis

Meningitis

Prevention• The biggest single preventive strike against MR was the

development of the rubella vaccine in 1962

• Toxic exposure through maternal substance abuse and environmental pollutants are two major causes of preventable MR that can be combated with education and training

• Advances in medical science have enabled doctors to identify certain genetic influences

• Although early identification and intensive educational services to high-risk infants show promise, there is still no widely used technique to decrease the incidence of MR caused by psychosocial disadvantage

Intelligence and its Measurement. What Is Intelligence? Intelligence Defined: Views of the Lay...

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